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Ad Libitum (ad + libitum)
Kinds of Ad Libitum Terms modified by Ad Libitum Selected AbstractsDietary exposure to low doses of bisphenol A: Effects on reproduction and development in two generations of C57BL/6J miceCONGENITAL ANOMALIES, Issue 3 2010Kenichi Kobayashi Abstract The present study was conducted to examine the effects of low-dose exposure to bisphenol A on reproduction and development in two generations of mice. Pregnant female C57BL/6J mice (F0) were fed a diet containing low doses of bisphenol A (0, 0.33, 3.3, or 33 ppm) from gestational day 6 through postnatal day 22, and the weanlings (F1 and F2) from each F0 and F1 dam group, respectively, were also fed these same concentrations of bisphenol A ad libitum until sacrifice. There were no treatment-related changes in body weight, body weight gain, food consumption, gestation length, or the number of live births on postnatal day 1 in F0 dams between the control group and bisphenol A groups. Sex ratio and viability were similar in all F1 pups. No treatment-related changes were observed in body weight, food consumption, developmental parameters, anogenital distance, or weight of any of the organs (liver, kidney, heart, spleen, thymus, testis, ovary, or uterus) in F1 and F2 adults in either sex. The epididymis weight was slightly higher with 0.33 and 3.3 ppm in F1 males, but this slight increase was neither dose dependent nor seen across generations. There were no treatment-related effects of bisphenol A on cauda epididymal sperm count or sperm motility in F1 or F2 males. These findings indicate that dietary exposure to bisphenol A between 0.33 and 33 ppm does not adversely affect reproduction or development as assessed in two generations of mice. [source] Colony productivity and foundress behaviour of a native wasp versus an invasive social waspECOLOGICAL ENTOMOLOGY, Issue 6 2003Tracy R. Armstrong Abstract., 1.,Colony productivity, prey utilisation, and foundress behaviour of a North American native wasp (Polistes fuscatus) versus an European invasive wasp (Polistes dominulus) were investigated in a controlled field experiment with optimal versus natural foraging conditions. Colonies with the optimal prey foraging conditions were provided with prey ad libitum within an enclosed area. The other colonies foraged in the adjacent field,woodland but had the same nest conditions as the other treatment. 2.,When given prey ad libitum, both wasp species captured similar amounts of prey and the conversion to total offspring biomass was similar. But P. dominulus colonies produced 2.5 times the number of workers as P. fuscatus colonies, reflecting the smaller size of P. dominulus wasps. 3.,Foundresses of P. dominulus were observed more often building or repairing the nest, thereby contributing to the production of colonies with twice as many cells as colonies of P. fuscatus. Foundresses of P. dominulus showed more acts of aggression toward workers than did P. fuscatus foundresses, which was not a function of adult density on the nest. 4.,At the end of the experiment, P. dominulus colonies with optimal prey foraging conditions still had a high level of egg-laying and peaked in the number of pupae then, whereas egg-laying and the number of pupae per colony of the other treatments began to decline 2,3 weeks earlier. These results indicate that P. dominulus is more opportunistic than P. fuscatus, which may account in part for P. dominulus's success as an introduced species in North America. [source] Maternal size and age affect offspring sex ratio in the solitary egg parasitoid Anaphes nitensENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 1 2007Serena Santolamazza-Carbone Abstract In this study, the effects of maternal age, diet, and size on offspring sex ratio were investigated for the solitary egg parasitoid, Anaphes nitens Girault (Hymenoptera: Mymaridae), both outdoors, during the winter, and inside a climatic chamber under favourable constant conditions. During the winter of 2005,2006, each of seven groups containing 40 1-day-old females was mated and randomly distributed among two treatments: (treatment 1) a droplet of undiluted honey ad libitum + one fresh egg capsule of the snout beetle Gonipterus scutellatus Gyllenhal (Coleoptera: Curculionidae) as host; (treatment 2) drops of water + one fresh egg capsule of G. scutellatus. We recorded the lifetime fecundity, the daily sex allocation, and the lifetime offspring sex ratio to study the existence of a relationship with maternal characteristics. Moreover, we assessed the effect of location (outdoors vs. indoors) and group (groups are representative of early, mid, and late winter) on sex ratio. The most important factor that biased the sex ratio was maternal body size: larger females of both treatments produced more female offspring. As females of A. nitens could gain more advantage than males from body size, larger mothers have a higher fitness return if they produce more daughters. The effect of the treatment was significant: starved females produced more females. Location and group were not significant. Fecundity and sex ratio were age dependent. Old mothers that received honey (treatment 1) had fewer offspring and a more male-biased offspring sex ratio, probably due to reproductive senescence and sperm depletion. Starved females (treatment 2) experienced reproductive decline earlier, perhaps because they invested more energy in maintenance rather than in reproduction. [source] Evaluation of mutant frequencies of chemically induced tumors and normal tissues in ,/cII transgenic miceENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 1 2005Jon C. Mirsalis Abstract Genomic instability has been implicated as an important component in tumor progression. Evaluation of mutant frequencies (MFs) in tumors of transgenic mice containing nontranscribed marker genes should be useful for quantitating mutation rates in tumors as the physiologically inactive transgene provides neither a positive nor a negative selective pressure on the tumor. We have conducted long-term carcinogenicity studies in ,/cII transgenic B6C3F1 mice using a variety of genotoxic and nongenotoxic test agents and have evaluated the mutant frequencies in both tumors and normal tissues from these animals. Mice were administered diethylnitrosamine (DEN) as three intraperitoneal injections of 15 mg/kg; phenobarbital (PB) or oxazepam (OXP) provided ad libitum at 0.1% or 0.25% in the diet, respectively; DEN initiation plus PB in the diet; or urethane (UTH) provided ad libitum at 0.2% in the drinking water. Normal tissues and tumors were isolated at various times over a 2-year period and half of each tissue/tumor was evaluated histopathologically and the other half was evaluated for MF in the cII transgene. Approximately 20 mutants from each of 166 individual tissues (tumor and nontumor) were sequenced to determine whether increases in MF represented unique mutations or were due to clonal expansion. UTH produced significant increases in MF in normal liver and lung. DEN either with or without PB promotion produced significant increases in MF in liver and correction of MF for clonality produced little change in the overall MF in these groups. PB produced a twofold increase in liver MF over controls after 27 weeks of treatment, but a similar increase was not observed with longer dosing times; at later time points, the MF in the PB groups was lower than that of the control group, suggesting that PB is not producing direct DNA damage in the liver. OXP failed to produce an increase in MF over controls, even after 78 weeks of treatment. Selected cases of genomic instability were observed in tumors from all treatments except OXP, with individual liver tumors showing very high MF values even after clonal correction. One rare and interesting finding was noted in a single mouse treated with UTH, where a mammary metastasis had an MF approximately 10-fold greater than the parent tumor, with 75% of the mutations independent, providing strong evidence of genomic instability. There was no clear correlation between tumor phenotype and MF except that pulmonary adenomas generally had higher MFs than normal lung in both genotoxic and nongenotoxic treatment groups. Likewise, there was no correlation between tumor size and MF after correction for clonality. The results presented here demonstrate that individual tumors can show significant genomic instability, with very significant increases in MF that are not attributed to clonal expansion of a single mutant cell. Environ. Mol. Mutagen., 2005. © 2004 Wiley-Liss, Inc. [source] Hematotoxic and hepatotoxic effects of dichlorvos at sublethal dosages in ratsENVIRONMENTAL TOXICOLOGY, Issue 2 2009Ismail Celik Abstract The present study was designed to understand the effects of sublethal concentrations of dichlorvos (DIC) on hematological constituent [red blood corpuscles, white blood corpuscles (WBC), mean cell volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, platelet counts, hemoglobin and hematocrite levels] and serum damage marker enzymes (aspartate aminotransferase, alanin aminotransferase, alkaline phosphatase, and lactate dehydrogenase) in rats at subacute period under laboratory conditions. DIC at dosages of 5 and 10 ppm was administered orally to six male rats ad libitum during the tests for 4 weeks consecutively. According to the results, DIC treatments increased significantly the levels of serum marker enzyme activities, whereas they did not change hematologic constituent except for WBC number treated with both dosages of DIC. The observations presented led us to conclude that the administrations of subacute DIC induced the levels of damage marker enzymes and leukocytosis. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2009. [source] Caloric Restriction Inhibits Seizure Susceptibility in Epileptic EL Mice by Reducing Blood GlucoseEPILEPSIA, Issue 11 2001Amanda E. Greene Summary: ,Purpose: Caloric restriction (CR) involves underfeeding and has long been recognized as a dietary therapy that improves health and increases longevity. In contrast to severe fasting or starvation, CR reduces total food intake without causing nutritional deficiencies. Although fasting has been recognized as an effective antiseizure therapy since the time of the ancient Greeks, the mechanism by which fasting inhibits seizures remains obscure. The influence of CR on seizure susceptibility was investigated at both juvenile (30 days) and adult (70 days) ages in the EL mouse, a genetic model of multifactorial idiopathic epilepsy. Methods: The juvenile EL mice were separated into two groups and fed standard lab chow either ad libitum (control, n = 18) or with a 15% CR diet (treated, n = 17). The adult EL mice were separated into three groups; control (n = 15), 15% CR (n = 6), and 30% CR (n = 3). Body weights, seizure susceptibility, and the levels of blood glucose and ketones (,-hydroxybutyrate) were measured over a 10-week treatment period. Simple linear regression and multiple logistic regression were used to analyze the relations among seizures, glucose, and ketones. Results: CR delayed the onset and reduced the incidence of seizures at both juvenile and adult ages and was devoid of adverse side effects. Furthermore, mild CR (15%) had a greater antiepileptogenic effect than the well-established high-fat ketogenic diet in the juvenile mice. The CR-induced changes in blood glucose levels were predictive of both blood ketone levels and seizure susceptibility. Conclusions: We propose that CR may reduce seizure susceptibility in EL mice by reducing brain glycolytic energy. Our preclinical findings suggest that CR may be an effective antiseizure dietary therapy for human seizure disorders. [source] Effect of paddock vs. stall housing on 24 hour gastric pH within the proximal and ventral equine stomachEQUINE VETERINARY JOURNAL, Issue 4 2008L. HUSTED Summary Reasons for performing study: Stall housing has been suggested as a risk factor for ulcer development in the equine stomach; however, the exact pathogenesis for this has not been established. Objectives: To investigate the effect of 3 environmental situations (grass paddock, stall alone or stall with adjacent companion) on pH in the proximal and the ventral stomach. Methods: Six horses with permanently implanted gastric cannulae were used in a randomised, cross-over, block design. Each horse rotated through each of three 24 h environmental situations. Horses remained on their normal diet (grass hay ad libitum and grain b.i.d.) throughout the study. Intragastric pH was measured continuously for 72 h just inside the lower oesophageal sphincter (proximal stomach) and via a pH probe in the gastric cannula (ventral stomach). Results: Neither proximal nor ventral 24 h gastric pH changed significantly between the 3 environmental situations. Mean hourly proximal gastric pH decreased significantly in the interval from 01.00,09.00 h compared to the interval from 13.00,20.00 h, regardless of environmental situation. Median hourly proximal pH only differed in the interval from 06.00,07.00 h compared to the interval 14.00,19.00 h. Neither mean nor median hourly ventral gastric pH varied significantly with the time of day. Conclusions: The change in housing status used in the current study did not affect acid exposure within either region of the equine stomach. The pH in the ventral stomach was uniformly stable throughout the study, while the proximal pH demonstrated a 24 h circadian pattern. Potential relevance: Since stall housing was not associated with prolonged acid exposure to the proximal stomach, this aspect alone does not explain the increased risk of squamous ulcer development. The circadian rhythm associated with proximal intragastric pH warrants further investigation. [source] Maternal Effort is State Dependent: Energetic Limitation or Regulation?ETHOLOGY, Issue 4 2008Anke Rehling Many small altricial rodents have a postpartum oestrus and are often simultaneously pregnant and lactating. Negative influences of concurrent pregnancy and lactation on both lactational performance and the litter in utero are commonly observed and have been interpreted as resulting from high simultaneous energetic demands of gestation and lactation. We studied these effects in the precocial guinea-pig (Cavia aperea f. porcellus) that, like many altricial rodents, has a postpartum oestrus, but in which the peaks of energy expenditure on lactation and gestation are widely separated. This life history allowed to investigate whether physiological regulation other than by energetic limitations may be responsible for allocation conflicts arising when lactation and gestation overlap. By comparing simultaneously pregnant and lactating females with lactating non-pregnant females, we show that females in the former group nurse less and wean earlier than females of the latter group. In a comparison of litter size, litter mass, and pup mortality of females that had not been lactating during pregnancy with females that had been simultaneously pregnant and lactating, we show that the latter do not reduce investment in the following litter. In our study, energetic constraints on ad libitum fed females are unlikely and we therefore suggest that the results must be explained by regulatory constraints on lactational effort. We point out that this explanation has not been excluded for the effects observed in altricial small mammals. [source] Fatty acids increase the circulating levels of oxidative stress factors in mice with diet-induced obesity via redox changes of albuminFEBS JOURNAL, Issue 15 2007Mayumi Yamato Plasma concentrations of free fatty acids are increased in metabolic syndrome, and the increased fatty acids may cause cellular damage via the induction of oxidative stress. The present study was designed to determine whether the increase in fatty acids can modify the free sulfhydryl group in position 34 of albumin (Cys34) and enhance the redox-cycling activity of the copper,albumin complex in high-fat diet-induced obese mice. The mice were fed with commercial normal diet or high-fat diet and water ad libitum for 3 months. The high-fat diet-fed mice developed obesity, hyperlipemia, and hyperglycemia. The plasma fatty acid/albumin ratio also significantly increased in high-fat diet-fed mice. The increased fatty acid/albumin ratio was associated with conformational changes in albumin and the oxidation of sulfhydryl groups. Moreover, an ascorbic acid radical, an index of redox-cycling activity of the copper,albumin complex, was detected only in the plasma from obese mice, whereas the plasma concentrations of ascorbic acid were not altered. Plasma thiobarbituric acid reactive substances were significantly increased in the high-fat diet group. These results indicate that the increased plasma fatty acids in the high-fat diet group resulted in the activated redox cycling of the copper,albumin complex and excessive lipid peroxidation. [source] Non-lethal predator effects on the performance of a native and an exotic crayfish speciesFRESHWATER BIOLOGY, Issue 12 2005PER NYSTRÖM Summary 1. I tested the hypothesis that the potential for non-lethal effects of predators are more important for overall performance of the fast-growing exotic signal crayfish (Pacifastacus leniusculus Dana) than for the slower growing native noble crayfish (Astacus astacus L.). I further tested if omnivorous crayfish switched to feed on less risky food sources in the presence of predators, a behaviour that could reduce the feeding costs associated with predator avoidance. 2. In a 2 month long outdoor pool experiment, I measured behaviour, survival, cheliped loss, growth, and food consumption in juvenile noble or signal crayfish in pools with either a caged predatory dragonfly larvae (Aeshna sp.), a planktivorous fish that do not feed on crayfish (sunbleak, Leucaspius delineatus Heckel), or predator-free controls. Crayfish had access to multiple food sources: live zooplankton, detritus and periphyton. Frozen chironomid larvae were also supplied ad libitum outside crayfish refuges, simulating food in a risky habitat. 3. Crayfish were mainly active during hours of darkness, with signal crayfish spending significantly more time outside refuges than noble crayfish. The proportion of crayfish outside refuges varied between crayfish species, time and predator treatment, with signal crayfish spending more time in refuges at night in the presence of fish. 4. Survival in noble crayfish was higher than in signal crayfish, and signal crayfish had a higher frequency of lost chelipeds, indicating a high level of intraspecific interactions. Crayfish survival was not affected by the presence of predators. 5. Gut-contents analysis and stable isotope values of carbon (,13C) and nitrogen (,15N) indicated that the two crayfish species had similar food preferences, and that crayfish received most of their energy from feeding on invertebrates (e.g. chironomid larvae), although detritus was the most frequent food item in their guts. Signal crayfish guts were more full than those of noble crayfish, but signal crayfish in pools with fish contained significantly less food and fewer had consumed chironomids compared with predator-free controls. Length increase of signal crayfish (35%) was significantly higher than of noble crayfish (20%), but signal crayfish in pools with fish grew less than in control pools. 6. This short-term study indicates that fish species that do not pose a lethal threat to an organism may indirectly cause reductions in growth by affecting behaviour and feeding. This may occur even though prey are omnivorous and have access to and consume multiple food sources. These non-lethal effects of predators are expected to be particularly important in exotic crayfish species that show a general response to fish, have high individual growth rates, and when their feeding on the most profitable food source is reduced. [source] Do endogenous seasonal cycles of food intake influence foraging behaviour and intake by grazing sheep?FUNCTIONAL ECOLOGY, Issue 5 2000G. R. Iason Abstract 1.,Large herbivores living in temperate regions show different degrees of seasonal biological variation, including voluntary food intake (VFI). The decline of VFI in winter has been hypothesized to be an evolved response to lower food availability or quality, which can act as an internal constraint on food intake. 2.,The hypotheses were tested that (i) animals that have a greater inherent seasonal variation of VFI, measured indoors under ad libitum conditions, would also have a greater seasonal variation in intake and grazing behaviour under field conditions, and (ii) greater seasonal variation in intake and grazing behaviour under field conditions would be expressed at a higher level of food availability. 3.,The intake and grazing behaviour in summer and winter, of three breeds of sheep, were compared at two levels of food availability (at pasture heights of 3·7 and 5·4 cm). The breeds were known to have contrasting degrees of seasonal variation in food intake when fed ad libitum; the VFI of the Shetland (SH) and Scottish Blackface (BF) sheep varies greatly between seasons whereas that of the Dorset Horn (DH) is less seasonally variable. 4.,All three breeds consistently increased their rates of biting and duration of grazing activity in the winter, taking many more smaller bites each day than in the summer, and both digestibility and intake were lower in winter than in summer. 5.,Contrary to expectation, the DH ewes had the highest seasonal difference of dry matter intake at pasture, whereas the SH breed had the lowest variation of intake between seasons. 6.,This experiment provides no evidence that differences between seasons in intake and foraging behaviour in the field vary with the animals' degree of endogenous seasonal variation in VFI. Variation between seasons was consistent at both levels of resource availability, suggesting that it resulted from seasonal changes in food quality (digestibility) rather than biomass availability. It is not easy to extrapolate from laboratory feeding studies, where animals' own physiological constraints apply, to foraging ecology in the field, where constraints imposed by the environment may be more important. [source] Blood pressure and vascular reactivity to endothelin-1, phenylephrine, serotonin, KCl and acetylcholine following chronic alcohol consumption in vitroFUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 3 2001Tijen Utkan Ethanol has been reported to cause hypertension, the mechanism of which is unknown. Therefore, the effect of chronic ethanol consumption on vascular responsiveness and blood pressure was investigated. Systolic blood pressure was recorded weekly by tail-cuff method. Aortic rings from rats fed chow ad libitum or pair-fed liquid diets containing either ethanol (7.2% v/v) or isocaloric carbohydrate for 4 weeks were placed in organ chambers for isometric tension measurement. There was a mild but significant elevation of the systolic blood pressure in the alcohol-fed rats by week 1 compared to baseline measurements and this remained higher. No significant changes in reactivity of rat isolated aortas to phenylephrine, serotonin, endothelin-1 (ET-1) and KCl were seen in chronic ethanol consumption. In addition, the sensitivity (i.e. pD2) of alcohol-fed aortic rings to the vasoconstrictors was also unchanged compared to controls. Chronic ethanol consumption, however, increased relaxation to acetylcholine with increased pD2 values, but did not alter relaxation to sodium nitroprusside, a cyclic guanosine monophosphate (cGMP)-dependent direct smooth muscle dilator. The results indicate that chronic ethanol consumption significantly potentiates endothelium-dependent relaxations in aortic rings, probably through interference with the production and/or the release of nitric oxide (NO) or adaptive alterations in muscarinic receptors on the endothelial cells, and that increased vascular responsiveness to several vasoconstrictors is not a mechanism responsible for the blood pressure elevation in the chronic alcohol consumption in rats. [source] The effect of forage type and level of concentrate supplementation on the performance of spring-calving dairy cows in early lactationGRASS & FORAGE SCIENCE, Issue 3 2002P. Dillon Abstract In 1993 and 1994, 40 cows in early lactation in early spring were assigned randomly to four feeding treatments. One group of cows was kept indoors with access to grass silage ad libitum, plus 6 kg of concentrate daily. The other three groups had access to grass pasture (5,6 h per day in 1993 and 11,12 h per day in 1994) plus grass silage similar to that fed to the previous group while indoors plus 6, 4 or 2 kg of concentrate daily. The average daily allocations of herbage (> 3·5 cm) were 8·5 and 14·0 kg DM cow,1 day,1 in 1993 and 1994 respectively. The treatments were applied for 8 weeks (26 February to 23 April) in 1993, and 7 weeks (11 March to 29 April) in 1994. Cows with access to pasture had lower (P < 0·001) silage dry-matter (DM) intakes and higher (P < 0·001) total forage DM intakes in both years than those kept indoors. This resulted in significantly higher yields of milk, fat, protein and lactose. Similarly, milk protein concentration was higher (P < 0·05 in 1993; P < 0·001 in 1994). There was a significant linear increase in total DM intake in both years with increased concentrate supplementation. In 1993, there was a linear increase in milk (P < 0·01), fat (P < 0·01), protein (P < 0·001) and lactose (P < 0·01) yields with increased concentrate supplementation. In 1994, only milk protein yield (P < 0·05) was increased. Concentrate supplementation had no effect on milk composition or liveweight change. Cows with access to grazed grass had higher liveweight gains (P < 0·05) than those kept indoors in both years. In 1993, increasing the energy intake increased the processing qualities of the milk produced. The results showed that access to grass pasture resulted in higher milk production, in reduced silage requirement and in reduced level of concentrate supplementation required for a given level of milk production with spring-calving cows in early lactation compared with those kept indoors. [source] Body protein does not vary despite seasonal changes in fat in the White Stork Ciconia ciconiaIBIS, Issue 1 2002Delphine Michard-Picamelot To understand how a large soaring bird, the White Stork Ciconia ciconia, copes with energy constraints, we compared changes in body mass in 14 captive adult storks with the body composition of 12 free-ranging adult storks found dead from accidents. The captive storks, already in an enclosure for several years, were fed ad libitum. They were weighed daily for 1.5,3.5 years using an automatic device. The bodies of the accidentally killed storks were analysed to determine total water, lipid, protein and ash contents, and to assess the biochemical composition of certain organs. Females were on average 20% lighter and 24% smaller than males, but the body mass of the sexes varied in parallel throughout the year. Body mass peaked in December and January (25,30% above minimal body mass), due essentially to large fat stores in subcutaneous and abdominal adipose tissues. Body mass and body lipid rapidly decreased from February to June, whether the storks reared chicks successfully or not, and remained minimal for a few days into July. In contrast to birds using flapping flight, no variation in body protein or pectoral muscle protein was observed while breeding, even though the moult occurred then, nor in August, before the time when wild storks migrate. An endogenous regulation of body fuels is discussed. [source] Effect of ipriflavone on pain due to recent osteoporotic vertebral crush fractureINTERNATIONAL JOURNAL OF RHEUMATIC DISEASES, Issue 1 2002Mohammad M. Rahman Abstract Aim:,Ipriflavone conserves bone mass in postmenopausal osteoporosis. Salmon calcitonin and alendronate, two other anti-resorptive drugs, have been found to have analgesic effects in osteoporotic acute vertebral fracture. This study aimed to determine if ipriflavone also possesses such an effect. Methods:,Thirty-two women with recent osteoporotic vertebral fractures were randomly assigned to ipriflavone treatment or placebo groups. Ipriflavone was given at the dose of 200 mg three times a day. Non-steroidal anti-inflammatory drugs were given ad libitum in both groups. Calcium carbonate (1 g daily) was administered to all subjects. Intensity of pain at rest, on movement and on pressure, pain rating on a 10-point visual analogue scale, degree of mobility impairment, and supplementary analgesic were assessed at the end of a 3-month period in both groups to assess the analgesic effect of ipriflavone. Results:,Fourteen subjects in the ipriflavone group and 12 in the placebo group completed the trial. After 3 months, all pain variables had decreased significantly in both groups. Intensity of pain at rest and on pressure and supplementary analgesic use were significantly lower in the ipriflavone group compared to the placebo group. Conclusion:,The study shows that ipriflavone has an analgesic adjuvant effect in acute osteoporotic vertebral fracture. [source] Serum insulin-like growth factor-1 concentration in pigs divergently selected for daily food intake or lean growth rateJOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 4 2003N. D. Cameron Summary Divergent selection over seven generations for daily food intake (DFI) and for two lean growth rate (LGA and LGS) selection objectives in pigs produced correlated responses in serum insulin-like growth factor-1 (IGF-1) concentration. The LGA and LGS selection objectives were for lean growth, but with performance testing on ad libitum (LGA) or on restricted (LGS) feeding regimes. There were 342 animals in the study, with an average of 46 pigs in each selection line and 72 pigs in the control line. All animals were performance-tested from 30 to 90 kg on an ad libitum feeding regime. Selection on DFI increased IGF-1 at 6 weeks of age (158 versus 104 ,g/l, SED 21; control 136 ,g/l) and selection for high LGA increased IGF-1 at 30 kg liveweight (202 versus 161 ,g/l, SED 14; control 185 ,g/l). At 6 weeks of age and at 30 kg of weight, there was no response in IGF-1 with selection on LGS (128 versus 129 and 167 versus 153 ,g/l, respectively) suggesting that IGF-1 may not be a reliable physiological predictor of genetic merit for such a selection objective, which combined rate and efficiency of lean growth. IGF-1 measured immediately prior to the start of performance test may be useful in determining which animals to performance test for a lean growth selection objective, whereas IGF-1 measured at 6 weeks of age may be a useful physiological predictor of genetic merit for daily food intake during performance test. Zusammenfassung Serumkonzentrationen des insulinähnlichen Wachstumsfaktors-1 bei Schweinen, die entweder auf tägliche Futteraufnahme oder auf hohe Wachstumsrate für Magerfleischanteil selektiert wurden Die Selektion von Schweinen über sieben Generationen einerseits auf tägliche Futteraufnahme (DFI) und andererseits auf zwei Wachstumsraten für Magerfleischanteil (LGA, ad-libitum -Fütterung; LGS, rationierte Fütterung) ergab korrelierende Konzentrationen am insulinähnlichen Wachstumsfaktor (IGF-1). An der Studie waren 342 Tiere mit einer durchschnittlichen Tierzahl von 46 Schweinen pro Selektionsgruppe und 72 Schweinen als Kontrollgruppe beteiligt. Alle Tiere wurden zwischen 30 und 90 kg bei der ad-libitum Fütterung leistungsgeprüft. Die Selektion auf tägliche Futteraufnahme (DFI) erhöhte die IGF-1 Konzentrationen in der 6. Lebenswoche von 104 ,g/l auf 158 ,g/l (Kontrollgruppe 136 ,g/l) und die Selektion auf LGA bei der ad-libitum -Fütterung bei einem Lebendgewicht von 30 kg von 161 ,g/l auf 202 ,g/l (Kontrollgruppe 185 ,g/l). In der 6. Lebenswoche und bei 30 kg Lebendgewicht gab es keinen Anstieg der IGF-1 Konzentrationen in der Selektionsgruppe LGS mit rationierter Fütterung (128 ,g/l bzw. 129 ,fg/l in der 6. Lebenswoche; 167 ,g/l bzw. 153 ,g/l bei 30 kg),was darauf hinweisen könnte, dass IGF-1 wahrscheinlich kein verlässlicher, physiologischer Marker für den genetischen Erfolg für ein solches Selektionsziel, welches die Wachstumsrate und die Effizienz beim Magerfleischwachstum kombiniert, darstellt. Die direkt vor Prüfungsbeginn ermittelten IGF-1 Konzentrationen könnten bei der Auswahl der Tiere, die an einer Leistungsprüfung für die Wachstumsrate des Magerfleischanteils als Selektionsziel herangezogen werden sollten, hilfreich sein. Die IGF-1 Konzentrationen, die in der 6. Lebenswoche gemessen werden, sind wahrscheinlich ein hilfreicher physiologischer Marker für den genetischen Erfolg für DFI während einer Leistungsprüfung. [source] Re-induction of obese body weight occurs more rapidly and at lower caloric intake in beaglesJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 3 2010D. Nagaoka Summary For the purpose of investigating the mechanism of obesity-induction/re-induction including weight-cycling in beagles, a study was conducted using commercially available dog food combined with human food to mimic at home-snacking and diet-supplementation behaviours. Adult female beagles, which had free access to water and exercise, were used (n = 9). All dogs were initially offered two times their daily calculated number of calories using a dry extruded diet plus blend of canola and soybean oils and allowed to eat ad libitum. After 3 weeks, Pecan shortbread cookies were added to the diet mixture. Obesity was induced during a 19-week period with 1875,2250 kcal/day consumed, on average, during this period. The dogs were then subjected to a weight-loss regimen while consuming 490,730 kcal/day. After weight loss, a similar degree of obesity was re-induced for 17 weeks even though dogs consumed only 1125,1250 kcal/day. Body weight, body condition scores, kcal consumption and food efficiency were recorded. Results indicated that less time and fewer kcal were required to re-induce the same degree of obesity compared with the initial obesity induction. Human snack foods appeared to stimulate appetite and thus contribute to the obese state. Food efficiency was also increased during the obesity-reinduction period compared with the induction period. This information may help pet owners better understand the need to limit table scraps and human-type food snacks in dogs prone to obesity as well as weight maintenance after weight loss. [source] Metabolic and luteal function in winter-calving Spanish beef cows as affected by calf management and breedJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 3 2010J. Álvarez-Rodríguez Summary This experiment aimed at evaluating the effect of calf management and breed on the metabolic and luteal function of post-partum beef cows fed at maintenance. Fifty multiparous cows, 22 Parda de Montaña (PA) and 28 Pirenaica (PI), were assigned to either suckling once-daily for 30 min (RESTR) or ad libitum (ADLIB) from the day after calving. Blood samples were collected to analyse metabolites [non-esterified fatty acids (NEFA), ,-hydroxybutyrate, total protein and urea)], insulin-like growth factor-I (IGF-I) and progesterone (P4) at different intervals. Cows from RESTR maintained their live-weight (LW) over the first 3 months post-partum, whereas ADLIB cows lost nearly 4% LW. Both genotypes showed similar LW gains during this period (p > 0.10). Calf daily gains were lower in RESTR than in ADLIB treatment (p < 0.05), but similar across breeds (p > 0.10). Milk and lactose production were lower in RESTR cows than in ADLIB (p < 0.05). Milk and protein yield were greater in PA than in PI breed (p < 0.05). Serum NEFA, total protein and urea were higher in PI cows suckling ADLIB than in the rest (p < 0.05). Cows from PI breed had greater NEFA values than PA ones on the first week post-partum (p < 0.001). Circulating IGF-I was not affected by suckling frequency, breed nor their interaction (p > 0.10). Suckling frequency, but not breed, affected the interval from calving to first ovulation (p < 0.001), being shorter in RESTR than in ADLIB cows. In conclusion, the ad libitum suckling practice improved cow milk yield and offspring gain compared to once-daily suckling for 30 min from the day after calving, at the expense of impairing the onset of cyclicity. The effect of calf management was confounded with breed on the studied blood biochemical constituents, but any of these metabolites influenced the role of endocrine IGF-I in these genotypes. [source] Effect of different liquid cultures of live yeast strains on performance, ruminal fermentation and microbial protein synthesis in lambsJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 6 2008M. K. Tripathi Summary Three yeast strains, Kluyveromyces marximanus NRRL-3234 (KM), Saccharomyces cerevisiae NCDC-42 (SC) and Saccharomyces uvarum ATCC-9080 (SU), and a mixed culture (1:1:1 ratio) were evaluated for their value as probiotics in lamb feeding in two experiment. In experiment I and II, 20 and 30 pre-weaner lambs were fed for 63 and 60 days in two and three equal groups respectively. All lambs were offered ad libitum a creep mixture and Zizyphus nummularia leaves, and yeasts were dosed orally. In experiment I, one group received no yeast, the other of the mixed culture (1.5,2 × 1010 live cells/ml). In experiment II, yeast cultivation was modified yielding 1.5,2 × 1013 live cells/ml. Lambs of the three experimental groups received 1 ml/kg live weight of one of the individual yeasts. Feed intake did not differ among groups of both experiments with the exception of SC-supplemented lambs in experiment II which showed a trend to higher intakes per kg metabolic body weight and in percentage of body weight when compared with KM- and SU-supplemented lambs. Supplementation of the mixed yeast culture had no effect on intakes of digestible crude protein and metabolisable energy, nutrient digestibility, nitrogen balance and rumen fermentation characteristics (pH, ammonia, volatile fatty acid concentration, protozoa count) and urinary allantoin as an indicator of microbial protein synthesis. The same was true for comparisons in experiment II except ciliate protozoa counts, which showed a trend to be the highest with SU and the lowest with SC. The results of present study show that the response of lambs to supplemented live yeast cultures is inconsistent, as it lacked to have an effect in the present study, and that differences among strains were small, even when supplemented at a much higher live cell count. [source] Effect of ovariectomy and ad libitum feeding on body composition, thyroid status, ghrelin and leptin plasma concentrations in female dogs,JOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 1-2 2006I. Jeusette Summary The objective of this study was to evaluate the effects of ovariectomy (i) and ad libitum feeding (ii) on energy intake, body weight (BW), body composition, thyroid status, leptin and ghrelin plasma concentrations. Four young adult female Beagle dogs were fed a maintenance diet for 6 weeks prior to ovariectomy, then 6 months after. Food allowance was adjusted in order to maintain optimal BW. Then, a diet slightly higher in energy concentration was fed ad libitum for 4 months. The maintenance diet was then fed ad libitum for one additional month. The maintenance of optimal BW after ovariectomy required a significant decrease in energy allowance. No increase in fat mass was observed. Ghrelin concentration remained unchanged. During the first month of ad libitum feeding, plasma ghrelin concentration and energy intake increased, then they decreased. Mean BW, plasma leptin, thyrotropin (TSH), total triiodothyronine (TT3) and total thyroxine (TT4) concentrations significantly increased over the study. The BW increase was exclusively due to an increase in body fat. In conclusion, energy allowance should be strictly controlled in spayed female dogs. The results suggest that in dogs, thyroid hormones, leptin and ghrelin concentrations change in response to a positive energy balance in an attempt to limit weight gain. However, the significant weight gain shows that this goal was not achieved. [source] Influence of crop residue ration supplementation on the attainment of puberty and postpartum reproductive activities of Red Sokoto goatsJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 1-2 2005B. S. Malau-Aduli Summary The general objective of this study was to come up with an appropriate, affordable and locally available crop residue supplementation package that would enhance reproductive performance in small ruminants. Specifically, 28 Red Sokoto weaner does between 3 and 4 months of age weighing between 2 and 3 kg were used in the first experiment to determine the influence of crop residue supplementation on age and weight at puberty as determined by blood progesterone levels. In the second experiment, another 28 adult does (,2 years old) of the same breed in the same flock with lactation numbers between 1 and 3 were used to determine the length of postpartum acyclic period. In both experiments, a 3 × 2 factorial experimental design comprising three dietary supplements (A, B, C) at two feeding levels (1% and 2% of body weight) fed in addition to a basal diet of Digitaria smutsii hay and natural pasture ad libitum with an unsupplemented negative control group (D) and four goats per treatment was utilized. In ration A, a conventional concentrate supplement consisting of maize, wheat offal, cottonseed cake and bonemeal was utilized; in rations B and C, the supplement consisted of guinea-corn bran, cowpea husk and groundnut haulms; and maize offal, groundnut shells and groundnut haulms respectively. Unsupplemented (ration D) weaner does reached puberty at a later age and had lighter body weights than all the others. Weaner does on ration 2A (concentrate fed at 2% of body weight) attained puberty at the earliest age and heaviest body weight, although the age at puberty was not significantly different from those on rations 1A (concentrate fed at 1% body weight), 1C and 2C. Blood progesterone profiles before and after puberty ranged from 0.05 to 9.0 ng/ml, respectively, and was highest in does fed rations A and C and least in the unsupplemented does. The mean interval between kidding and initiation of ovarian activity was 54.28 ± 17.61 days and the mean interval between kidding and conception was 63.04 ± 25.34 days. Only 25% of the unsupplemented does conceived again during the period under study compared with 100% in rations 1A, 2A, 1C and 2C; 75% in ration 2B and 50% in ration 1B. It was concluded that implementation of supplementary feeding in the dry season improves reproductive performance in the Red Sokoto doe. Furthermore, ration C, a crop residue-based ration, was a suitable dry season supplementation alternative to the expensive conventional concentrate ration for the smallholder goat farmer in the subhumid tropics of Nigeria. [source] Modulation of Na+ transport across isolated rumen epithelium by short-chain fatty acids in hay- and concentrate-fed sheepJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 11-12 2003S. K. Uppal Summary The effect of increasing concentrations of short-chain fatty acids [SCFA; mixture of the Na+ salts of acetic acid (62.5%), propionic acid (25.0%) and of butyric acid (12.5%)] on Na+ transport of sheep rumen epithelium was studied in vitro. The conventional Ussing chamber method was used for measuring Na+ transport rates (22Na+), short-circuit current (Isc) and tissue conductance (GT) of isolated rumen epithelium. SCFA in the buffer solution on the mucosal side caused a linear increase of Jnet Na+ from 1.14, to 1.22, 1.78 and 2.50 ,eq/cm2/h in hay-fed sheep at 0, 15, 40 and 80 mmol/l SCFA, respectively. In a second study, the effect of higher SCFA concentrations [0 (control), 80, 100 and 120 mmol/l] was investigated with epithelia from two groups of sheep. One group was subjected to hay ad libitum, whereas the other received concentrate feed (800 g/day in equal portions at 7.00 am and 3.00 pm) and hay ad libitum. Epithelia from concentrate-fed sheep again showed a significant (p < 0.05) and linear increase in Jnet Na+ at 80, 100 and 120 mmol/l. However, in hay-fed sheep, the difference in increase among 80, 100 and 120 mmol/l SCFA was not significant, indicating that, above 80 mmol/l SCFA Jms and Jnet exhibit saturation. Moreover, Na+ fluxes (Jms and Jnet) were generally higher in concentrate-fed than in hay-fed sheep at all SCFA concentrations and significant differences were observed at 100 and 120 mmol/l SCFA. The obtained results confirm the effect of SCFA on Na+ transport and are in agreement with studies regarding feeding regimes and electrolyte transport in the rumen. The important new observation is the increase of Na+ transport in concentrate-fed sheep even at high concentrations of SCFA (100 and 120 mmol/l). The enhanced activity of the Na+/H+ exchanger at these SCFA concentrations supports the assumption that the capacity for regulating the intracellular pH by extrusion of protons is increased, suggesting an adaptation in concentrate-fed sheep. This adaptation could prevent possible disturbances of epithelial functions (transport and barrier) under conditions of increased SCFA absorption. [source] The effect of short chain fatty acids on calcium flux rates across isolated rumen epithelium of hay-fed and concentrate-fed sheepJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 1-2 2003S. K. Uppal Summary The present in vitro experiment was conducted to study the effect of two concentrations of short chain fatty acids [SCFA: 0 (control), 40 and 100 mmol/l in the buffer solution on mucosal side] on calcium ion (Ca2+) transport across the isolated rumen epithelium of two groups of sheep. One group was subjected to hay ad libitum, whereas the other to concentrate feed (800 g per day in equal portion at 7.00 and 15.00 hours and hay ad lib). The conventional Ussing chamber method was used for measuring the Ca2+ transport rates (45Ca), short-circuit current (Isc) and tissue conductance (GT) of isolated rumen epithelium. The SCFA significantly increased Isc of the epithelia of concentrate-fed sheep. In both hay- and concentrate-fed animals, 45Ca flux rates showed an almost linear increase in net flux rate () with rising concentrations of SCFA, as a result of a combined effect of a large increase in mucosal-to-serosal flux rates () and an almost linear, but small, decrease in serosal-to-mucosal flux rate (). In concentrate-fed sheep and were significantly higher in tissues incubated with SCFA compared with hay-fed animals. The well-known adaptable morphological and functional changes in the rumen epithelium attributable to concentrate feeding obviously include Ca2+ transport; such feeding therefore may be considered as a possible prophylactic measure in the prevention of milk fever. [source] Effect of protein : energy ratio in milk replacers on growth performance of goat kidsJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 5-6 2002K-H. YEOM Two separate experiments were carried out to establish the effects of the protein : energy ratio in milk replacers on growth performance, plasma lipid concentrations and fatty acid composition in adipose tissue of male goat kids. In the first experiment there were 211 3-day- old goat kids and in the second experiment there were 121 kids aged 3,7 days. The animals were fed ad libitum for a period of 4 weeks on milk replacers containing either 11.5 or 9.5 g crude protein/MJ metabolizable energy. In essence, protein was exchanged with fat on a weight basis. Milk concentrations were increased from 160 to 190 g/l in experiment 1, from 150 to 180 g/l in experiment 2. There were significant increases in body weight and feed intake when the milk replacer with high protein : energy ratio was fed. Group mean average daily weight gain was 168 and 203 g for the groups with low and high dietary protein : energy ratio in experiment 1; for experiment 2 the values were 139 and 160 g. Average dry matter intake was 18 and 14% higher for the diet with high protein : energy ratio in experiments 1 and 2, respectively. There was no change in either feed conversion (feed : gain ratio) or energy conversion (weight gain : energy intake ratio). There were no consistent diet effects on plasma lipid concentrations. Dietary fatty acid composition was reflected by that of adipose tissue. The milk replacer with high protein : energy ratio produced a small increase in the contents of myristic and palmitic acid in adipose tissue. [source] The assessment of the frequency of chews during rumination enables an estimation of rumination activity in hay-fed sheepJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 3-4 2002M. KASKE The objective was to assess rumination behaviour and, more specifically, the intra-individual and inter-individual variation of the frequency of chews during rumination (per min) in five Blackhead sheep fed hay at a level of 100% maintenance (experimental period [EP] I), 50% maintenance (EP II) and ad libitum (EP III). Animals ruminated in EP II less (416 min/day) than in EP I and III (558 and 592 min/day, respectively). Mean inter-individual coefficents of variation (CV) of frequency (defined as number of chews/duration of chewing per cycle) were 12.5%, mean intra-individual CV were 2.5%. The respective CVs for the duration of rumination per day were 8.1 and 9.7%, respectively. The level of intake influenced the frequency of chews significantly. It is concluded that the frequency of chews has to be considered in studies investigating chewing behaviour of ruminants. Under the experimental conditions investigated, number of chews during rumination per day could be estimated by the frequency of chewing with nearly the same precision as by using the duration of rumination per day. [source] Metabolic changes during the perinatal period in dairy sheep in relation to level of nutrition and breed.JOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 3-4 2000Summary The effect of level of nutrition during pregnancy was investigated on various plasma parameters, on energy intake, body weight, energy balance and milk yield, after parturition in two Greek dairy breeds. Thirteen Chios (CH) and 17 Karagouniko (K) pregnant ewes were assigned to groups A and B, which received 110% of their energy requirements for maintenance plus pregnancy for two foetuses and 90% of their maintenance energy requirements, respectively. After parturition all ewes were fed ad libitum. Body weights of group A and K ewes were higher (p 0.05) compared with group B and CH ewes, during lactation, although daily energy intakes tended to be greater in group B than in A ewes, during the first 3 weeks and in CH than K ewes (p 0.05), after the second week post-partum. Total mean milk production was 114 ± 11 l and 82 ± 10 l for groups A and B (p 0.05) and 120 ± 12 l and 70 ± 7 l for CH and K ewes (p 0.001), respectively. Positive energy balance appeared after the day 15 and 7 of lactation, for groups A and B ewes and after the day 15 and 5 of lactation, for CH and K ewes, respectively. The group B and K ewes tended to have higher mean plasma glucose concentrations than group A and CH ewes, during early lactation. There were no significant differences in free fatty acids, ,-hydroxybutyric acid, insulin and T4 concentrations between A and B ewes. CH had higher free fatty acids (p 0.05) and ,-hydroxybutyric acid (p 0.05), and lower T4 (p 0.01) and insulin (p 0.05) concentrations than K ewes. It was concluded that under-nutrition during pregnancy results in low milk yields of ewes fed ad libitum in early lactation, due to the poor development of the udder during late gestation. [source] Cobalt requirement of beef cattle , feed intake and growth at different levels of cobalt supplyJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 3 2000F. J. Schwarz Summary In a study using a total of 36 German Simmental beef bulls weighing between 236 kg and about 620 kg the question of what constitutes an adequate Co supply was investigated with reference to the performance criteria growth, feed intake, energy intake, nutrient intake and carcass criteria. The bulls received a diet of corn silage ad libitum and 2.5 kg concentrate for a period of 280 days. Ten rations (R) with graduated Co supplements were fed with mean concentrations of 0.07 (R1), 0.09 (R2), 0.11 (R3), 0.15 (R4), 0.18 (R5), 0.26 (R6), 0.33 (R7), 0.42 (R8), 0.59 (R9) and 0.69 (R10) mg Co per kg dry matter (DM) intake. The Co supplement was added as CoSO47H2O. The diets with no or low Co supplementation produced either distinctly lower daily gains of 1045g (R1) and 1130g (R2) or lower daily gains of about 1260 g (R3, R4) than rations R5,R10, where daily gains averaged 1340 g. The mean daily feed intake per animal was also significantly or marginally affected with values of 6.0 kg DM (R1) rising to 7.7 kg DM (R2,R4) versus 7.9 kg DM on average (R5,R10). Calculations using the broken line model and the quadratic model show that the optimal Co supply for maximum growth is 0.12 mg/kg dietary DM and for maximum feed intake, 0.16,0.18 mg Co/kg dietary DM. After taking further biochemical criteria into account (Stangl et al. 2000), a level of 0.20 mg/kg dietary DM is recommended as an adequate Co supply for growing cattle. [source] Uropygial gland size correlates with feather holes, body condition and wingbar size in the house sparrow Passer domesticusJOURNAL OF AVIAN BIOLOGY, Issue 3 2010Gregorio Moreno-Rueda The uropygial gland is an organ exclusive of birds that secretes an oily substance, the uropygial secretion, the functions of which are still debated. One of the proposed hypothesis is its possible action against chewing lice (order Phthiraptera), a group of avian ectoparasites that feed on feathers, causing different types of harm. However, this hypothesis lacks support. The present study analyses the relationship between uropygial gland size and the number of feather holes (which is correlated with the load of chewing lice) in the house sparrow Passer domesticus. Moreover, the relationship between the uropygial gland size and different aspects of sparrow health (body condition, immunocompetence and haematocrit), as well as sexually selected traits in males (badge and wingbar size), is tested. The results show a negative correlation between uropygial gland size and number of feather holes, a result found both years of the study. This result supports the hypothesis that uropygial secretion is used against chewing lice. Uropygial gland size also correlated positively with body condition (residuals of body mass relative to tarsus length) and immunocompetence, being therefore related to bird health. After a year in captivity, with resources provided ad libitum, no correlation was found between individual uropygial gland size and body condition or haematocrit, perhaps because the negative effect that chewing lice exert on bird health was offset by captivity conditions. Uropygial gland size was not correlated with badge size, but it was correlated with wingbar size, which furthermore supports the contention that this sexually selected signal acts as an indicator of lice resistance in the house sparrow. In summary, this study supports the idea of a positive relationship between uropygial gland and bird health in the house sparrow, the gland secretion affording resistance against chewing lice. [source] Influence of subacute treatment of some plant growth regulators on serum marker enzymes and erythrocyte and tissue antioxidant defense and lipid peroxidation in ratsJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 4 2006Ismail Celik Abstract This study aims to investigate the effects of the plant growth regulators (PGRs) (2,3,5-triiodobenzoic acid (TIBA), Naphthaleneacetic acid (NAA), and 2,4-dichlorofenoxyacetic acid (2,4-D)) on serum marker enzymes (aspartate aminotransferase (AST), alanin aminotransferase (ALT), creatine phosphokinase (CPK), and lactate dehydrogenase (LDH)), antioxidant defense systems (reduced glutathione (GSH), glutathione reductase (GR), superoxide dismutase (SOD), glutathione-S-transferase (GST), and catalase (CAT)), and lipid peroxidation content (malondialdehyde = MDA) in various tissues of rats. 50 and 100 ppm of PGRs as drinking water were administered orally to rats (Sprague,Dawley albino) ad libitum for 25 days continuously. The PGRs treatment caused different effects on the serum marker enzymes, antioxidant defense systems, and the MDA content in experimented rats compared to controls. Results showed that TIBA caused a significant decrease in serum AST activity with both the dosage whereas serum CPK was significantly increased with 100 ppm dosage of TIBA. Meanwhile, serum AST, CPK, and LDH activities were significantly increased with both dosage of NAA and 2,4-D. The lipid peroxidation end-product MDA significantly increased in the all tissues treated with both dosages of PGRs without any change in the brain and erythrocyte of rats treated with both the dosages of 2,4-D. The GSH depletion in the kidney and brain tissues of rats treated with both dosages of PGRs was found to be significant. Furthermore, the GSH depletion in the erythrocyte of rats treated with both dosages of PGRs except 50 ppm dosage of 2,4-D was significant too. Also, the GSH level in the liver was significantly depleted with 50 ppm of 2,4-D and NAA, whereas the GSH depletion in the same tissue did not significantly change with the treatment. The activity of antioxidant enzymes was also seriously affected by PGRs; SOD significantly decreased in the liver, heart, kidney, and brain of rats treated with both dosages of NAA, whereas the SOD activity in the erythrocytes, liver, and heart was either significantly decreased or not changed with two doses of 2,4-D and TIBA. Although the CAT activity significantly increased in the erythrocyte and brain of rats treated with both doses of PGRs, it was not changed in the liver, heart, and kidney. Meanwhile, the ancillary enzyme GR activity significantly increased in the brain, heart, and liver but decreased in the erythrocyte and kidney of rats treated with both doses of PGRs. The drug-metabolizing enzyme GST activity significantly increased in the heart and kidney but decreased in the brain and erythrocytes of rats treated with both dosages of PGRs. As a conclusion, the results indicate that PGRs might affect antioxidant potential enzymes, the activity of hepatic damage enzymes, and lipid peroxidation dose independently. Also, the rats resisted to oxidative stress via antioxidant mechanism but the antioxidant mechanism could not prevent the increases in lipid peroxidation in rat's tissues. These data, along with the determined changes, suggest that PGRs produced substantial systemic organ toxicity in the erythrocyte, liver, brain, heart, and kidney during the period of a 25-day subacute exposure. © 2006 Wiley Periodicals, Inc. J Biochem Mol Toxicol 20:174,182, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20134 [source] Collagen Metabolism Is Markedly Altered in the Hypertrophic Cartilage of Growth Plates from Rats with Growth Impairment Secondary to Chronic Renal FailureJOURNAL OF BONE AND MINERAL RESEARCH, Issue 3 2001Jesús Álvarez Abstract Skeletal growth depends on growth plate cartilage activity, in which matrix synthesis by chondrocytes is one of the major processes contributing to the final length of a bone. On this basis, the present work was undertaken to ascertain if growth impairment secondary to chronic renal insufficiency is associated with disturbances of the extracellular matrix (ECM) of the growth plate. By combining stereological and in situ hybridization techniques, we examined the expression patterns of types II and X collagens and collagenase-3 in tibial growth plates of rats made uremic by subtotal nephrectomy (NX) in comparison with those of sham-operated rats fed ad libitum (SAL) and sham-operated rats pair-fed with NX (SPF). NX rats were severely uremic, as shown by markedly elevated serum concentrations of urea nitrogen, and growth retarded, as shown by significantly decreased longitudinal bone growth rates. NX rats showed disturbances in the normal pattern of chondrocyte differentiation and in the rates and degree of substitution of hypertrophic cartilage with bone, which resulted in accumulation of cartilage at the hypertrophic zone. These changes were associated with an overall decrease in the expression of types II and X collagens, which was especially marked in the abnormally extended zone of the hypertrophic cartilage. Unlike collagen, the expression of collagenase-3 was not disturbed severely. Electron microscopic analysis proved that changes in gene expression were coupled to alterations in the mineralization as well as in the collagen fibril architecture at the hypertrophic cartilage. Because the composition and structure of the ECM have a critical role in regulating the behavior of the growth plate chondrocytes, results obtained are consistent with the hypothesis that alteration of collagen metabolism in these cells could be a key process underlying growth retardation in uremia. [source] | ||||||||||||||||||||||||||||||||||