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Weanling Rats (weanling + rat)
Selected AbstractsNeonatal alcohol exposure impairs acquisition of eyeblink conditioned responses during discrimination learning and reversal in weanling ratsDEVELOPMENTAL PSYCHOBIOLOGY, Issue 3 2007Kevin L. Brown Abstract Discrimination and reversal of the classically conditioned eyeblink response depends on cerebellar,brainstem interactions with the hippocampus. Neonatal "binge" exposure to alcohol at doses of 5 g/kg/day or more has been shown to impair single-cue eyeblink conditioning in both weanling and adult rats. The present study exposed neonatal rats to acute alcohol intubations across different developmental periods (postnatal day [PND] 4-9 or PND7-9) and tested them from PND26-31 on discriminative classical eyeblink conditioning and reversal. A high dose of alcohol (5 g/kg/day) dramatically impaired conditioning relative to controls when exposure occurred over PND4-9, but produced mild or no impairments when delivered over PND7-9. These findings support previous claims that developmental exposure period plays a critical role in determining the deleterious effects of alcohol on the developing brain. A lower dose of alcohol (4 g/kg/day) delivered from PND4-9,lower than has previously been shown to affect single-cue eyeblink conditioning,also produced deficits on the discrimination task, suggesting that discrimination learning and acquisition of responding to CS+ during reversal may be especially sensitive behavioral indicators of alcohol-induced brain damage in this rat model. © 2007 Wiley Periodicals, Inc. Dev Psychobiol 49: 243,257, 2007. [source] The lowering effect of high copper intake on selenium retention in weanling rats depends on the selenium concentration of the dietJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 1-2 2001S. Yu The question addressed was whether the influence of dietary copper concentration on selenium metabolism depends on the amount of selenium in the diet. Weanling, male rats were fed purified diets containing either 1 (low), 4 (normal) or 42 (high) mg Cu/kg diet and either 0.03 (low), 0.05 (normal) or 1.0 (high) mg Se/kg diet in a 32 factorial design. Extra copper was added to the diets in the form of CuSO4,·,5H2O and selenium as Na2SeO3,·,5H2O. In rats fed either the low or normal amounts of selenium, higher intakes of copper decreased the apparent intestinal selenium absorption and increased urinary selenium excretion. The effects of copper on selenium absorption, excretion and retention were not seen in rats fed the high-selenium diets. An increase in dietary copper concentrations elevated selenium concentrations in the liver and kidneys, but slightly lowered those in the spleen of rats that were fed the diets with the normal level of selenium. In rats that were fed the diets with either low or high selenium concentration, copper intake had no effect on organ selenium concentrations. Glutathione peroxidase activity in erythrocytes was raised by feeding the diets which contained either normal or high copper content instead of those that were low in copper. It is concluded that the amount of selenium in the diet determines whether or not an increase in dietary copper concentration affects selenium metabolism. [source] Nutritional Quality of Drum-processed and Extruded Composite Supplementary FoodsJOURNAL OF FOOD SCIENCE, Issue 2 2005Theobald C.E. Mosha ABSTRACT: This study was conducted to evaluate the nutritional quality of ready-to-eat composite foods intended for supplementary feeding of preschool age children in Tanzania. Four supplementary foods, namely, corn-bean-sardine meal (CBSM), bean meal (BM), sorghum-bean-sardine meal (SBSM), and rice-bean-sardine meal (RBSM) were formulated according to the FAO/WHO/UNU guidelines. The food mixtures were extruded, drum-processed, and cooked conventionally in the traditional way. Cooking doneness was evaluated by percent starch gelatinization and residual urease activity; biological qualities,true protein digestibility and growth performance,were evaluated using Sprague Dawley weanling rats. Efficiency in destroying phytohemagglutinins and the antinutritional factors, trypsin, chymotrypsin, and ,-amylase inhibitors, were also evaluated. Results of the study showed that starch gelatinization and residual urease activity were not significantly different (P > 0.05) between the extruded and drum-processed diets. Relative to conventional cooking, starch gelatinization was 95% to 100% in extruded and 90% to 100% in drum-processed products. Inactivation of urease activity ranged from 93% to 100% in extruded and 83% to 100% in drum-processed diets. The true protein digestibilities were significantly (P, 0.05) higher when extruded foods, compared with drum-processed and conventionally cooked foods, were fed to experimental animals. Animals fed extruded products gained more weight relative to those fed drum-processed and conventionally cooked foods. Destruction of phytohemagglutinins ranged between 91% to 97% in extruded and between 90% to 95% in the conventionally cooked and drum-processed foods. Extrusion, drum processing, and conventional cooking also resulted in significant destruction of the antinutritional factors trypsin, chymotrypsin, and a-amylase inhibitors. These results suggest that extrusion and drum processing of cereal-bean-sardine composite foods result in products meeting the required nutritional quality. [source] Nutritional study of raw and popped seed proteins of Amaranthus caudatus L and Amaranthuscruentus LJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 10 2004Tamer H Gamel Abstract The nutritional value of raw and popped (similar to popcorn preparation) seed proteins of two amaranth species, Amaranthus caudatus L and A cruentus L, was investigated. After popping, the true protein content in A caudatus and A cruentus decreased by 9 and 13% respectively. Among the amino acids, the loss of tyrosine due to the popping effect was the highest, followed by phenylalanine and methionine. Leucine was the first limiting amino acid in the raw samples, followed by lysine, while the reverse order was observed in the popped samples. The in vivo protein quality of raw and popped seeds was tested with male weanling rats and compared with wheat flour and casein samples. There was no difference between the in vivo digestibility of the raw and the popped seeds, although the in vitro digestibility was slightly higher for the popped samples. The protein efficiency ratio (PER) for all the amaranth seed samples was higher than that for the wheat sample, while the PER for the raw amaranth seed samples was close to that for the casein reference protein. The rat blood serum levels of total cholesterol, triglycerides and high-density lipoprotein cholesterol for all the amaranth samples were lower than those for the reference protein, while the wheat flour sample showed the lowest values. Copyright © 2004 Society of Chemical Industry [source] Nerve growth factor mediates steroid-resistant inflammation in respiratory syncytial virus infection,,PEDIATRIC PULMONOLOGY, Issue 6 2007Lida Mohtasham MD Abstract Neurotrophic factors and receptors are upregulated in the respiratory tract of humans and rodents infected by the respiratory syncytial virus, leading to airway inflammation and hyperreactivity. The contribution of neurotrophic pathways to the recruitment of immuno-inflammatory cells and their response to anti-inflammatory therapy remains unclear. We sought to determine whether selective nerve growth factor inhibition prevents the immuno-inflammatory response against infection, and explored the effect of inhaled corticosteroids on virus-induced neurotrophic upregulation and the consequent recruitment of immuno-inflammatory cells into the airways. We tried to inhibit the recruitment of lymphocytes and monocytes into the airways of infected weanling rats using immunologic inhibition of nerve growth factor with a specific blocking antibody, or chemical inhibition of receptor tyrosine kinase with K252a. The anti-inflammatory activity of inhaled corticosteroids was studied in infected rats treated with budesonide, fluticasone, or vehicle. Immunological or chemical inhibition of nerve growth factor or its high-affinity receptor tyrosine kinase pathway inhibited the recruitment of inflammatory cells triggered by nociceptive irritation of infected rat airways, thereby reducing local and systemic immuno-inflammatory responses against the virus. Neurotrophic upregulation in infected airways was not affected by inhaled corticosteroids. As a logical consequence, these commonly used drugs were also unable to stop the recruitment of immune and inflammatory effector cells into infected airways. Overexpression of neurotrophic factors and receptors in airways infected by respiratory syncytial virus is critical for the development of airway inflammation and hyperreactivity, which is resistant to the anti-inflammatory effect of inhaled corticosteroids. Pediatr Pulmonol. 2007; 42:496,504. © 2007 Wiley-Liss, Inc. [source] | ||||||||||