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Plasma Leptin (plasma + leptin)
Terms modified by Plasma Leptin Selected Abstracts47 Effects of retrograde gastric electrical stimulation on gastric motility and plasma hormones in dogsNEUROGASTROENTEROLOGY & MOTILITY, Issue 6 2006G SONG Aims:, The aim of this study was to investigate the effect of different parameters of RGES with trains of long pulses in turning gastric slow waves into tachygastria, and evaluate the effects of RGES with the efficient trains of pulses on gastric slow waves, gastric emptying of solids and plasma concentrations of satiety-related peptides and glucose. Methods:, Seven female dogs implanted with four pairs of gastric electrodes were studied in two experiments. The first experiment included a series of sessions with different pacing parameters in the fasting state, each lasting 10 min. The second experiment included two randomized sessions (control and RGES). Gastric emptying of solid was measured by scintigraphy for a period of 4 h. Blood samples were collected at 45 and 15 min before, 30, 60 and 120 min after the meal. Plasma leptin, insulin and glucagon were measured using radioimmunoassay method. Plasma glucose was assessed with a commercially available glucometer. RGES was applied via the distal pair of electrodes (2 cm above the pylorus) with trains of pulses. RGES was initiated 30 min before the first blood sample and maintained for a period of 2.5 h. Gastric slow waves and symptomatic response were also recorded in each session. Results:, (1) RGES with pulse trains (12 trains/min) was able to turn regular gastric slow waves into tachygastria. (2) RGES with the efficient parameters (frequency: 40 Hz; pulse width: 2 ms; amplitude: 5 mA; train on-time, 2 s; off-time, 3 s) was capable of delaying gastric emptying of solids (P < 0.05). (3) Compared with the control session without RGES, the total AUC's of plasma insulin with RGES was significantly decreased in the fasting and postprandial periods (p < 0.05). However, the total area under curves (AUC's) of plasma leptin, glucagon, and glucose were not significantly affected by RGES (p > 0.05). (4) This method of GES induced no noticeable symptoms. Conclusion:, RGES with at a tachygastrial frequency decreases gastric emptying of solids and plasma insulin, but has no effects on plasma leptin, glucagons, and glucose. [source] Pregnancy and lactation have anti-obesity and anti-diabetic effects in Ay/a miceACTA PHYSIOLOGICA, Issue 2 2010E. N. Makarova Abstract Aim:, Dominant ,yellow' mutation at the mouse agouti locus (Ay) results in obesity. Pregnancy and lactation are characterized by large energy demand. The aim of this study was to investigate whether obesity would develop in pregnant and suckling Ay mice. Methods:, Body weight and food intake in pregnancy, lactation, and after weaning, plasma leptin, insulin, corticosterone and blood glucose concentrations on days 7, 13 and 18 of pregnancy, days 1, 10, 21 and 80 postpartum, glucose and insulin tolerance on pregnancy days 7 and 18 were measured in C57Bl/6J mice of a/a (normal metabolism) and Ay/a genotypes. The same parameters were also measured in age-matched virgin females. Results:, Virgin Ay/a females exhibited hyperphagia, enhanced body weight, glucose intolerance and normal blood parameters at the mating age. With age, they developed obesity, hyperleptinaemia, hyperinsulinaemia and hyperglycaemia. Obesity did not develop in mated Ay/a mice; during suckling, they had equal food intake and body weight as a/a mice. During pregnancy, glucose tolerance was enhanced in Ay/a mice and became equal in both genotypes. In both genotypes, concentrations of hormones increased, and glucose decreased from pregnancy day 7 to day 18 and returned to normal values after parturition. Ay/a mice did not differ from a/a in corticosterone, insulin and glucose levels during pregnancy and lactation, in leptin levels during suckling; however, Ay/a mice had two times higher leptin levels than a/a during pregnancy. After weaning, Ay/a mice began to eat and weigh more than a/a exhibiting normal metabolic parameters for 50 days. Conclusion:, Pregnancy and lactation retard obesity and diabetes development in Ay mice. [source] Genetic variation and decreased risk for obesity in the Atherosclerosis Risk in Communities StudyDIABETES OBESITY & METABOLISM, Issue 4 2007M. L. Hart Sailors Aim:, To investigate the effects of variation in the leptin [LEP (19A>G)] and melanocortin-4 receptor [MC4R (V103I)] genes on obesity-related traits in 13,405 African-American (AA) and white participants from the Atherosclerosis Risk in Communities (ARIC) Study. Methods:, We tested the association between the single-locus and multilocus genotypes and obesity-related measures [body mass index (BMI), body weight (BW), waist,hip ratio, waist circumference and leptin levels], adjusted for age, physical activity level, smoking status, diabetic status, prevalence of coronary heart disease, hypertension, stroke or transient ischaemic attack. Results:, AA and white female carriers of the MC4R I103 allele exhibited significantly lower BW than non-carriers of this allele (p < 0.05 and p < 0.01 respectively). AA female carriers of both the LEP A19 allele and the MC4R I103 allele were 63% [odds ratio (OR) = 0.37, 95% confidence interval (CI) (0.18,0.78)] less likely to be obese, and white female carriers of the same two alleles were 46% [OR = 0.54, 95% CI (0.32,0.91)] less likely to be obese, than non-carriers of the variant alleles. Female carriers of both the LEP A19 and MC4R I103 alleles had significantly lower BW (p < 0.05), BMI (p < 0.05) and plasma leptin (p < 0.01) than the non-carriers of both the alleles. Carriers of the two variant alleles had lower BMI over the 9-year course of the ARIC study and significantly lower weight gain from age 25 years. No significant joint effect of these two variants was observed in males. Conclusion:, These results suggest that variation within the LEP and MC4R genes is associated with reduced risk for obesity in females. [source] ORIGINAL ARTICLE: The approach to the mechanism of calcitonin gene-related peptide-inducing inhibition of food intakeJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 5 2010J.-Y. Sun Summary The aim of this study was to investigate the anorectic mechanism of calcitonin gene-related peptide (CGRP) in rats. Intraperitoneal injection of CGRP (50 ,g/kg) resulted in decline (p < 0.05) in the food intake of rats at 0.5, 1, 2 and 4 h in comparison with saline control. Compared with saline-treated group, the levels of hypothalamic 3,,5,-cyclic adenosine monophosphate (cAMP) and plasma glucagon were increased (p < 0.05) in CGRP-treated group, but insulin level was decreased (p < 0.05). No significant changes (p > 0.05) in the plasma leptin were observed between two treatment groups. Calcitonin gene-related peptide injection down regulated (p < 0.05) both neuropeptide Y (NPY) and melanin-concentrating hormone (MCH) genes at mRNA levels, but up regulated (p < 0.05) the expression of cholecystokinin (CCK) gene. The correlations analysis showed that food intake was negatively correlated (p < 0.05) with CCK mRNA, cAMP and glucagon levels. Moreover, there existed negative correlations (p < 0.05) between MCH mRNA and glucagon levels, and positive correlations (p < 0.05) between insulin and leptin levels. The results showed that cAMP acting as the second messenger may play a vital role in the anorectic effects of CGRP. Calcitonin gene-related peptide could stimulate anorexigenic neuropeptides (i.e. CCK) and/or inhibit orexigenic neuropeptides (i.e. NPY and MCH) expression, and ultimately suppressed food intake that was functionally coupled to cAMP/PKA pathway activation. [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] Cachexia in MAC16 adenocarcinoma: suppression of hunger despite normal regulation of leptin, insulin and hypothalamic neuropeptide YJOURNAL OF NEUROCHEMISTRY, Issue 5 2001Chen Bing Weight loss normally stimulates hunger, through mechanisms that include falls in circulating leptin and insulin, leading to stimulation of hypothalamic neuropeptide Y (NPY). Here, we investigated the leptin, insulin and NPY to clarify why hunger is suppressed in mice with severe cachexia due to the MAC16 adenocarcinoma. MAC16-bearing mice progressively lost weight (19% below controls) and fat (,,61%) over 16 days after tumour transplantation, while total food intake fell by 10%. Pair-fed mice showed less wasting, with final weight being 9% and fat mass 25% below controls. Plasma leptin fell by 85% in MAC16 and 51% in pair-fed mice, in proportion to loss of fat. Plasma insulin was also reduced by 49% in MAC16 and 53% in pair-fed groups. Hypothalamic leptin receptor (OB-Rb) mRNA was significantly increased in both MAC16 (+ 223%) and pair-fed (+192%) mice. Hypothalamic NPY mRNA was also significantly raised in MAC16 (+152%) and pair-fed (+ 99%) groups, showing negative correlations with plasma leptin and insulin, and a positive association with OB-Rb mRNA. In MAC16-induced cachexia, leptin production and hypothalamic OB-Rb and NPY expression are regulated appropriately in response to fat depletion. Therefore, suppression of hunger is probably due to tumour products that inhibit NPY transport or release, or that interfere with neuronal targets downstream of NPY. [source] Adenovirus-Mediated Leptin Expression Normalises Hypertension Associated with Diet-Induced ObesityJOURNAL OF NEUROENDOCRINOLOGY, Issue 3 2010W. Zhang In our previous study, moderate increases in plasma leptin levels achieved via administration of recombinant adenovirus containing the rat leptin cDNA were shown to correct the abnormal metabolic profile in rats with diet-induced obesity, suggesting that these animals had developed resistance to the metabolic effects of leptin, which could be reversed by leptin gene over-expression. However, the effect of this therapeutic strategy on blood pressure was not investigated. The present study aimed to determine whether a moderate increase of endogenous plasma leptin levels affected arterial blood pressure in rats with diet-induced obesity and hypertension. The major finding from the present study was that the natural rise in plasma leptin with weight-gain is insufficient to counterbalance high blood pressure associated with obesity, additional increases of circulating leptin levels with adenoviral leptin gene therapy led to normalisation of blood pressure in high-fat diet-induced obese and hypertensive rats. Mechanistically, the reduction of blood pressure by leptin in obese rats was likely independent of ,-adrenergic and acetylcholinergic receptor mediation. This is the first study to demonstrate that further increases in circulating leptin levels by leptin gene transfer during obesity could reduce blood pressure. [source] 47 Effects of retrograde gastric electrical stimulation on gastric motility and plasma hormones in dogsNEUROGASTROENTEROLOGY & MOTILITY, Issue 6 2006G SONG Aims:, The aim of this study was to investigate the effect of different parameters of RGES with trains of long pulses in turning gastric slow waves into tachygastria, and evaluate the effects of RGES with the efficient trains of pulses on gastric slow waves, gastric emptying of solids and plasma concentrations of satiety-related peptides and glucose. Methods:, Seven female dogs implanted with four pairs of gastric electrodes were studied in two experiments. The first experiment included a series of sessions with different pacing parameters in the fasting state, each lasting 10 min. The second experiment included two randomized sessions (control and RGES). Gastric emptying of solid was measured by scintigraphy for a period of 4 h. Blood samples were collected at 45 and 15 min before, 30, 60 and 120 min after the meal. Plasma leptin, insulin and glucagon were measured using radioimmunoassay method. Plasma glucose was assessed with a commercially available glucometer. RGES was applied via the distal pair of electrodes (2 cm above the pylorus) with trains of pulses. RGES was initiated 30 min before the first blood sample and maintained for a period of 2.5 h. Gastric slow waves and symptomatic response were also recorded in each session. Results:, (1) RGES with pulse trains (12 trains/min) was able to turn regular gastric slow waves into tachygastria. (2) RGES with the efficient parameters (frequency: 40 Hz; pulse width: 2 ms; amplitude: 5 mA; train on-time, 2 s; off-time, 3 s) was capable of delaying gastric emptying of solids (P < 0.05). (3) Compared with the control session without RGES, the total AUC's of plasma insulin with RGES was significantly decreased in the fasting and postprandial periods (p < 0.05). However, the total area under curves (AUC's) of plasma leptin, glucagon, and glucose were not significantly affected by RGES (p > 0.05). (4) This method of GES induced no noticeable symptoms. Conclusion:, RGES with at a tachygastrial frequency decreases gastric emptying of solids and plasma insulin, but has no effects on plasma leptin, glucagons, and glucose. [source] Role of leptin in the regulation of growth and carbohydrate metabolism in the ovine fetus during late gestationTHE JOURNAL OF PHYSIOLOGY, Issue 9 2008Alison J. Forhead Leptin is an important regulator of appetite and energy expenditure in adulthood, although its role as a nutritional signal in the control of growth and metabolism before birth is poorly understood. This study investigated the effects of leptin on growth, carbohydrate metabolism and insulin signalling in fetal sheep. Crown,rump length-measuring devices and vascular catheters were implanted in 12 sheep fetuses at 105,110 days of gestation (term 145 ± 2 days). The fetuses were infused i.v. either with saline (0.9% NaCl; n= 6) or recombinant ovine leptin (0.5,1.0 mg kg,1 day,1; n= 6) for 5 days from 125 to 130 days when they were humanely killed and tissues collected. Leptin receptor mRNA and protein were expressed in fetal liver, skeletal muscle and perirenal adipose tissue. Throughout infusion, plasma leptin in the leptin-infused fetuses was 3- to 5-fold higher than in the saline-infused fetuses, although plasma concentrations of insulin, glucose, lactate, cortisol, catecholamines and thyroid hormones did not differ between the groups. Leptin infusion did not affect linear skeletal growth or body, placental and organ weights in utero. Hepatic glycogen content and activities of the gluconeogenic enzymes glucose-6-phosphatase and phosphoenolpyruvate carboxykinase in the leptin-infused fetuses were lower than in the saline-infused fetuses by 44, 48 and 36%, respectively; however, there were no differences in hepatic glycogen synthase activity or insulin signalling protein levels. Therefore, before birth, leptin may inhibit endogenous glucose production by the fetal liver when adipose energy stores and transplacental nutrient delivery are sufficient for the metabolic needs of the fetus. These actions of leptin in utero may contribute to the development of neonatal hypoglycaemia in macrosomic babies of diabetic mothers. [source] Effects of castration on insulin levels and glucose tolerance in the mouse differ from those in manTHE PROSTATE, Issue 15 2010Takamitsu Inoue Abstract BACKGROUND Plasma insulin concentration is increased in prostate cancer patients during androgen deprivation therapy (ADT) and hyperinsulinemia has been associated with aggressive prostate cancer behavior. To investigate the possible role of castration-induced hyperinsulinemia as a mechanism that may attenuate the beneficial effects of ADT in patients with prostate cancer, a murine model would be useful. We therefore investigated long-term metabolic effects of castration in several mouse models. METHODS We studied the long-term influence of castration on energy intake, body weight, glucose tolerance, plasma-insulin, plasma insulin-like growth factor-1 (IGF-1), plasma adiponectin, and plasma leptin in C57BL/6, Swiss nu/nu, and CB17 scid mice receiving various diets. In each case, mice were randomized to have either bilateral orchiectomy or a sham operation. RESULTS Energy intake, body weight, blood glucose levels in glucose tolerance test, plasma insulin, plasma IGF-1, and plasma leptin level in all had a trend to be decreased in castrated as compared to sham operated mice. Plasma adiponectin level was increased in the castrated mice. CONCLUSIONS The effects of castration on glucose, insulin, and related markers in several mouse models studied does not coincide with clinical observations; further studies in this area will require clinical research and/or the use of alternate models such as the dog. Prostate 70: 1628,1635, 2010. © 2010 Wiley-Liss, Inc. [source] Effect of fat supplementation during transition period on plasma leptin and non-esterified fatty acid concentrations in Holstein cowsANIMAL SCIENCE JOURNAL, Issue 3 2010Ahmad AFZALZADEH ABSTRACT The objective of this experiment was to investigate the effect of fat supplementation during the transition period on pre and postpartum body weight (BW), body condition score (BCS), non-esterified fatty acids (NEFA), glucose and leptin concentrations in Holstein cows. Holstein cows (n = 15) received a low fat diet (LF; 1.61 Mcal net energy for lactation (NEL)/kg of dry matter [DM]), moderate fat diet (MF; 1.68 Mcal NEL/kg DM) or a high fat diet (HF; 1.74 Mcal NEL/kg DM) for 4 weeks prior to calving. All cows were fed similar lactation diets ad libitum (1.74 Mcal NEL/kg DM) for 30 days after calving. Increasing diet energy density during transition period had no effect on prepartum DMI, BCS, BW, glucose and NEFA concentrations (P > 0.05); but leptin concentrations and energy balance (EB) were affected by treatments (P < 0.05). Animals fed HF had less plasma leptin prepartum. After parturition, BW, milk production, milk fat, protein, urea nitrogen and plasma glucose concentrations were affected by prepartum diets (P < 0.05). Fat supplementation prepartum did not affect postpartum NEFA. In conclusion, prepartum fat supplementation decreased leptin concentration prepartum. [source] Leptin and ghrelin concentrations and weight loss in Parkinson's diseaseACTA NEUROLOGICA SCANDINAVICA, Issue 4 2010U. Fiszer Fiszer U, Micha,owska M, Baranowska B, Woli,ska-Witort E, Jeske W, Jethon M, Pia,cik-Gromada M, Marcinowska-Suchowierska E. Leptin and ghrelin concentrations and weight loss in Parkinson's disease. Acta Neurol Scand: 2010: 121: 230,236. © 2009 The Authors Journal compilation © 2009 Blackwell Munksgaard. Objectives,,, To investigate the role of leptin, ghrelin, GH and IGF-1 in energy balance disturbances in Parkinson's disease (PD). Materials and methods,,, Thirty-nine patients were included: 11 PD patients with unintentional weight loss, 16 PD patients without weight loss and 12 controls. UPDRS, MMSE, MADRS, appetite scale, BMI, adipose tissue content, plasma leptin and active ghrelin concentrations and serum GH, IGF-1, TSH, T3 and T4, concentrations were evaluated. Results,,, A lower plasma leptin concentration and a higher serum IGF-1 concentration were found in PD patients with weight loss. BMI and the content of adipose tissue were positively correlated with leptin concentration in all PD patients. Paradoxically, the lower BMI was, the lower plasma active ghrelin concentration was in PD patients with the weight loss. Conclusion,,, These findings confirm that changes of plasma leptin concentration occur in PD patients with loss of weight. [source] Effect of individualized weight-loss programmes on adiponectin, leptin and resistin levels in obese adolescent boysACTA PAEDIATRICA, Issue 9 2009M Elloumi Abstract Aim:, We investigate the effects of a 2-month weight-loss programme on plasma levels of adiponectin, leptin and resistin in obese adolescent boys. Methods:, Twenty-one obese adolescent boys (BMI = 30.8 ± 3.2 kg/m2) completed the weight-loss programme including: 1/ either energy restriction (R), 2/ or individualized exercise training at the point of maximum lipid oxidation (Lipoxmax) (E), 3/ or energy restriction and training (RE). Body composition, lipid oxidation and plasma levels of adiponectin, leptin and resistin were measured before and after intervention. Results:, Following the weight-loss programme, adolescents of the RE group showed an improvement of their body composition (p < 0.01), an increase in plasma adiponectin (+73.7%, p < 0.01) and a decrease in plasma leptin (,38.8%, p < 0.01) leading to an increase in adiponectine/leptin ratio (ALR, +144.4%, p < 0.01) higher than the R or E groups. E and RE groups only showed a similar significant increase in plasma resistin (p < 0.05) and a significant improvement of lipid oxidation rate at Lipoxmax (p < 0.01 and p < 0.001). In addition, in RE group, ALR is correlated with waist/hip and waist/height ratios, resistin level, homoeostasis mode assessment (HOMA-IR) index and Lipoxmax. Conclusion:, In obese adolescents boys, moderate exercise training completed at Lipoxmax and combined with energy restriction improves their ability to oxidize lipids, which is associated with a normalization of their adiponectin, leptin and resistin levels resulting in an improved insulin sensitivity, as attested by a higher ALR and a lower HOMA-IR. [source] | |||||||||||||