Search Results
University Paris sud, bat 447, 91405 Orsay Cedex, France
Faculty of Agriculture, Institute of Biochemistry, Food Science and Nutrition, The Hebrew University, Rehovot 76100, Israel
Search for other papers by Sami Dridi in
Google Scholar
PubMed
University Paris sud, bat 447, 91405 Orsay Cedex, France
Faculty of Agriculture, Institute of Biochemistry, Food Science and Nutrition, The Hebrew University, Rehovot 76100, Israel
Search for other papers by Mohammed Taouis in
Google Scholar
PubMed
University Paris sud, bat 447, 91405 Orsay Cedex, France
Faculty of Agriculture, Institute of Biochemistry, Food Science and Nutrition, The Hebrew University, Rehovot 76100, Israel
Search for other papers by Arieh Gertler in
Google Scholar
PubMed
University Paris sud, bat 447, 91405 Orsay Cedex, France
Faculty of Agriculture, Institute of Biochemistry, Food Science and Nutrition, The Hebrew University, Rehovot 76100, Israel
Search for other papers by Eddy Decuypere in
Google Scholar
PubMed
University Paris sud, bat 447, 91405 Orsay Cedex, France
Faculty of Agriculture, Institute of Biochemistry, Food Science and Nutrition, The Hebrew University, Rehovot 76100, Israel
Search for other papers by Johan Buyse in
Google Scholar
PubMed
Emerging evidence suggests a potential role of stearoyl-CoA desaturase (SCD)-1 in the control of body weight and energy homeostasis. The present study was conducted to investigate the effects of several energy balance-related factors (leptin, cerulenin, food deprivation, genotype, and gender) on SCD gene expression in chickens. In experiment 1, 6-week-old female and male broiler chickens were used. In experiment 2, two groups of 3-week-old broiler chickens were continuously infused with recombinant chicken leptin (8 μg/kg/h) or vehicle for 6 h. In experiment 3, two groups of 2-week-old broiler chickens received i.v. injections of cerulenin (15 mg/kg) or vehicle. In experiment 4, two broiler chicken lines (fat and lean) were submitted to two nutritional states (food deprivation for 16 or 24 h and feeding ad libitum). At the end of each experiment, tissues were collected for analyzing SCD gene expression. Data from experiment 1 showed that SCD is ubiquitously expressed in chicken tissues with highest levels in the proventriculus followed by the ovary, hypothalamus, kidney, liver, and adipose tissue in female, and hypothalamus, leg muscle, pancreas, liver, and adipose tissue in male. Female chickens exhibited significantly higher SCD mRNA levels in kidney, breast muscle, proventriculus, and intestine than male chickens. However, hypothalamic SCD gene expression was higher in male than in female (P < 0.05). Leptin increased SCD gene expression in chicken liver (P < 0.05), whereas cerulenin decreased SCD mRNA levels in muscle. Both leptin and cerulenin significantly reduced food intake (P < 0.05). Food deprivation for either 16 or 24 h decreased the hepatic SCD gene expression in fat line and lean line chickens compared with their fed counterparts (P < 0.05). The hypothalamic SCD mRNA levels were decreased in both lines only after 24 h of food deprivation (P < 0.05). In conclusion, SCD is ubiquitously expressed in chickens and it is regulated by leptin, cerulenin, nutritional state, and gender in a tissue-specific manner.
Search for other papers by K J Oliveira in
Google Scholar
PubMed
Search for other papers by G S M Paula in
Google Scholar
PubMed
Search for other papers by R H Costa-e-Sousa in
Google Scholar
PubMed
Search for other papers by L L Souza in
Google Scholar
PubMed
Search for other papers by D C Moraes in
Google Scholar
PubMed
Search for other papers by F H Curty in
Google Scholar
PubMed
Search for other papers by C C Pazos-Moura in
Google Scholar
PubMed
Peptide YY (PYY)3-36 is a gut-derived hormone, with a proposed role in central mediation of postprandial satiety signals, as well as in long-term energy balance. In addition, recently, the ability of the hormone to regulate gonadotropin secretion, acting at pituitary and at hypothalamus has been reported. Here, we examined PYY3-36 effects on thyrotropin (TSH) secretion, both in vitro and in vivo. PYY3-36-incubated rat pituitary glands showed a dose-dependent decrease in TSH release, with 44 and 62% reduction at 10−8 and 10−6 M (P < 0.05 and P < 0.001 respectively), and no alteration in TSH response to thyrotropin-releasing hormone. In vivo, PYY3-36 i.p. single injection in the doses of 3 or 30 cg/kg body weight, administered to rats fed ad libitum, was not able to change serum TSH after 15 or 30 min. However, in fasted rats, PYY3-36 at both doses elicited a significant rise (approximately twofold increase, P < 0.05) in serum TSH observed 15 min after the hormone injection. PYY3-36 treatment did not modify significantly serum T4, T3, or leptin. Therefore, in the present paper, we have demonstrated that the gut hormone PYY3-36 acts directly on the pituitary gland to inhibit TSH release, and in the fasting situation, in vivo, when serum PYY3-36 is reduced, the activity of thyroid axis is reduced as well. In such a situation, systemically injected PYY3-36 was able to acutely activate the thyrotrope axis, suggesting a new role for PYY3-36 as a regulator of the hypothalamic–pituitary–thyroid axis.
Search for other papers by Nirun Hewawasam in
Google Scholar
PubMed
Search for other papers by Debalina Sakar in
Google Scholar
PubMed
Search for other papers by Olivia Bolton in
Google Scholar
PubMed
Search for other papers by Blerinda Delishaj in
Google Scholar
PubMed
Search for other papers by Maha Almutairi in
Google Scholar
PubMed
Search for other papers by Aileen King in
Google Scholar
PubMed
Search for other papers by Ayse S Dereli in
Google Scholar
PubMed
Search for other papers by Chloe Despontin in
Google Scholar
PubMed
Search for other papers by Patrick Gilon in
Google Scholar
PubMed
Search for other papers by Sue Reeves in
Google Scholar
PubMed
Search for other papers by Michael Patterson in
Google Scholar
PubMed
Search for other papers by Astrid Christine Hauge-Evans in
Google Scholar
PubMed
LEAP2, a liver-derived antagonist for the ghrelin receptor, GHSR1a, counteracts effects of ghrelin on appetite and energy balance. Less is known about its impact on blood glucose-regulating hormones from pancreatic islets. Here we investigate whether acyl-ghrelin (AG) and LEAP2 regulate islet hormone release in a cell type- and sex-specific manner. Hormone content from secretion experiments with isolated islets from male and female mice was measured by radioimmunoassay and mRNA expression by qPCR. LEAP2 enhanced insulin secretion in islets from males (p<0.01) but not females (p<0.2), whilst AG-stimulated somatostatin release was significantly reversed by LEAP2 in males (p<0.001) but not females (p<0.2). Glucagon release was not significantly affected by AG and LEAP2. Ghsr1a, Ghrelin, Leap2, Mrap2, Mboat4 and Sstr3 islet mRNA expression did not differ between sexes. In control male islets maintained without 17-beta oestradiol (E2), AG exerted an insulinostatic effect (p<0.05), with a trend towards reversal by LEAP2 (p=0.06). Both were abolished by 72h E2 pre-treatment (10 nmol/l, p<0.2). AG-stimulated somatostatin release was inhibited by LEAP2 from control (p<0.001) but not E2-treated islets (p<0.2). LEAP2 and AG did not modulate insulin secretion from MIN6 beta cells and Mrap2 was downregulated (P<0.05) and Ghsr1a upregulated (P<0.0001) in islets from Sst-/- mice. Our findings show that AG and LEAP2 regulate insulin and somatostatin release in an opposing and sex-dependent manner, which in males can be modulated by E2. We suggest that regulation of SST release is a key starting point for understanding the role of GHSR1a in islet function and glucose metabolism.
Search for other papers by J P McCann in
Google Scholar
PubMed
Search for other papers by S C Loo in
Google Scholar
PubMed
Search for other papers by D L Aalseth in
Google Scholar
PubMed
Search for other papers by T Abribat in
Google Scholar
PubMed
Abstract
The effect of body condition per se on plasma IGFs and IGF-binding proteins (IGFBPs) and the whole-body metabolic responses to recombinant DNA-derived bovine GH (rbGH) in both the fed and the fasted state were determined in lean and dietary obese sheep (n=6/group). Sheep at zero-energy balance and equilibrium body weight were injected s.c. for 12 days with 100 μg/kg rbGH immediately before their morning feeding. Before GH treatment, fasting plasma concentrations of insulin (17·0 ± 1·9 vs 7·5 ± 0·7 μU/ml), IGF-I (345 ± 25 vs 248 ± 10 ng/ml), glucose (52·6 ± 1·1 vs 48·3 ± 0·7 mg/dl), and free fatty acid (FFA) (355 ± 45 vs 229 ± 24 nmol/ml) were greater (P<0·05) and those of GH (1·1 ± 0·2 vs 2·6 ± 0·3 ng/ml) were lower (P<0·05) in obese than in lean sheep. Fasting concentrations of IGF-II and glucagon were not affected (P>0·05) by obesity. GH concentrations were increased equivalently by 6–9 ng/ml in lean and obese sheep during GH treatment. GH caused an immediate and a marked fivefold increase in the fasting insulin level in obese sheep but only minimally affected insulin concentration in lean sheep. The increment in fasting glucose during GH treatment was greater (P<0·05) in obese (8–12 mg/dl) than in lean (2–5 mg/dl) sheep. Frequent measurements in the first 8 h after feeding and injection of excipient (day 0) or the first (day 1), sixth (day 6) and twelfth (day 12) daily injection of GH showed that prandial metabolism in both groups of sheep was affected minimally by GH. However, GH treatment on day 1 (not days 6 or 12) acutely attenuated the feeding-induced suppression of plasma FFA in both groups of sheep and this effect was significantly greater in obese than in lean sheep.
Although obese sheep were hyposomatotropic, the basal and GH-induced increases in plasma IGF-I concentrations were greater (P<0·05) in obese than in lean sheep. Plasma IGF-II was unaffected by obesity and was not increased by GH stimulation. Western ligand blotting showed that IGFBP-3 accounted for approximately 50–60% of the plasma IGF-I binding capacity in sheep respectively both before and during GH treatment. Basal plasma levels of IGFBP-2 were lower (P<0·05) and those of IGFBP-3 greater (P<0·05) in obese compared with lean sheep. GH increased the level of IGFBP-3 equally in lean and obese sheep, but suppressed the expression of IGFBP-2 more (P<0·05) in lean than in obese sheep. We concluded that the diabetogenic-like actions of GH in sheep were exaggerated markedly by obesity, and were expressed more during the fasted than the fed states. The effects of GH stimulation on the endocrine pancreas may be selective for β-cells and preferentially enhanced by obesity. GH regulation of IGF-I and the IGFBPs differs in lean and obese sheep.
Journal of Endocrinology (1997) 154, 329–346
Search for other papers by DJ Flint in
Google Scholar
PubMed
Search for other papers by RG Vernon in
Google Scholar
PubMed
Exogenous GH is used extensively in the USA to stimulate milk production in dairy cattle but its effectiveness is reduced in undernourished animals. It has been proposed that GH increases milk yield by stimulating IGF-I secretion and that this IGF-I-response is nutritionally sensitive and thus acts as a 'sensor' of energy balance. To investigate this possibility, we placed lactating rats on three planes of nutrition, ad libitum, 50% or 25% of ad libitum for 48 h. Subgroups of these animals were treated for 48 h with bromocriptine, to suppress prolactin secretion, and anti-rat GH, to neutralize GH action. From 24 to 48 h some of the treated animals were assessed for their milk yield response to prolactin or GH. Food restriction reduced milk yield in control rats by approximately 50% and was accompanied by a catabolic state, as judged by lipid mobilization from adipose tissue and by low concentrations of serum insulin, IGF-I, triiodothyronine and thyroxine, and increased serum nonesterified fatty acid concentrations. In animals fed ad libitum, anti-rat GH plus bromocriptine treatment produced an 80% decrease in milk yield and a dramatic fall in the activity of acetyl-CoA carboxylase in mammary tissue. GH was able to stimulate milk yield when given from 24 to 48 h; however, its effectiveness decreased progressively as food intake was reduced. The milk yield response to GH was accompanied by an increase in serum IGF-I concentrations and this response also decreased progressively with reduction of food intake, consistent with the hypothesis that IGF-I determines the milk yield response to GH and thus regulates GH action on the mammary gland in a nutritionally dependent fashion. However, the milk yield response to prolactin and the milk yield of control rats decreased in line with food intake without any changes in serum IGF-I concentrations. This clearly indicates that factors other than IGF-I are responsible for restricting milk yield. In order to assess other possible candidates for this role, we monitored serum glucose, non-esterified fatty acids, insulin triiodothyronine and thyroxine concentrations, but found no evidence for any simple relationship between these parameters and the milk yield response to prolactin and GH. Surprisingly we found that the ability of GH or prolactin to prevent epithelial cell loss in in the mammary gland was completely insensitive to nutrient intake, despite the fact that IGF-I is considered to be an important survival factor for mammary epithelial cells. Finally, we also demonstrated that, at least during short-term food restriction, the lactating rat is capable of mobilizing significant amounts of lipid from adipose tissue, such that it could provide the total output of triglyceride in milk, which is much greater than has previously been proposed.
Veterinary Medicine and Surgery,
Animal Sciences, University of Missouri-Columbia, Columbia, Missouri 56211, USA
Search for other papers by Preston R Buff in
Google Scholar
PubMed
Veterinary Medicine and Surgery,
Animal Sciences, University of Missouri-Columbia, Columbia, Missouri 56211, USA
Search for other papers by Nat T Messer IV in
Google Scholar
PubMed
Veterinary Medicine and Surgery,
Animal Sciences, University of Missouri-Columbia, Columbia, Missouri 56211, USA
Search for other papers by Andria M Cogswell in
Google Scholar
PubMed
Veterinary Medicine and Surgery,
Animal Sciences, University of Missouri-Columbia, Columbia, Missouri 56211, USA
Search for other papers by David A Wilson in
Google Scholar
PubMed
Veterinary Medicine and Surgery,
Animal Sciences, University of Missouri-Columbia, Columbia, Missouri 56211, USA
Search for other papers by Philip J Johnson in
Google Scholar
PubMed
Veterinary Medicine and Surgery,
Animal Sciences, University of Missouri-Columbia, Columbia, Missouri 56211, USA
Search for other papers by Duane H Keisler in
Google Scholar
PubMed
Veterinary Medicine and Surgery,
Animal Sciences, University of Missouri-Columbia, Columbia, Missouri 56211, USA
Search for other papers by Venkataseshu K Ganjam in
Google Scholar
PubMed
. 2000 ). Leptin acts on hypothalamic receptors to modulate energy balance as a signal to control food intake and energy expenditure ( Campfield et al. 1995 , Ahima et al. 1996 ). In regulating energy homeostasis, leptin is the most effective when
Search for other papers by F Wahab in
Google Scholar
PubMed
Search for other papers by M Shahab in
Google Scholar
PubMed
Search for other papers by R Behr in
Google Scholar
PubMed
) from the hypothalamus, thus causing reproductive quiescence ( Bergendahl et al . 1991 , Cameron et al . 1991 , Wahab et al . 2013 a , b ). Initiation of reproductive function is delayed by conditions of negative energy balance while, in adults
Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima-shi, Hiroshima 739-8528, Japan
National Cardiovascular Center Research Institute, Osaka 565-8565, Japan
Search for other papers by Hideyuki Takahashi in
Google Scholar
PubMed
Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima-shi, Hiroshima 739-8528, Japan
National Cardiovascular Center Research Institute, Osaka 565-8565, Japan
Search for other papers by Yohei Kurose in
Google Scholar
PubMed
Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima-shi, Hiroshima 739-8528, Japan
National Cardiovascular Center Research Institute, Osaka 565-8565, Japan
Search for other papers by Muneyuki Sakaida in
Google Scholar
PubMed
Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima-shi, Hiroshima 739-8528, Japan
National Cardiovascular Center Research Institute, Osaka 565-8565, Japan
Search for other papers by Yoshihiro Suzuki in
Google Scholar
PubMed
Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima-shi, Hiroshima 739-8528, Japan
National Cardiovascular Center Research Institute, Osaka 565-8565, Japan
Search for other papers by Shigeki Kobayashi in
Google Scholar
PubMed
Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima-shi, Hiroshima 739-8528, Japan
National Cardiovascular Center Research Institute, Osaka 565-8565, Japan
Search for other papers by Toshihisa Sugino in
Google Scholar
PubMed
Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima-shi, Hiroshima 739-8528, Japan
National Cardiovascular Center Research Institute, Osaka 565-8565, Japan
Search for other papers by Masayasu Kojima in
Google Scholar
PubMed
Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima-shi, Hiroshima 739-8528, Japan
National Cardiovascular Center Research Institute, Osaka 565-8565, Japan
Search for other papers by Kenji Kangawa in
Google Scholar
PubMed
Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima-shi, Hiroshima 739-8528, Japan
National Cardiovascular Center Research Institute, Osaka 565-8565, Japan
Search for other papers by Yoshihisa Hasegawa in
Google Scholar
PubMed
Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima-shi, Hiroshima 739-8528, Japan
National Cardiovascular Center Research Institute, Osaka 565-8565, Japan
Search for other papers by Yoshiaki Terashima in
Google Scholar
PubMed
negative energy balance but inhibited under positive energy balance. Overall, it appears that ghrelin may play an important role in glucose metabolism, through modulation of insulin secretion, but this could be dependent on whether the organisms are
Search for other papers by R P Rhoads in
Google Scholar
PubMed
Search for other papers by J W Kim in
Google Scholar
PubMed
Search for other papers by M E Van Amburgh in
Google Scholar
PubMed
Search for other papers by R A Ehrhardt in
Google Scholar
PubMed
Search for other papers by S J Frank in
Google Scholar
PubMed
Search for other papers by Y R Boisclair in
Google Scholar
PubMed
positive net energy balance. Under these conditions, GH attenuates the lipogenic response to insulin and simultaneously amplifies the lipolytic response to β-adrenergic signals ( Bauman & Vernon 1993 ). It is currently thought that these GH actions are
Search for other papers by Richard A Ehrhardt in
Google Scholar
PubMed
Search for other papers by Andreas Foskolos in
Google Scholar
PubMed
Search for other papers by Sarah L Giesy in
Google Scholar
PubMed
Search for other papers by Stephanie R Wesolowski in
Google Scholar
PubMed
Search for other papers by Christopher S Krumm in
Google Scholar
PubMed
Search for other papers by W Ronald Butler in
Google Scholar
PubMed
Search for other papers by Susan M Quirk in
Google Scholar
PubMed
Search for other papers by Matthew R Waldron in
Google Scholar
PubMed
Search for other papers by Yves R Boisclair in
Google Scholar
PubMed
surrounding parturition ( Block et al . 2001 , Reist et al . 2003 , Janovick et al . 2011 ). This rapid reduction in plasma leptin was caused by the onset of negative energy balance rather than depletion of adipose tissue or loss of the placenta ( Block
