Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Thyroid hormone regulates food intake. We previously reported that rats with triiodothyronine (T3)-induced thyrotoxicosis display hyperphagia associated with suppressed circulating leptin levels, increased hypothalamic neuropeptide Y (NPY) mRNA and decreased hypothalamic pro-opiomelanocortin (POMC) mRNA. AMP-activated kinase (AMPK) is a serine/threonine protein kinase that is activated when cellular energy is depleted. We hypothesized that T3 causes an increase in hypothalamic AMPK activity, which in turn contributes to the development of T3-induced hyperphagia. Rats that were given s.c. injections of T3 (4.5 nmol/kg) had increased food intake 2 h later without alterations in NPY and POMC mRNA levels, but with increased hypothalamic phosphorylated AMPK (169%) and phosphorylated acetyl-CoA carboxylase (194%). To determine the more chronic effects of T3, rats were given 6 daily s.c. injection of T3 or the vehicle. Food intake was significantly increased. Multiple T3 injections increased hypothalamic phosphorylated AMPK (278%) and phosphorylated acetyl-CoA carboxylase (335%) compared to the controls. Intracerebroventricular administration of compound C, an AMPK inhibitor, blocked the food intake induced by a single or multiple injections of T3. Taken together, these results suggest that enhanced hypothalamic AMPK phosphorylation contributes to T3-induced hyperphagia. Hypothalamic AMPK plays an important role in the regulation of food intake and body weight.
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PMID:Triiodothyronine (T3) stimulates food intake via enhanced hypothalamic AMP-activated kinase activity. 1870 95

Metformin appears to be involved in altering energy expenditure and thermogenesis, and could affect hypothalamic feeding circuits. However, it is not clear whether metformin is able to cross the blood-brain barrier (BBB) to reach the hypothalamus and exert a direct effect on the central nervous system. Here we show the presence of metformin in cerebrospinal fluid (CSF) of diabetic rats administered orally with metformin which was confirmed by detecting the concentration of metformin with liquid chromatography-tandem mass spectrometry. Food intake of diabetic rats treated with metformin was reduced, and glucose homeostasis was gained. Expression of orexigenic peptides neuropeptide Y (NPY) and agouti-related protein (AgRP) decreased in the hypothalamus of metformin-treated diabetic rats, though anorexigenic peptides pro-opiomelanocortin (POMC) did not change significantly. The phosphorylation of signal transducer and activator of transcription 3 (STAT3) was increased but phosphorylated AMP-activated kinase (AMPK) was similar in the hypothalamus of metformin-treated diabetic rats. Our findings suggest that metformin may cross BBB and play a central mechanism on regulation of food intake in the hypothalamus. The anorexic effect of metformin may be mediated by inhibition of NPY and AgRP gene expression through the STAT3 signaling pathway.
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PMID:The effect of metformin on food intake and its potential role in hypothalamic regulation in obese diabetic rats. 2232 91

In diet-induced obesity, metformin (MF) has weight-lowering effect and improves glucose homeostasis and insulin sensitivity. However, there is no information on the efficiency of MF and the mechanisms of its action in melanocortin-type obesity. We studied the effect of the 10-day treatment with MF at the doses of 200, 400 and 600 mg/kg/day on the food intake and the metabolic and hormonal parameters in female C57Bl/6J (genotype Ay/a) agouti-mice with melanocortin-type obesity, and the influence of MF on the hypothalamic signaling in obese animals at the most effective metabolic dose (600 mg/kg/day). MF treatment led to a decrease in food intake, the body and fat weights, the plasma levels of glucose, insulin and leptin, all increased in agouti-mice, to an improvement of the lipid profile and glucose sensitivity, and to a reduced fatty liver degeneration. In the hypothalamus of obese agouti-mice, the leptin and insulin content was reduced and the expression of the genes encoding leptin receptor (LepR), MC3- and MC4-melanocortin receptors and pro-opiomelanocortin (POMC), the precursor of anorexigenic melanocortin peptides, was increased. The activities of AMP-activated kinase (AMPK) and the transcriptional factor STAT3 were increased, while Akt-kinase activity did not change from control C57Bl/6J (a/a) mice. In the hypothalamus of MF-treated agouti-mice (10 days, 600 mg/kg/day), the leptin and insulin content was restored, Akt-kinase activity was increased, and the activities of AMPK and STAT3 were reduced and did not differ from control mice. In the hypothalamus of MF-treated agouti-mice, the Pomc gene expression was six times higher than in control, while the gene expression for orexigenic neuropeptide Y was decreased by 39%. Thus, we first showed that MF treatment leads to an improvement of metabolic parameters and a decrease of hyperleptinemia and hyperinsulinaemia in genetically-induced melanocortin obesity, and the specific changes in the hypothalamic signaling makes a significant contribution to this effect of MF.
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PMID:The evidence of metabolic-improving effect of metformin in Ay/a mice with genetically-induced melanocortin obesity and the contribution of hypothalamic mechanisms to this effect. 3087 Apr 82