sb-242084 and Weight-Loss

Glucagon-like peptide 1 (GLP-1) and serotonin play critical roles in energy balance regulation. Both systems are exploited clinically as antiobesity strategies. Surprisingly, whether they interact in order to regulate energy balance is poorly understood. Here we investigated mechanisms by which GLP-1 and serotonin interact at the level of the central nervous system. Serotonin depletion impaired the ability of exendin-4, a clinically used GLP-1 analog, to reduce body weight in rats, suggesting that serotonin is a critical mediator of the energy balance impact of GLP-1 receptor (GLP-1R) activation. Serotonin turnover and expression of 5-hydroxytryptamine (5-HT) 2A (5-HT

Topics: Aminopyridines; Animals; Anorexia; Appetite; Body Weight; Dorsal Raphe Nucleus; Exenatide; Feeding Behavior; Fenclonine; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Hypoglycemic Agents; Indoles; Liraglutide; Male; Peptides; Pyrrolidines; Rats; Rats, Sprague-Dawley; Receptor, Serotonin, 5-HT2A; Receptor, Serotonin, 5-HT2C; Serotonin; Serotonin Antagonists; Venoms; Weight Loss

Food intake and energy expenditure are the two main determinants of body weight. Given that 5-HT(2C) receptor agonists are reported to have effects on both energy expenditure and food intake, this strongly suggests that 5-HT(2C) receptor agonists have excellent potential for development as antiobesitiy drugs. One important issue in antiobesity drug development is whether the effects of the compound are maintained during chronic drug treatment.. The purpose of the present study was to investigate the effect of repeated oral administration of three 5-HT(2C) receptor agonists, m-chlorophenylpiperazine (mCPP), d(S)-2-(6-chloro-5-fluoroindol-1-yl)-1-methylethylamine (RO60-0175) and (S)-2-(7-ethyl-1H-furo[2,3-g]indazol-1-yl)-1-methylethylamine (YM348), on food intake and energy expenditure in rats.. In the food intake study, mCPP, RO60-0175 and YM348 decreased food intake in a dose-dependent manner on day 1 of administration. On day 14 of repeated administration, the hypophagic effect of YM348 was lost and that of mCPP was reduced. In contrast, the hypophagic effect of RO60-0175 was maintained even after repeated administration. The hypophagic effects of all agonists were significantly inhibited by a 5-HT(2C) receptor antagonist, SB242084. In contrast to the hypophagic effects, no drug tolerance developed with respect to the hyperthermic effects of mCPP, RO60-0175, and YM348. The hyperthermic effects of these drugs were also inhibited by SB242084.. Together, the difference between compounds in their hypophagic effects and the similarity in their hyperthermic effects suggest a diversity in agonists in 5-HT(2C) receptor-mediated weight control in rats.

Topics: Administration, Oral; Aminopyridines; Animals; Appetite Depressants; Dose-Response Relationship, Drug; Drug Interactions; Energy Metabolism; Ethylamines; Feeding Behavior; Indazoles; Indoles; Male; Piperazines; Rats; Rats, Wistar; Serotonin 5-HT2 Receptor Agonists; Weight Loss