Effects of chronic intraperitoneal administration of the GABA-B receptor agonist 3-aminopropyl (methyl) phosphinic acid on food intake and body weight in rats

Abstract

Previous research indicates that chronic intraperitoneal (ip) administration of the GABAB receptor agonist baclofen reduces body weight gain in rats without altering daily food intake. The present study was undertaken to extend these observations by investigating the effects of chronic ip administration of the potent GABAB receptor agonist 3-aminopropyl (methyl) phosphinic acid (SKF-97541) on daily changes on body weight and food intake in free feeding rats. The animals were injected ip once daily with SKF-97541 (0.1 mg / kg for 5 days, followed by 0.2 mg / kg for 8 days; Experiment 1) or SKF-97542 (0.4 mg / kg) for 17 days (Experiment 2). Control animals received physiological saline in both experiments. While daily food intake did not differ significantly between groups, the SKF-97541 group exhibited significant reductions in body weight gain compared to controls. These results extend previous findings and show that systemic administration of SKF-97541 suppresses weight gain independently of caloric intake, and lend further support to the hypothesis that GABAB receptor agonists decrease body weight primarily by increasing metabolic rate.