Interaction of Glycine and Isoproterenol on Peripheral Regulation of Food Intake in Rats

Abstract

Introduction The appetite regulatory role of glycine as a neurotransmitter and neuromodulator has been demonstrated. The present study was aimed to investigate the interaction between glycine and beta-adrenergic receptors in regulating food intake in rats. Materials and Methods Forty male Wistar rats that weighed 250-300 g were used in this study. The present study was carried out in four periods. The interval between each period was three days. Rats received i.p. injections of various combinations of isoproterenol, glycine, and postsynaptic glycine receptor antagonist (strychnine hydrochloride). Food consumption was recorded 60,120 and 180 min after injection. Results Intraperitoneal injection of glycine 100,200 and 400 mg/kg BW significantly increased food consumption in all injection times (P<0.05). Injection of strychnine hydrochloride (8mg/kg) significantly decreased food intake 120 and 180 min postinjection (P<0.05). Pretreatment with isoproterenol did not affect glycine-induced hyperphagia in rats. Furthermore, pretreatment with isoproterenol had no significant effect on strychnine induced anorexia. Conclusion The appetizing effect glycine in the rats is possibly independent from the peripheral beta-adrenergic receptors.

Keywords

• Adrenergic receptors
• glycine
• food intake
• Rat