Leptin and GABA Interactions on Body Temperature of Rats with Experimental Model of Obesity
Milen H. Hristov
Department of Pharmacology and Toxicology, Faculty of Medicine, Medical University of Sofia, Bulgaria
Elisabetta Di Blasi
Department of Pharmacology and Toxicology, Faculty of Medicine, Medical University of Sofia, Bulgaria
Rumen P. Nikolov
Department of Pharmacology and Toxicology, Faculty of Medicine, Medical University of Sofia, Bulgaria
Krassimira S. Yakimova *
Department of Pharmacology and Toxicology, Faculty of Medicine, Medical University of Sofia, Bulgaria
*Author to whom correspondence should be addressed.
Abstract
Leptin as well as gamma-aminobutyric acid (GABA) are involved in the regulation of feeding behavior and energy balance. The present study determined the effect of leptin on the core body temperature in rats with experimental model of obesity, as well as the changes of body temperature in obese rats after systemic (i.p.) administration of GABAB-agonist baclofen and GABAB-antagonist CGP35348, applied separately or in combinations with leptin. The results suggested significant changes in the effects of substances on rats with experimental model of obesity in comparison with their effects on rats with normal weight. Leptin produced significant long lasting hyperthermia, the hyperthermic effect of GABAB-antagonist CGP35348 was relatively short lasting, while the GABAB-agonist baclofen caused longer lasting hypothermia. The hyperthermic effect of leptin didn’t appear when applied in combination with baclofen. There wasn’t synergism in hyperthermic effect of leptin and GABAB-antagonist applied simultaneously. Our results provide new point of view on the complex interactions between thermoregulation and energy homeostasis.
Keywords: Leptin, GABA, body temperature, obesity, interaction