Insulin and leptin plasma levels after the microinjection of interleukin-1β into the nucleus accumbens of the rat

The nucleus accumbens (NAcc), an important basal forebrain structure, has a central integratory function in the control of feeding and metabolism. The primary cytokine interleukin-1β (IL-1β) exerts its neuromodulatory effects on the endocrine functions both centrally and peripherally. The present study was designed to elucidate the possible consequences of direct administration of IL-1β into the NAcc on the endocrine regulation of metabolism. Plasma concentrations of insulin and leptin, two key hormones in the homeostatic control were determined 15 minutes after a single bilateral microinjection of IL-1β into the NAcc of adult male Wistar rats, and the effects were compared with those found in vehicle treated control animals. Insulin plasma levels of the cytokine treated animals were significantly higher than those parameters of the control rats. No differences were found in leptin plasma concentrations between the two groups. Our findings show that IL-1β mediated processes in the NAcc have important role...