Summary.

Main pharmacological effects of caffeine are mediated by its blockade of adenosine receptors. Recent experimental data suggest involvement of purinergic mechanisms in the regulation of body temperature. The present study determined the effects of caffeine on the core body temperature in rats at ambient temperature of 22 Ѓ} 1oC. We investigated the changes of core body temperature in male Wistar rats after systemic (i.p.) administration of caffeine on the two experimental animal groups: (1) normal rats; (2) rats with experimental model of depression. Lower doses of caffeine (2, 20 and 40 mg/kg) produced a significant and dose-dependent rise of body temperature in rats from both experimental groups. The hyperthermic effect in normal rats was observed soon after application of caffeine and lasted about 90 min. The hyperthermic effect in rats with experimental model of depression was also observed soon after application of caffeine and lasted about 150 min. High dose of caffeine (100 mg/kg) induced significant hypothermia between 90th and 150th min in normal rats and hyperthermia between 30th and 60th min in rats with experimental model of depression.