Vasoconstriction and d-amphetamine-induced hypothermia

The hypothermic effect of d-amphetamine was investigated in rats in which vasoconstriction or vasodilation was induced by pharmacological agents: aramine as vasoconstrictor and neprasol as vasodilator. The d-amphetamine-induced hypothermia was enhanced by both drugs among rats kept at 4°C, and both drugs were unable to modify the d-amphetamine-induced hypothermia. These results indicate that although vasoconstriction and vasodilation play a major role in thermoregulation, d-amphetamine-induced hypothermia is not mediated peripherally by vasoconstriction. Since changes in basal metabolic rate, motor activity, food intake and vasoconstriction are not the peripheral mechanisms by which d-amphetamine induced hypothermia, the mechanism is still unknown.