Effect of reserpine on body temperature in the rat after pretreatment with amphetamine and monoamineoxidase inhibitors.

Intravenous injection of reserpine produced a small but significant hyperthermic effect which is followed by a persistent decrease in temperature. Amphetamine, tranylcypromine and pargyline administered intraperitoneally caused a fall in body temperature. The decrease was higher after pargyline than after amphetamine and tranylcypromine. The initial increase in temperature that was seen immediately after reserpine administration in unanaesthetized and anaesthetized rats was significantly potentiated in the animals pretreated with amphetamine and monoamineoxidase (MAO) inhibitors. The decrease in temperature occurring afterwards is not significantly different from that seen after reserpine alone in conscious rats. However, in anaesthetized rats the hypothermic response was delayed and was not as marked as in conscious animals. The changes in the transient hyperthermic response to reserpine obtained with pretreatment with these drugs are roughly reminiscent of the modification of the effect on blood pressure. In conclusion, the present results confirm that the simple and objective determination of drug induced changes on reserpine effects on temperature may equal the results obtained on blood pressure.