The effects of different amphetamines on copulatory behaviour and stereotype activity in the female rat, after treatment with monoamine depletors and synthesis inhibitors.

The effects of treatment with alpha-methyl-p-tyrosine (alphaMPT), parachlorophenylalanine (pCPA) and reserpine in combination with D- or L-amphetamine on copulatory behaviour and stereotype activity was studied in estrogen + progesterone treated ovariectomized rats. In doses which clearly prevented D- and L-amphetamine-induced stereotype activity alphaMPT or pCPA did not influence the effect of D- and L-amphetamine on lordosis response. Reserpine treatment decreased the enhanced stereotype activity after D- and L-amphetamine but did not decrease the effect on the copulatory behaviour. Pretreatment with pCPA or reserpine clearly reduced the effect of fenfluramine on the lordosis response. It is suggested that different mechanisms of action are involved in the D-amphetamine effect on the lordosis response and on stereotype activity. The present data give further evidence that the lordosis inhibitory effect of fenfluramine is mediated by 5-HT-mechanisms. The mechanism by which L-amphetamine inhibits the lordosis response seems to be different from both the action of fenfluramine and the effect of D-amphetamine.