Activation with (+/-)N-n-propyl-nor-apomorphine (NPA) of the male rat copulatory behavior.

I.p. (+/-)N-n-propyl-nor-apomorphine HCl (NPA) influences copulatory behavior of vigorous adult male rats in the same ways as apomorphine, i.e., it reduces the latency to ejaculation as well as mount and intromission frequency. Furthermore, NPA administered to impotent male rats restores normal mating behavior in some of them.