Inhibition of "wet shakes" during morphine abstinence by an antagonist of opiate analgesia.

An antagonist of morphine analgesia, N-cyclopropylmethylnorazidomorphine (CAM) inhibited the"wet shakes" appearing during spontaneous or nalorphine-precipitated morphine abstinence. CAM inhibited the pinna reflex more strongly than did morphine and selectively antagonized quipazine-induced head twitches; its inhibition of head twitches induced by 5-hydroxytryptophan or LSD seemed unspecific. The results suggest that the opiate receptors involved in the inhibition of some symptoms of morphine abstinence and of the pinna reflex differ from those involved in opiate analgesia.