Failure of apomorphine to induce dopamine receptor hypersensitivity.

Apomorphine, a direct dopamine agonist, failed to induce the so called dopamine receptor supersensitivity. Furthermore, a review of the evidence strongly suggests that the mechanisms involved in this phenomenon are not purely dopaminergic. This phenomenon is more complex than one of simple changes in the sensitivity or number of a particular type of receptor. Also sexual differences were observed and the literature suggest an involvement of serotoninergic mechanisms in sterotyped behavior.