Effects of Postpuberal Castration on Dopamine Receptor Sensitivity in the Male Rat Brain

Abstract

In order to study the effects of castration of brain dopamine @A) receptor sensitivity, the effects of apomorphine on locomotor activity and striatal DA synthesis, as assessed by the dihydroxyphenylalanine (DOPA) accumulation after NSD-1015 treatment, were examined in normal and castrated male Sprague-Dawley rats pretreated with reserpine (5 mg/ kg - 18 hrs). There was an enhanced locomotor response to apomorphine (0.05-0.1 mg/kg) in castrated animals, as compared to sham operated controls. Furthermore, the increase in DOPA accumulation produced by the reserpine treatment was antagonized to a greater extent by apomorphine in the castrated animals. These results indicate an enhanced DA receptor sensitivity at both pre- and post-synaptic sites.