Dopamine-stimulated adenylate cyclase in hypothalamus: influence of estrous cycle in female and castration in male rats.

The activity of dopamine- and norepinephrine-stimulated adenylate cyclase in hypothalamus and amygdala was studied during the estrous cycle of the female and following castration of the male rat. In the medial hypothalamus but not in the anterior hypothalamus or amygdala, stimulation of adenylate cyclase by dopamine was enhanced during proestrus and following castration. There were no changes in norepinephrine-stimulated adenylate cyclase in medial hypothalamus. Thus, an interaction may exist between gonadal hormones and dopamine receptors linked to adenylate cyclase in medial hypothalamus. The rapidity of the changes in receptor sensitivity suggests that this interaction plays an important role in physiological regulation.