Influence of estrogens on tuberoinfundibular and striatal dopaminergic systems in the rat.

As assessed by changes of prolactin secretion in rat anterior pituitary cells in culture, estrogens can exert a potent antidopaminergic activity at the pituitary level. Androgens and progestins can reverse the effect of estrogens. An interaction of sex steroids at the hypothalamic level on dopamine release and at the pituitary level on dopamine action could also be demonstrated in vivo. Moreover, estrogens exert a similar antidopaminergic activity at the striatal level on dopaminergic-agent-induced acetylcholine accumulation. The observation of a modulation by estrogens of the symptoms of Parkinson's disease and tardive dyskinesias suggests the implication of sex steroids in neurology, psychiatry and behavior.