Effect of steroid hormones and antihormones on hypothalamic beta-endorphin concentrations in intact and castrated female rats.

The aim of the present study was to evaluate the effects of estrogens and androgens on hypothalamic beta-endorphin (beta-EP) concentrations. Intact or castrated female rats were chronically (2 weeks) treated with estrogen (estradiol benzoate) and/or antiestrogens (clomiphene, cyclophenil or epimestrol), and with androgens (dihydrotestosterone or dehydroepiandrosterone sulphate) and/or antiandrogen (cyproterone acetate). A group of rats treated with vehicle were studied as comparison.

Norgestimate increases pituitary and hypothalamic concentrations of immunoreactive beta-endorphin.

Progesterone is a potent hormone acting on the female reproductive tract and influencing a series of other functions. Recent studies revealed a correlation between progesterone and brain neurotransmitters and neuropeptides. Our study evaluated the possible effect of norgestimate, a new progestin, on hypothalamic and pituitary beta-endorphin (B-EP) concentration in castrated female rats.