Estrogen-induced efflux of endogenous catecholamines from the hypothalamus in vitro

Short-term organ cultures of the intact hypothalamus were used to study the effects of various estrogenic compounds on catecholamine release. Estradiol-17ß (0.1-20 μM) produced a concentration-dependent efflux of norepinephrine and dopamine while its biologically inactive enantiomer, estradiol-17α, was ineffective at concentrations up to 20 μM. Diethylstilbestrol, a potent non-steroidal estrogen, was as effective as estradiol-17ß in inducing catecholamine efflux. In contrast, weakly or non-estrogenic steroids such as estrone, estriol, and corticosterone were without effect. The time course of the estrogen-induced efflux of hypothalamic catecholamines was similar to that previously reported for the estrogen-induced accumulation of hypothalamic cAMP, providing further evidence for the involvement of catecholamines in this effect. These results suggest that estrogen may facilitate the release of catecholamines within the hypothalamus.