Estradiol reduces calcium currents in rat neostriatal neurons via a membrane receptor.

摘要: Until recently, steroid hormones were believed to act only on cells containing intracellular receptors. However, recent evidence suggests that steroids have specific and rapid effects at the cellular membrane. Using whole-cell patch-clamp techniques, 17 beta-estradiol was found reduce Ba2+ entry reversibly via Ca2+ channels in acutely dissociated cultured neostriatal neurons. The sex-specific, i.e., reduction of currents greater neurons taken from female rats. beta-Estradiol primarily targeted L-type currents, their inhibition detected reliably within seconds administration. maximum by occurred picomolar concentrations. conjugated bovine serum albumin also reduced suggesting effect occurs membrane surface. Dialysis with GTP gamma S prevented reversal modulation, acts G-protein activation. alpha-Estradiol but significantly less effective than beta-estradiol. Estriol 4-hydroxyestradiol similar efficacy beta-estradiol, whereas estrone 2-methoxyestriol effective. Tamoxifen did not occlude These results suggest physiological concentrations, can immediate actions nongenomic signaling pathways.