[17beta -estradiol induced nitric oxide release in vascular endothelial cells]

Bovine aortic endothelial cells (BAECs) were used to study the effect of 17beta -estradiol (E(2)) on nitric oxide (NO) release, nitric oxide synthase (eNOS) mRNA expression and intracellular free calcium con~cen~tration ([Ca(2+)](I)) and modulation of the effect of E(2) by estrogen receptor (ER) antagonist tamoxifen and NOS inhibitor L-NAME. E(2) (10(-12) 10(-8) mol/L) induced NO release of BAECs in a concentration-dependent manner and the abundant expression of eNOS mRNA in BAECs increased obviously after treatment with E(2) (10(-8)mol/L) for 48 h. These effects were evidently inhibited by tamoxifen (10(-7)mol/L) and L-NAME (10(-6) mol/L). Furthermore treatment with E(2) (10(-8) mol/L) for 48 h significantly increased the resting [Ca(2+)](I) and the rise of [Ca(2+)](I) induced by ATP in BAECs. These results suggest that E(2)-induced NO release and eNOS mRNA expression in BAECs may be mediated by ER and related to calcium mobilization.