Effects of sex hormones on NO release from endothelial cell in human vena umbilicalis

Aim: To explore the influence of individual or combined use of sex hormones on NO release from endothelial cells in human vena umbilicalis. Methods: Primary endothelial cells in human vena umbilicalis were cultured, and the NO 2 contents in culture solution were determined by enzyme process. Results: In comparison with controls, NO contents significantly increased when 17β-estradiol ( 0.001 μmol / L, 0.1 μmol / L, and 10 μmol / L) were administered to the endothelial cells for 10 min and 30 min, respectively (P0.05), but treatment with 17β-estradiol for 60 min caused no significant changes of NO (P0.05). Combined with progesterone ( 0.001 μmol / L, 0.1 μmol / L, and 10 μmol / L), the effects of 17β-estradiol on the NO release from endothelial cells were markedly inhibited(P0.05). The actions of progesterone and testosterone on the NO release from endothelial cells were different with different concentrations and time of administration. Concluson: 17β-estradiol dilates the blood vessel,which may act via mechanism of affecting the release of nitric oxide from endothelium cells.When 17β-estradiol and progesterone are combinedly used,progesterone inhibits the effect of estradiol on the vasodilatation possibly by inhibiting the release of NO