Estrogen modulation of endothelium-derived relaxing factors by human endothelial cells
Biochemical and Biophysical Research Communications
We report the modulatory effects of estrogen on release of endothelium-derived relaxing factors (EDRFs) in a human endothelial cell line, EA.hy926. Using bioassay, we showed that EA.hy926 released EDRF including nitric oxide (NO) and endothelium-derived hyperpolarizing factor (EDHF) measured by relaxation of pre-contracted endothelium-denuded rabbit aortic rings. This EDRF production was significantly higher in cells treated for 24 h with 17-β-estradiol (10 mol/L) than control cells. Addition of l-NAME to the perfusate of cells caused the relaxation induced by the endothelial cell perfusate to become transient and abolished the enhancement of relaxation due to estrogen treatment. Addition of K channel blockers to the perfusate abolished the l-NAME-resistant relaxation of the bioassay ring. Using real-time PCR, we demonstrated that eNOS expression in estrogen-treated cells was significantly higher than controls. These results show that estrogen exerts a potentially important vasculo-protective effect by stimulating NO but not EDHF production. © 2004 Elsevier Inc. All rights reserved. -6 Ca
Van Breemen, C.
Estrogen modulation of endothelium-derived relaxing factors by human endothelial cells.
Biochemical and Biophysical Research Communications, 322(2), 373–379.