Estrogen replacement enhances EDHF-mediated vasodilation of mesenteric and uterine resistance arteries: role of endothelial cell Ca^sup 2

• Published in: American journal of physiology: endocrinology and metabolism Vol. 296; no. 3; p. E503
• Main Authors: Burger, Natalie Z, Kuzina, Olga Y, Osol, George, Gokina, Natalia I
• Format: Journal Article
• Language: English
• Published: Bethesda American Physiological Society 01.03.2009
• Subjects: Blood vessels; Cells; Endocrinology; Estrogens; Rodents; Signal transduction; Small intestine; Studies
• ISSN: 0193-1849; 1522-1555

Endothelium-derived hyperpolarizing factor (EDHF) plays an important role in the regulation of vascular microcirculatory tone. This study explores the role of estrogen in controlling EDHF-mediated vasodilation of uterine resistance arteries of the rat and also analyzes the contribution of endothelial cell (EC) ... signaling to this process. A parallel study was also performed with mesenteric arteries to provide comparison with a nonreproductive vasculature. Mature female rats underwent ovariectomy, with one half receiving 17β-estradiol replacement (OVX+E) and the other half serving as estrogen-deficient controls (OVX). Uterine or mesenteric resistance arteries were harvested, cannulated, and pressurized. Nitric oxide and prostacyclin production were inhibited with 200 ...M N...-nitro-L-arginine and 10 ...M indomethacin, respectively. ACh effectively dilated the arteries preconstricted with phenylephrine but failed to induce dilation of vessels preconstricted with high-K+ solution. ACh EC... values were decreased by estrogen replacement by five- and twofold in uterine and mesenteric arteries, respectively. As evidenced by fura-2-based measurements of EC cytoplasmic ... concentration (...), estrogen replacement was associated with increased basal and ACh-stimulated EC [...]... rise in uterine, but not mesenteric, vessels. These data demonstrate that EDHF contributes to endothelium-dependent vasodilation of uterine and mesenteric resistance arteries and that estrogen controls EDHF-related mechanism(s) more efficiently in reproductive vs. nonreproductive vessels. Enhanced endothelial ... signaling may be an important underlying mechanism in estrogenic modulation of EDHF-mediated vasodilation in small resistance uterine arteries. (ProQuest: ... denotes formulae/symbols omitted.)