ISSN:
1573-4919
Keywords:
17β-estradiol
;
endothelium-dependent relaxation
;
acetylcholine
;
rat aorta
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
Abstract We investigated the effects of short-term exposure to low concentrations of 17β-estradiol on vasorelaxation using an in vitro rat thoracic aortic ring preparation. Supraphysiological levels of 17β-estradiol directly relaxed phenylephrine-contracted rings. Although acute incubation (20 min) with 1-100 nM of the female sex hormone did not have any significant effect on phenylephrine-contracted rings, relaxation evoked by acetylcholine was significantly potentiated. In contrast, calcium ionophore A23187-elicited endothelium-dependent relaxation as well as cromakalim- and sodium nitroprusside-mediated endothelium-independent relaxation was unchanged following the same regime with 17β-estradiol. These results demonstrate that short-term treatment with physiologically relevant levels of 17β-estradiol, which on their own have no effect, enhances endothelium-dependent relaxation by acetylcholine. The vascular effects observed herein may partly account for some of the improved acute vasodilatory responses reported with 17β-estradiol on blood flow in humans.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1007090113551
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