The effect of 17beta-estradiol on isolated omental arteries from preeclamptic women.
OBJECTIVE
To study the effect of 17beta-estradiol on isolated omental arteries from preeclamptic women.


METHODS
Rings of omental artery with intact endothelium were mounted in organ chambers for isometric tension recording. We studied the effect of pharmacological concentrations of 17beta-estradiol on potassium chloride-induced tension and the concentration-contraction relationships for norepinephrine and calcium.


RESULTS
Cumulative application of 17beta-estradiol, in a concentration-dependent manner, relaxed potassium chloride contracted rings. Sixty minutes of incubation with 17beta-estradiol (10(-5)mol/l) attenuated the tension developed in response to potassium chloride, norepinephrine and calcium. Tamoxifen (10(-6)mol/l) did not antagonize the inhibitory actions of 17beta-estradiol.


CONCLUSIONS
Pharmacological concentrations of 17beta-estradiol retain the capability for relaxing omental artery rings from preeclamptic women. The loss of refractoriness to norepinephrine, increased responsiveness to calcium ions and decreased ability of 17beta-estradiol to inhibit calcium-induced tension may be responsible for increased vascular reactivity in preeclampsia.
Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston, TX, USA. yvedernikov@utmb.edu
Y P
YP
Vedernikov
G R
GR
Saade
M A
MA
Belfort
T S
TS
Wen
R E
RE
Garfield
D000328:Adult; D001158:Arteries / Q000187:drug effects; D002118:Calcium / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D020128:Inhibitory Concentration 50; D008875:Middle Aged; D009638:Norepinephrine / Q000494:pharmacology; D009852:Omentum / Q000098:blood supply* / Q000187:drug effects; D011189:Potassium Chloride / Q000494:pharmacology; D011225:Pre-Eclampsia / Q000097:blood*; D011247:Pregnancy; D014662:Vasoconstrictor Agents / Q000494:pharmacology
D014662:Vasoconstrictor Agents; D004958:Estradiol; D011189:Potassium Chloride; D002118:Calcium; D009638:Norepinephrine