Abnormal endothelial cell function of resistance arteries from women with preeclampsia.
OBJECTIVE
There is substantial indirect evidence that the vascular endothelium may be dysfunctional in preeclampsia and that reduced production of endothelial-derived vasodilators may account for the increased vascular resistance and enhanced pressor sensitivity characteristic of this disorder. In this study we directly investigated endothelial function by examining acetylcholine-mediated relaxation in small arteries dissected from the subcutaneous fat layer examined at the time of cesarean section.


METHODS
By means of a small vessel myograph we measured tension in resistance arteries of normal pregnant women (n = 12) and women with preeclampsia (n = 12) and assessed the contributions of vasodilatory prostanoids and endothelium-derived relaxing factor to endothelium-dependent relaxation, as elicited by acetylcholine, 1 nmol/L to 10 mumol/L, after precontraction with 3 mumol/L norepinephrine.


RESULTS
Endothelium-dependent relaxation was impaired in arteries of women with preeclampsia compared with arteries from normotensive pregnant women. Endothelium-independent relaxation as assessed by sodium nitroprusside was not altered in the arteries from preeclamptic women.


CONCLUSIONS
This study provides direct evidence of abnormal endothelial function in preeclampsia. No deficiency in endothelium-independent relaxation could be detected.
McCarthy
A L
AL
UMDS Smooth Muscle Group, Sherrington School of Physiology, Guy's Hospital, London, England.
Woolfson
R G
RG
Raju
S K
SK
Poston
L
L
D000109:Acetylcholine / Q000494:pharmacology; D000328:Adult; D000594:Amino Acid Oxidoreductases / Q000037:antagonists & inhibitors; D001158:Arteries / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D004730:Endothelium, Vascular / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D009569:Nitric Oxide / Q000502:physiology; D019001:Nitric Oxide Synthase; D009599:Nitroprusside / Q000494:pharmacology; D011225:Pre-Eclampsia / Q000473:pathology / Q000503:physiopathology*; D011247:Pregnancy; D011453:Prostaglandins / Q000502:physiology
D011453:Prostaglandins; D009599:Nitroprusside; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases; D000109:Acetylcholine; D007213:Indomethacin