Functional characteristics of chorionic plate placental arteries from normal pregnant women and women with pre-eclampsia.
OBJECTIVE
We aimed to compare placental small artery function from women with pre-eclampsia and normal pregnancy. In particular, we wished to test the hypothesis that these arteries respond differently to an endothelium-dependent vasodilator, to the presence of nitric oxide, and to the presence of cyclic monophosphate nucleotides.


METHODS
A small vessel wire myograph was used to study placental arteries (200 to 550 microm). Contractile function was assessed with vasopressin. Relaxation was assessed with the endothelium-dependent vasodilator, bradykinin, and the endothelium-independent vasodilators sodium nitroprusside (a nitric oxide donor) and papaverine (a phosphodiesterase inhibitor).


RESULTS
The constrictor response to vasopressin did not differ between patient groups (p=0.79; repeated measures ANOVA). For both normal pregnancy and pre-eclampsia, the response of pre-constricted arteries to the endothelium-dependent vasodilator, bradykinin, was minimal. Vasorelaxation to sodium nitroprusside and papaverine was attenuated in pre-eclampsia compared to normal pregnancy (p=0.03 and p<0.001, respectively; repeated measures ANOVA).


CONCLUSIONS
In pre-eclampsia, placental arteries exhibit an attenuated vasodilatory response to nitric oxide.
Ong
Stephen S
SS
The MRC Development Group, School of Human Development, University of Nottingham, City Hospital, Nottingham NG5 1PB, UK. stephen.ong@btinternet.com
Crocker
Ian P
IP
Warren
Averil Y
AY
Baker
Philip N
PN
D000328:Adult; D000704:Analysis of Variance; D001158:Arteries / Q000502:physiology / Q000503:physiopathology; D001920:Bradykinin / Q000494:pharmacology; D002823:Chorion / Q000098:blood supply*; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology*; D005260:Female; D006801:Humans; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology; D009569:Nitric Oxide / Q000502:physiology; D009599:Nitroprusside / Q000494:pharmacology*; D010208:Papaverine / Q000494:pharmacology*; D010920:Placenta / Q000098:blood supply*; D011225:Pre-Eclampsia / Q000503:physiopathology*; D011247:Pregnancy / Q000502:physiology*; D018709:Statistics, Nonparametric; D014655:Vascular Resistance / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology*; D014667:Vasopressins / Q000494:pharmacology
D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D014667:Vasopressins; D009599:Nitroprusside; D009569:Nitric Oxide; D010208:Papaverine; D001920:Bradykinin