Loss of endothelium-dependent relaxation in myometrial resistance arteries in pre-eclampsia.
OBJECTIVE
To measure endothelium-dependent relaxation in myometrial resistance arteries and to compare this parameter in nonpregnant and normotensive pregnant women and those with pregnancies complicated by pre-eclampsia.


METHODS
A prospective study.


METHODS
Nottingham City Hospital.


METHODS
Thirty-seven nonpregnant women undergoing hysterectomy and 51 pregnant women undergoing caesarean section, of whom there were 39 normotensive and 12 with pre-eclampsia.


METHODS
Resistance arteries, dissected from myometrial biopsies, were mounted on a wire myograph and preconstricted with vasopressin then subjected to incremental doses of bradykinin.


RESULTS
Endothelium-dependent relaxation to bradykinin was seen in the vessels of nonpregnant and normotensive pregnant women. Markedly reduced endothelium-dependent relaxation was found in the myometrial arteries from women with pre-eclampsia when compared with both nonpregnant (P < 0.0001) and normotensive pregnant (P < 0.0001) women.


CONCLUSIONS
A significant loss of endothelium-dependent relaxation in myometrial resistance arteries in pre-eclampsia may contribute to the altered vasoreactivity seen in pre-eclampsia, and particularly to the decreased placental perfusion and fetal growth retardation commonly associated with this condition.
Ashworth
J R
JR
Department of Obstetrics and Gynaecology, Nottingham City Hospital, UK.
Warren
A Y
AY
Baker
P N
PN
Johnson
I R
IR
D000328:Adult; D001158:Arteries / Q000187:drug effects / Q000503:physiopathology; D001920:Bradykinin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000502:physiology*; D005260:Female; D006801:Humans; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D009213:Myography; D009215:Myometrium / Q000098:blood supply*; D009638:Norepinephrine / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D011225:Pre-Eclampsia / Q000503:physiopathology*; D011247:Pregnancy; D011446:Prospective Studies; D014655:Vascular Resistance / Q000187:drug effects*; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014667:Vasopressins / Q000494:pharmacology
D014662:Vasoconstrictor Agents; D014667:Vasopressins; D011188:Potassium; D001920:Bradykinin; D009638:Norepinephrine