Effects of atrial natriuretic peptide and cyclic guanosine monophosphate on isolated human myometrial arteries preconstricted by endothelin-1.
In the present in vitro study we investigated the possible vasorelaxing effect of atrial natriuretic peptide (ANP) and cyclic guanosine monophosphate (cGMP) on small intramyometrial arteries precontracted by endothelin-1 (ET-1). Myometrial biopsies from normotensive pregnant women were obtained during cesarean section and arteries of resistance vessel size were dissected and mounted in a tissue chamber for isometric registration of contractile tone. In arteries preconstricted with ET-1 (10(-8)M), ANP produced a concentration-dependent relaxation of 19 +/- 5% (mean +/- SEM) and 27 +/- 7% at concentrations of 10(-7) and 3 x 10(-7) M, respectively. cGMP induced a relaxation of 13 +/- 2, 18 +/- 3, 25 +/- 4 and 30 +/- 7% at concentrations of 10(-5), 10(-4), 3 x 10(-4) and 10(-3) M, respectively. Pretreatment with ANP did not attenuate the contraction produced by ET-1. We suggest that ANP may have a vasodilating effect on preconstricted human uteroplacental vessels. It also provides evidence for the role of other endogenous or exogenous vasodilators acting via cGMP-dependent mechanisms in the counteraction of ET-1-induced contraction of the myometrial resistance vessels during pregnancy.
Department of Obstetrics and Gynecology, Karolinska Institute, Huddinge University Hospital, Sweden.
K R
KR
Kublickiene
C
C
Grunewald
M
M
Kublickas
B
B
Lindblom
N O
NO
Lunell
H
H
Nisell
D001158:Arteries / Q000187:drug effects* / Q000502:physiology; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D002585:Cesarean Section; D006152:Cyclic GMP / Q000494:pharmacology*; D016232:Endothelins / Q000494:pharmacology*; D005260:Female; D006801:Humans; D009215:Myometrium / Q000098:blood supply*; D011247:Pregnancy; D014661:Vasoconstriction / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects
D016232:Endothelins; D009320:Atrial Natriuretic Factor; D006152:Cyclic GMP