Endothelium-derived relaxing factor and cyclic GMP-dependent vasorelaxation in human chorionic plate arteries.
Endothelium derived relaxing factor (EDRF), now widely believed to be nitric oxide (NO), may play an important part in the control of fetoplacental vascular tone. To further explore this role we have determined the relaxation responses to exogenous NO and examined the temporal relationship between intracellular concentrations of cyclic GMP and vascular tone in isolated ring segments of human chorionic plate arteries. We have also determined the dose relations for the contractile agonists serotonin and the thromboxane analog U46619. Lastly, we have explored the relaxation responses to a wide range of agents known to elicit EDRF release in other vascular beds. Chorionic plate arteries relaxed significantly to exogenous NO with concomitant increases in cyclic guanosine monophosphate over basal values. ED50s for serotonin and U46619 were 1.48 x 10(-6) M and 3.39 x 10(-8) M respectively. The ED50 for NO derived from S-nitroso-N-acetyl-penicillamine was 1.28 x 10(-6) M. Endothelium-intact segments of chorionic plate arteries pre-contracted with either serotonin or U46619 failed to relax significantly to acetylcholine, adenosine diphosphate, A23187, bradykinin, and histamine and only minimally to substance P. We suggest that EDRF is likely to be important in the control of placental vascular tone, but that it is not possible to demonstrate its action in an unperfused experimental system.
Hull
A D
AD
Department of Obstetrics and Gynecology, Loma Linda University School of Medicine, California 92350.
White
C R
CR
Pearce
W J
WJ
D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D000109:Acetylcholine / Q000494:pharmacology; D001158:Arteries / Q000187:drug effects / Q000502:physiology; D001920:Bradykinin / Q000494:pharmacology; D000001:Calcimycin / Q000494:pharmacology; D002823:Chorion / Q000098:blood supply*; D000242:Cyclic AMP / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology; D005260:Female; D006632:Histamine / Q000494:pharmacology; D006801:Humans; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects; D009569:Nitric Oxide / Q000494:pharmacology*; D011247:Pregnancy; D011450:Prostaglandin Endoperoxides, Synthetic / Q000494:pharmacology; D012701:Serotonin / Q000494:pharmacology; D013373:Substance P / Q000494:pharmacology; D013928:Thromboxane A2 / Q000031:analogs & derivatives / Q000494:pharmacology; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects*
D011450:Prostaglandin Endoperoxides, Synthetic; D014662:Vasoconstrictor Agents; D009569:Nitric Oxide; D012701:Serotonin; D013373:Substance P; D000001:Calcimycin; D013928:Thromboxane A2; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D006632:Histamine; D000242:Cyclic AMP; D006152:Cyclic GMP; D000109:Acetylcholine; D001920:Bradykinin