In vivo regulation of vasomotricity by nitric oxide and prostanoids during gestation.
Pharmacological studies using the Doppler technique revealed that pregnancy decreases the systemic blood pressure and enhances uterine blood velocity in rats. The reactivity of the uterine artery to alpha-adrenoceptor and muscarinic receptor agonists was higher than that of systemic arteries. Sodium nitroprusside increased uterine arterial blood velocity slightly during gestation and markedly in non-pregnant rats. N(G)-L-Arginine methyl ester (L-NAME) decreased the uterine blood velocity mainly in gravid animals. The effect of diclofenac on uterine blood velocity was also more pronounced during pregnancy. The actions of sodium nitroprusside, L-NAME and diclofenac on systemic blood pressure were similar in pregnant and virgin rats. Altogether, these results indicate that pregnancy enhances nitric oxide (NO) and vasodilatory prostanoid production in the uterine vascular muscle which becomes less sensitive to exogenous NO. The uterine vasodilated status appears to be determined by conjugated actions of endothelial NO and vasodilator prostanoids of which the synthesis and the effects are weakly modified in systemic arteries during gestation.
Boujedaini
N
N
Department of Pharmacology, INSERM E9920, IFRMP, Rouen University Medical School and Hospital, Rouen, France.
Liu
J
J
Thuillez
C
C
Cazin
L
L
Mensah-Nyagan
A G
AG
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D004008:Diclofenac / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000098:blood supply; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D009599:Nitroprusside / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D011247:Pregnancy; D011453:Prostaglandins / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D012039:Regional Blood Flow / Q000187:drug effects; D014599:Uterus / Q000098:blood supply; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology; D014666:Vasomotor System / Q000187:drug effects / Q000502:physiology*
D004791:Enzyme Inhibitors; D011453:Prostaglandins; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D004008:Diclofenac; D009599:Nitroprusside; D010656:Phenylephrine; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester