Roles of NO-synthase and cyclooxygenase in sex- and pregnancy-dependent arterial and venous pressures in the rat.
The roles of NO synthase (NOS) and cyclooxygenase on vascular pressures were studied as a function of sex and pregnancy. After anesthesia, mean arterial pressure (MAP) and mean circulatory filling pressure were lower in pregnant rats compared with male and virgin rats, but N(G)-nitro-L-arginine methyl ester (L-NAME; 30 mg/kg) induced similar increases in MAP. Pithing abolished these pressure differences, suggesting a diminished autonomic reflex in pregnancy, and led in pregnant rats to a lower arterial and venous NO modulation. In separately perfused mesenteries, the lower responses to KCI observed in venous beds of female compared with male rats do not involve any dysfunction of NOS activity in the mesenteries isolated from virgin and pregnant rats. The cyclooxygenase pathway is implicated in the KCl-induced responses of vessels taken from male rats and of venous mesentery from pregnant rats. But prostanoids do not share in the acetylcholine (ACh)-induced relaxations in the arterial and venous K+-contracted mesenteric vasculatures isolated from any of the groups of rats.
Le Marquer-Domagala
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F
Innothéra, Laboratoire de Pharmacologie, Arcueil, France.
Finet
M
M
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001158:Arteries / Q000502:physiology; D001685:Biological Factors / Q000494:pharmacology; D001794:Blood Pressure / Q000502:physiology*; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000502:physiology*; D011189:Potassium Chloride / Q000494:pharmacology; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000502:physiology*; D011451:Prostaglandin-Endoperoxide Synthases / Q000502:physiology*; D051381:Rats; D012727:Sex Characteristics; D013152:Splanchnic Circulation / Q000187:drug effects / Q000502:physiology; D014690:Venous Pressure / Q000502:physiology
D001685:Biological Factors; D016861:Cyclooxygenase Inhibitors; D004791:Enzyme Inhibitors; C067410:endothelium-dependent hyperpolarization factor; D011189:Potassium Chloride; D019001:Nitric Oxide Synthase; D011451:Prostaglandin-Endoperoxide Synthases; D000109:Acetylcholine; D019331:NG-Nitroarginine Methyl Ester; D007213:Indomethacin