[Nitric oxide and isolated aortic contraction in a pregnant hypertension model by the inhibition of nitric oxide synthase in pregnant Wistar rats].
During gestation endothelium induces decreases in vascular responses to vasopressor agents but endothelium disease is followed by hypertension and enhanced vascular reactivity during preeclampsia. In a rat model of preeclampsia induced by NO synthase inhibition we study here isolated aortic contractions. From day 13 of gestation 2 groups of Wistar female rats were fed control (C) or nitro-arginine enriched diets (0.063%, i.e. 30 mg/kg/d) (treated) (T). On gestational day 20 systolic blood pressure (SBP, mmHg) is measured by tail cuff method and isolated thoracic ring aorta contractions are studied after depolarisation (KCl 60 mM) or norepinephrine (cumulative concentrations 10-9 M-10-5 M). After chronic NOS inhibition, hypertension develops: SBP is 154 +/- 2.17 in T and 116 +/- 3.75 in C, p < 0.01 and significant proteinuria (mg/d) appears: T, 63.4 +/- 21.6 versus C 3.08 +/- 0.48, p < 0.01. NO synthase inhibition in treated rats impairs the depressed contractile response obtained in the presence of endothelium in control rats but addition of L-arginine suppresses the effect of nitroarginine. Taking in account our results and those described in literature it appears that L-arginine treatment could ameliorate some pathologic pregnancies.
Dieye
A M
AM
Laboratoire de Pharmacologie et de Physiologie, Faculté de Médecine, de Pharmacie et d'Odonto-Stomatologie, Université Cheikh Anta Diop de Dakar, Sénégal.
Van Overloop
B
B
Faye
B
B
Gairard
A
A
D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects* / Q000503:physiopathology*; D003251:Constriction, Pathologic / Q000503:physiopathology; D004195:Disease Models, Animal; D004353:Drug Evaluation, Preclinical; D004730:Endothelium, Vascular / Q000187:drug effects / Q000503:physiopathology; D005260:Female; D066298:In Vitro Techniques; D009569:Nitric Oxide / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D019335:Nitroarginine / Q000627:therapeutic use*; D009638:Norepinephrine / Q000494:pharmacology; D011225:Pre-Eclampsia / Q000188:drug therapy* / Q000503:physiopathology*; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar; D014662:Vasoconstrictor Agents / Q000494:pharmacology
D014662:Vasoconstrictor Agents; D019335:Nitroarginine; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D009638:Norepinephrine