title: Vascular reactivity to angiotensin II in the normotensive and hypertensive pregnant ewe.
abstract: The circulatory responses to progressively increasing doses of angiotensin II were studied in the same group of chronically instrumented unanesthetized pregnant sheep during three consecutive periods: a) normotensive with intact kidneys; b) normotensive with unilateral nephrectomy; and c) one-kidney hypertension. The results show that 1) the pressor response to a given dose of angiotensin was significantly greater in the normotensive than in the hypertensive condition; 2) uterine blood flow decreased markedly with the development of hypertension; 3) uterine circulatory response to angiotensin depended on the dosage; the response was less the the hypertensive than in the normotensive condition; 4) renal blood flow decreased and renal vascular resistance increased during angiotensin infusion, but the response was less in the hypertensive than in the normotensive condition; the response of the renal circulation decreased with increasing doses of angiotensin. These observations suggest a generalized vascular refractoriness to exogenous angiotensin II in the pregnant ewe with experimental renal hypertension.
mesh_terms: D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005260:Female; D006977:Hypertension, Renal / Q000503:physiopathology*; D007668:Kidney / Q000098:blood supply*; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000503:physiopathology*; D011270:Pregnancy, Animal; D012039:Regional Blood Flow / Q000187:drug effects; D012756:Sheep / Q000502:physiology; D014599:Uterus / Q000098:blood supply*; D014655:Vascular Resistance / Q000187:drug effects
chemical_list: D000804:Angiotensin II