Effect of an increased cardiac output on vascular responses to vasoactive agents in two-kidney, one-clip Goldblatt hypertension.
The effect of the increased cardiac output of two-kidney, one-clip Goldblatt hypertension (2-KGH) on the altered vascular responses to vasoactive agents was examined in the conscious, chronically instrumented dog. The early stage of 2-KGH is characterized by an increased arterial pressure, an increased aortic flow, a decreased total peripheral resistance, and enhanced responses to angiotensin II and serotonin. As the aortic flow increases the responses to norepinephrine are enhanced, and the dilator responses to acetyl-choline and nitroglycerin are depressed. Aortic flow then returns to control values and the increased arterial pressure is maintained by an increase in peripheral resistance. When the increased aortic flow is prevented by occluding the vena cava to maintain flow at control values, the vascular responses to each of the agonists do not differ from that obtained when the aortic flow is elevated. Moreover, the temporal development and magnitude of the elevation in arterial pressure resulting from the increased vascular resistance is similar in dogs with an increased and normal aortic flows. The results suggest that increased aortic flow is not essential for the increased vascular resistance or the vascular changes in the canine model of 2-KGH.
D000109:Acetylcholine / Q000494:pharmacology; D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D004195:Disease Models, Animal; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D011464:Epoprostenol / Q000494:pharmacology; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006977:Hypertension, Renal / Q000503:physiopathology*; D006978:Hypertension, Renovascular / Q000503:physiopathology*; D008297:Male; D005996:Nitroglycerin / Q000494:pharmacology; D009638:Norepinephrine / Q000494:pharmacology; D012701:Serotonin / Q000494:pharmacology; D014655:Vascular Resistance / Q000187:drug effects*; D014662:Vasoconstrictor Agents / Q000494:pharmacology*; D014665:Vasodilator Agents / Q000494:pharmacology*
D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D000804:Angiotensin II; D012701:Serotonin; D011464:Epoprostenol; D005996:Nitroglycerin; D000109:Acetylcholine; D009638:Norepinephrine