Hypotensive effect of chronic intrarenal infusion of acetylcholine during angiotensin hypertension.
We examined the role of the pressure natriuresis phenomenon in long-term arterial pressure control. Uninephrectomized dogs were housed in metabolic cages and made hypertensive with a continuous background intravenous infusion of angiotensin II (AngII, 12 ng/kg/min). To increase the ability of the kidney to excrete salt and water, we infused acetylcholine (ACH, 2.0 micrograms/kg/min), a potent natriuretic agen, directly into the renal artery. In four dogs, ACH decreased mean arterial pressure (MAP) from 144 +/- 5 mm Hg to 113 +/- 3 mm Hg. Sodium excretion increased by about 60% on the first day of infusion and then returned rapidly toward the control value. On cessation of the ACH infusion, there was a transient but marked sodium retention, and the hypertension returned. A control infusion of ACH intravenously rather than into the renal artery in the same four dogs did not affect MAP or sodium excretion during AngII hypertension.
Montani
J P
JP
Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson 39216-4505.
Adair
T H
TH
Nuwayhid
B S
BS
Guyton
A C
AC
D000109:Acetylcholine / Q000008:administration & dosage / Q000494:pharmacology*; D000804:Angiotensin II; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D004231:Diuresis / Q000187:drug effects; D004285:Dogs; D006973:Hypertension / Q000139:chemically induced / Q000188:drug therapy*; D007022:Hypotension / Q000139:chemically induced*; D007261:Infusions, Intra-Arterial; D009318:Natriuresis / Q000187:drug effects; D012077:Renal Artery
D000804:Angiotensin II; D000109:Acetylcholine