Autoregulation of renal blood flow during the infusion of acetylcholine or carbachol in anaesthetized dogs

Abstract

Abstract Whether renal blood flow autoregulation is abolished by acetylcholine was re-examined by kidney perfusion experiments in anaesthetized dogs. Renal blood flow was dose-dependently increased by the renal arterial infusion of acetylcholine (2 and 5 μg min−1) or another muscarinic agent, carbachol (2 and 5 μg min−1) and was maintained at an increased level during the infusion. When perfusion pressure was changed stepwise between 60 and 200 mmHg, the infusion of acetylcholine or carbachol caused no impairment of autoregulation. It is concluded that autoregulation is independent of muscarinic stimulation of vascular smooth muscle in the kidney.