Responses to exogenous adenosine 3',5'-monophosphate of cardiac output and blood flow in the renal, superior mesenteric and carotid arteries in anesthetized dogs.

Abstract

Changes in the cardiac output and blood flow in the renal, superior mesenteric and carotid arteries in anesthetized dogs were observed, using the non-cannulating electromagnetic flow meter. Dibutyryl cyclic-AMP, 5 mg/kg body weight, was given intravenously and the following results were obtained: 1) Dibutyryl cyclic-AMP increased the stroke volume and the cardiac output, and slightly increased the heart rate. These effects appeared 3 to 5 min after administration of dibutyryl cyclic-AMP. 2) The mean systemic blood pressure as well as the central venous pressure fell slightly. 3) The renal and the superior mesenteric artery blood flow increased markedly, but the carotid artery blood flow did not change. 4) Distribution of the cardiac output to the renal and superior mesenteric arteries did not change but distribution to the carotid artery decreased. 5) Total peripheral resistance, renal artery vascular resistance and superior mesenteric artery vascular resistance decreased, and carotid artery vascular resistance decreased slightly. 6) The cardiac output and blood flow were enhanced by aminophylline (3 mg/kg), and were not blocked by propranolol (0.3 mg/kg).