高血圧における臓器循環に関する研究 ： 心房性ナトリウム利尿ペプチド投与の影響

Abstract

The effects of α-hANP on systemic and renal hemodynamics including renal cortical blood flow (CBF) and renal function, were observed in mongrel dogs (N=22) which were divided into the normotensive group (N=10 dogs) and the hypertensive group (N=12 dogs). The right renal artery was narrowed under intraperitoneal anesthesia with pentobarbital in the hypertensive group to make up renovascular hypertension. Electrodes of an electrolytic tissue blood flow meter were inserted into the inner and outer cortical layers of the left kidney. In addition, a Swan-Ganz catheter and a catheter for arterial blood pressure determination were inserted into the pulmonary artery and the origin of the Aorta. After stabilization of hemodynamics, α-hANP (0.1 μg/kg or 2.5 μg/kg) was given via the cubital vein into the animals. Results were as follows : heart rate (HR) did not change remarkably, mean aortic blood pressure (MBP) was remarkably reduced in both groups after high dose treatment. The degree of change was significantly greater in the hypertensive group than in the normotensive group. Cardiac output (CO) initially increased and decreased slowly after high dose treatment. Renal blood pressure (RBP) was reduced significantly in both groups after high dose treatment. Renal blood flow (RBF) increased significantly in the hypertensive group after high dose treatment. Glomerular filtration rate (GFR) and urinary volume (UV) increased in both groups, but the degree of change was greater in the hypertensive group than in the normotensive group upon high dose treatment. Plasma renin activity (PRA) and plasma aldosteron concentration (ALD) decreased effectively upon high dose treatment. In the hypertensive group, renal cortical blood flow increased effectively, but otherwise in normotensive group. The increase of CBF upon high dose treatment seems to be associated with reduced PRA. Upon high dose, the distribution of RBF was greater in the hypertensive group.