Abstract
A reduction of renal arterial pressure in mongrel dogs to 70 mmHg resulted in marked increases in plasma renin activity and plasma levels of angiotensin I (AI) and angiotensin II (AII). Production of renin and AI but not AII in the kidney was observed. A reduction of renal arterial pressure also resulted in a redistribution of blood flow from the outer to inner cortex. An arterial infusion of AII (200 ng/min), however, failed to affect the intrarenal distribution of the blood flow. An intrarenal infusion of AII rather restored the normal pattern of the distribution of intrarenal blood flow altered by the pressure reduction. These results indicate that the renin-angiotensin system is probably not involved in the control of renal hemodynamics through the intrarenal formation of AII, and that the intrarenal hemodynamic changes caused by pressure reduction is due to the intrinsic difference in myogenic force in different cortical zones.
