Characteristics of blood flow in branches of the renal artery

¹ Department of Physiology, University of Minnesota, Minneapolis, Minnesota

A semi-isolated arterial blood-perfused dog kidney preparation was used to study autoregulation in two primary branches of the renal artery simultaneously. Autoregulative resistance changes were nearly completely limited to the specific arterial branch in which the perfusion pressure was changed. The other arterial branch inflow kept at nearly constant perfusion pressure showed very little if any change. The effects of vasoactive drugs were likewise restricted to the specific portion of the arterial bed into which they were injected. When only one branch of the renal artery was clamped off, the pressure in it fell to about 12 mm Hg indicating that there is little effective arterio-arterial cross anastomosis. Blood draining in a retrograde direction from one branch artery opened to the atmosphere was similar in composition to arterial blood in that it did not show evidence of the extraction of test substances that was occurring in the perfused portion of the kidney.

Key Words: Autoregulation • arterial cross anastomoses • Kidney capsule • perfused kidney • vasoactive drugs • kidney vascular bed

Submitted on May 9, 1963