Abstract
Rat kidneys were perfused in vitro with Perfadex (Gelin's solution) and a modified Collins' C3-solution with or without colloids. When the same flow rate was used the presence of 5% dextran 40, 5% albumin, or 10% albumin did not alter the clearing of 51Cr-tagged red blood cells. The main difference between the experimental groups was a significant increase in perfusion pressure when colloids were excluded from the perfusate. Results concerning the regional distribution of 51Cr-activity within the kidney are discussed.