The cortical and medullary blood flows of the isolated dog's kidney.

Since TRUETA and associates (1947) published that under certain experimental conditions there might be a deviation in the distribution of blood through the cortex and medulla of the kidney several investigators have reported that the cortical and medullary blood flows behave differently. For example: a) CARGIL (1948) reported that during the intravenous administration of serum albumin the flow through the medullary circuit increased in a higher magnitude than the cortical flow, b) KRAMER et al .(1960) found that during a sudden rise in the perfusion pressure, the blood flow through the medullary circuit increased while the cortical and total renal blood flow remained constant, c) THURAU at al.(1960) showed that the medullary flow increased proportionately more than the cortical flow during osmotic diuresis and finally d) PILKINGTON et al.(1965) have shown that acetylcholine (50-80 ƒÊ moles/min) injected into the renal artery produced a greater increase in the medully flow than in the cortical flow. The latter authors also reported that norepinephrine reduced cortical flow markedly, while medullary flow was not significantly changed. In the present study we are reporting further evidences which show that in the kidney the cortical and medullary blood flows behave differently.