An Attempt to Measure Renal Circulation Time With P32

Abstract

In anesthetized, eviscerated dogs and rabbits no consistent relationships were found among renal circulation times as measured simultaneously by Evans blue dye and by P32, arterial blood pressure, renal blood flow and renal vascular resistance. The return of P32 from the kidney following intra-arterial injn. occurred as a protracted wave extending over a considerable time. This was true of the coronary, splenic, femoral, and cephalic circulations as well. The P32 circulation time method provided an objective measure of the shortest vascular route but, in common with the dye method, gave no information bearing on any identifiable physiological factor. Injns. of P32 into individual glomerular capsular spaces in amphibia indicated that some of the protracted return from the kidney may be due to a detour of the P32 into the glomerular filtrate with subsequent tubular reabsorption.