Many recent publications incriminate some alteration in the renal circulatory bed as a primary factor in the production and/or maintenance of most states of acute renal insufficiency (1-13). On the one hand, measurements of renal blood flow made by use of the Fick principle either at the onset of the injury or subsequent to an ensuing anuric or oliguric period have shown a significant renal ischemia associated with surgical and hemorrhagic shock, abortion, incompatible blood transfusions, heavy metal poisoning, hemoglobin infusions, and carbon tetrachloride poisoning (1-11). The accuracy of some of these measurements is open to question because of the almost negligible renal extraction of the test substance involved and the difficulties of urine collection during severe oliguria. However, this body of data has been interpreted as indicating that an initial renal ischemia is primarily responsible for the development of renal insufficiency and ultimately anuria produced by all insults not directly nephrotoxic; and that renal ischemia probably is present throughout the period of anuria whatever the initial cause. On the other hand, Trueta Raspall (12), using the results of rabbit experiments, has proposed that the important vascular abnormality is an intrarenal "juxtamedullary shunting" of blood presumably with a normal over-all flow. The continuation of this "shunting" throughout the period of renal inadequacy is implied.Since the "shunt" hypothesis has been widely challenged and the other not yet entirely documented, consideration of these concepts raises cer1This work was supported in part by the National Heart Institute of the U. S. Public Health Service (H 405) and: in part by a University of Pennsylvania Faculty Research Grant.2Research Fellow of the American Heart Association during the tenure of this study. tain related questions: 1) Do intrarenal shunts in the intact subject ever play any part in the development or continuation of renal insufficiency states? 2) Does an initial renal ischemia persist to become a major contributor to the continuation of renal insufficiency or to the commonly associated anuria? With the development of a gas diffusion method for measuring renal blood flow which does not require urine for analysis (14) and with the application of newer arteriographic techniques, more direct and more satisfactory answers can now be given to these questions.In the absence of readily available clinical material, two abnortnal conditions which might simulate those leading to acute anuria in humans were created in dogs: bichloride of mercury poisoning and an incompatible blood transfusion reaction. Then at the time of anticipated maximal urinary suppression, the renal circulatory behavior and tubular function were studied by correlating measurements of renal blood flow, intrarenal distribution of flow, renal para-amino-hippurate (PAH) extraction, and renal arteriovenous oxygen differences with urinary and post mortem renal morphological changes.
METHODSThe two methods of producing renal or urinary t...