EXPERIMENTS ON THE PATENCY OF THE BLOOD VESSELS OF NEPHRITIC KIDNEYS OBTAINED AT AUTOPSY

One of the first questions which arise in the study of the physiology of the diseased kidney concerns the capacity of its vessels to permit a normal blood flow. If this capacity is normal, alterations in renal function must be attributed either to extrarenal factors, to functional rather than structural changes in renal vessels, or to changes in the renal parenchyma. If conditions in the kidney preclude a normal blood flow, completely normal function is impossible and the basis for interpreting certain types of urinary abnormality has been disclosed. The experiments described here were undertaken in the hope of distinguishing those types of kidney disease in which a mechanical, anatomic obstruction to blood flow exists from those in which the structural condition of the vessels may be believed to permit a normal blood flow. Study of changes in the renal vessels in disease by other than histological methods is by no means new. Evidence of the capacity of the diseased kidney to transmit blood has been sought in measurements of blood flow after experimental renal injury, in roentgenograms of injected kidneys, and in perfusion of isolated organs. The design of the present experiments involved a combination of the last two methods, namely, measurement of the outflow from the renal vein during perfusion under constant conditions, and correlation of this flow with roentgenograms of the vessels after injection, and with histological sections. Direct measurements of renal blood flow in experimental disease have been confined to acute injury. Tribe, Hopkins and Barcroft (1) found the renal blood flow, measured by Barcroft and Brodie's method, at least as great in a rabbit acutely poisoned by uranium acetat