[Renal perfusion during experimental hyper-acute rejection. 133-xenon perfusion compared with microscopy and...

Twenty-two cat kidneys and 11 pig kidneys were incorporated into canine circulatory systems. The delayed hyper-acute and hyper-acute rejections produced by these models were studied with respect to blood flow and blood distribution with an intra-arterial 133-xenon wash-out technique at intervals of 7-30 minutes until the death of the kidney at 40 minutes to twelve hours. In addition, magnification angiograms and serial cortical biopsies were obtained for continuous histological study of the rejection phenomenon. At the beginning of the rejection process, there is a reduction in blood-flow through the cortex. During delayed hyper-acute rejection, cortical flow could no longer be demonstrated 180 minutes after the period of flow maximum. After A.L.G. treatment of dogs, rejection could be delayed for ten to twelve hours. Magnification angiograms showed characteristic changes consisting of irregular segmental and interlobar arteries, occlusion of small cortical vessels and focal contrast accumulation in the renal cortex. The changes in blood-flow and blood distribution measured with 133-xenon and the vascular findings on the angiogram could be correlated with the microscopic findings. Serial estimations of blood flow and blood distribution with the xenon blood wash-out technique permit differentiation between shock kidney and rejection following renal transplantation.