Redistribution of intrarenal blood flow in the patients with chronic renal disease.

In order to study the distribution of blood flow in diseased human kidneys, Xe133 washout curves were obtained from 34 patients with chronic renal disease or hypertension. The curves recorded for over 45 min. were resolved into 4 components, while the curves recorded for 30 min. showed 3 components. The values of components I, II and III in the 30 min. record coincided with those of the components I, the average of II and III, and IV in the 45 min. record, respectively. The percentage of the total renal blood flow (flow ratio) distributed to the component I of the 30 min. record was correlated with that due to cortical blood flow as determined by the dye-dilution method. It is suggested that the component I of the Xe133 washout curve from the human kidney represents the cortical blood flow. The results obtained from the Xe133 washout curves recorded for 30 min. were compared with the renal function of the patients. The flow for unit mass of tissue (flow rate) and the flow ratio of the fastest component (component I) were decreased in the azotemics. The flow rate of component I was also decreased in proportion to the reduction of the RBF calculated from CPAH (RBFPAH), GFR from CThio and maximal urinary osmolality, while the flow rate of component II did not change significantly. As the renal function became impaired to the level of RBFPAH less than 500ml./min., GFR 50ml./min. and maximal urinary osmolality 700mOsm, the flow ratio of component I decreased and that of component II increased progressively.