Effect of endotoxin on renal function in the dog

Abstract

Studies were made on isolated and intact dog kidneys provided with a controlled renal arterial perfusion pressure. Renal function tests were performed for a period of 1–2 hours. Creatinine and PAH extraction ratios, clearance rates and TmPAH values were calculated. A procedure was devised for the calculation of renal clearances from simultaneously occurring values which obviated errors due to urinary dead space and permitted the measurement of rapid changes in extraction rates. Renal blood flows and urine flows were measured. After administration of endotoxin PAH extraction ratios and extraction rates declined. TmPAH values temporarily fell but within an hour returned to pre-endotoxin levels. Creatinine extraction ratios and rates and urine flow showed irregular changes after endotoxin. Renal hyperemia was observed if the arterial pressure was maintained and especially when smaller injections of endotoxin were administered. It is concluded that the effect of endotoxin on the kidney is primarily a vascular one. There is no evidence for the poisoning of renal tubule cells, and renal vascular occlusion is not observed.