Korean Journal of Nephrology 1995;14(1):7-18.

(Alterations in Tubular Function during Early Phase of Nonoliguric Ischemic Acute Renal Failure in Rabbit)

Yong Keun Kim , Jae Suk Woo, Young Hee Kim , Jin Sup Jung , Sang Ho Lee

Abstract

This study was undertaken to characterize changes in renal tubular function in rabbits with nonoliguric acute renal failure(ARF). Unilateral ischemia was induced by clamping the left renal artery. Alterations in renal function were studied during the early phase(0 3hr) of recovery from 30 or 60 min of ischemia. The right kidney served as a paired control. Ischemia for 30 min caused a marked polyuria which was accompanied by an increase in excretion of Na', K+ and Cl . A marked reduction in reabsorption of glucose and phosphate was also observed. When ischemia was extended to 60 min, these effects were more pronounced. Glomerular filtration rate(GFR) and PAH clearance(Cpgg) were not reduced by 30 min of ischemia, but significantly attenuated by 60 min of ischemia. These results indicate that ischemia induces defects in tubular function before an impairment in GFR or renal blood flow develops. Free water reabsorption was markedly reduced in postischemic kidneys. The slice uptake of PAH was significantly stimulated rather than decreased by 30 or 60 min of in vivo ischemia, which returned to the control values following 30 min of reflow. Tissue oxygen consumption was not impaired even when ischemia was extended to 60 min. These results indicate that a marked defect in proximal tubular reabsorptive function and an impairment in urine concentrating ability are the early events in nonoliguric acute renal failure.