AJP - Renal Physiology, Vol 250, Issue 2 315-F321, Copyright © 1986 by American Physiological Society
Role of volume depletion in the glycerol model of acute renal failure
H. M. Cushner, J. L. Barnes, J. H. Stein and H. J. Reineck
Previous studies have demonstrated significant volume depletion early in
the course of glycerol-induced acute renal failure. In addition, it has
been shown that acute volume expansion within 6 h of glycerol
administration reverses the fall in inulin clearance but volume expansion
12-24 h after glycerol fails to restore that parameter to normal. The
current studies were performed to determine whether chronic volume
expansion would prevent the fall in inulin clearance normally observed
18-20 h after the insult. Inulin clearance was therefore compared 18-20 h
after glycerol in hydropenic rats and in rats undergoing chronic volume
expansion by the constant infusion of Ringer solution at a rate of 5 ml/h
initiated at the time of the glycerol injection. Inulin clearance was well
maintained in the latter group, averaging 1.77 compared with 0.22 ml/min in
the hydropenic group. Renal histology revealed no difference in the degree
of tubular necrosis between groups but did show a marked decrease in cast
formation in the animals undergoing chronic volume expansion. To determine
the possible significance of these casts, micropuncture studies were
carried out to measure proximal tubular pressures. Under hydropenic
conditions these pressures were not different control animals and rats
receiving glycerol when studied 18-20 h after glycerol. Following acute
volume expansion, however, glycerol-treated rats demonstrated significantly
higher pressures than control rats. On the other hand, proximal tubular
pressures were comparable in glycerol-treated and control animals receiving
the chronic volume expansion.(ABSTRACT TRUNCATED AT 250 WORDS)
