Glycerol-induced acute renal failure attenuates subsequent HgCl2-associated nephrotoxicity:: Correlation of renal function and morphology

Glycerol induced acute renal failure (ARF) is known to attenuate subsequent mercuric chloride nephrotoxicity. This protection was evaluated in rats. Glycerol induced varying degrees of renal insufficiency. After 14 days, when serum creatinine (S-Cr) creatinine clearance (C-Cr) and fractional excretion of sodium (FENa) had returned to baseline, injection of mercuric chloride caused significantly milder renal insufficiency in recovered rats than in controls (Sc, 356 +/- 46 vs. 475 +/- 19 mu mol/L; C-Cr 0.12 +/- 0.02 vs. 0.02 +/- 0.02 mL/min, p < .05, and mortality 0 vs. 45%, respectively, p < .01). A striking finding was that the degree of renal insufficiency induced by mercuric chloride correlated inversely with the degree of renal insufficiency previously induced by glycerol (r = -0.496, p < .05 for S-Cr and C-Cr), but there was no correlation with other measures of previous renal function such as urine volume, sodium excretion or FENa. Glycerol induced ARF also attenuated the renal toxicity of mercuric chloride injected 4 days after glycerol, before full recovery of renal function. The decrements in renal function after the two insults were also inversely related (r = -0.76, p < .01). A third renal insult with a second mercuric chloride injection after three weeks was still attenuated.