Na intake, renal renin, and the severity of myohemoglobinuric renal failure in rats

Abstract

We have examined the role of dietary Na and renal cortical renin concentration (RCRC) on the severity of glycerol-induced acute renal failure (ARF) in the rat. Na loading (1% NaCl to drink) and Na deprivation (Na-free diet) of 5-6 wk duration decreased and increased RCRC, respectively, with respect to control. As assessed by blood urea nitrogen measured 48 h after glycerol injection, the severity of ARF was inversely related to RCRC. However, this was not a causal relationship. Either 6- or 48-h access to 1% NaCl did not lower RCRC of previously Na-deprived rats, but did decrease the severity of ARF. Conversely, 6- or 48-h access to tap water did not increase RCRC of previously Na-loaded rats, but did increase severity of ARF. A significant inverse correlation was found between severity of ARF and Na excretion prior to glycerol injection, a finding consistent with the hypothesis that solute diuresis has a protective effect.