NA-23 NMR DETECTS PROTECTION BY GLYCINE AND ALANINE AGAINST HYPOXIC INJURY IN THE ISOLATED-PERFUSED RAT-KIDNEY

Protection against hypoxic injury by supraphysiological glycine and al anine concentrations was investigated in the isolated perfused rat kid ney (IPRK). Na-23 NMR detects consistent increases in total renal Na i n IPRK during hypoxic perfusion. Increasing the concentration of glyci ne and alanine to 5 mM each produced a 34% (p<0.001) reduction in the increase in total renal Na following 30 minutes of hypoxia compared to a matched control group supplemented with 5 mM each of serine and glu tamine. There was also a trend (p=0.067) to improvement in the fractio nal excretion of sodium (FE(Na)) in the glycine plus alanine treated g roup. Hypoxic alterations of other physiological parameters were not p revented by supraphysiological glycine plus alanine. This suggests tha t monitoring total renal Na is a more sensitive method of defining ren al injury and protection than monitoring changes in FE(Na), fractional excretion of potassium (FE(K)) and inulin clearance. (C) 1994 Academi c Press, Inc.