Effect of ascorbic acid and ferrous iron on p-aminohippurate accumulation by rat kidney cortical slices

The effect of ascorbic acid and Fe2+ on p-aminohippurate accumulation by rat kidney slices was examined. Ascorbic acid and Fe2+ promoted lipid peroxidation of rat renal cortical slices was found to be dose related. Moreover, ascorbic acid (1.0 mM) and Fe2+ (0.4 mM) increased tissue water and decreased the accumulation of p-aminohippurate. The addition of N,N'-diphenyl-p-phenylenediamine (antioxidant) at the concentration of 1 x 10(-6) M recovered the accumulation of p-aminohippurate by about 43%. The apparent Km of p-aminohippurate uptake was increased by ascorbic acid and Fe2+ with no change in the apparent V. These data suggest that ascorbic acid and Fe2+ can cause a significant alteration in p-aminohippurate and water transport of renal cortical slices and that these effects may be, at least, partly due to the lipid peroxidative action of ascorbic acid and Fe2+.