Effects of dietary protein on renal ischemia induced tubular necrosis.

Previously we have shown that the amount of protein in a dietary regimen prior to the induction of renal ischemia will significantly affect the degree of postischemic acute renal failure (Andrews PM, Bates SB: Kidney Int 30:299-303, 1986). The present investigation was undertaken to determine what effect dietary protein regimen has on the histopathology of renal ischemia. Rats were pair-fed for 2 weeks on either 0% or 5% (restricted), 20% (normal), or 60% (high) purified protein isocaloric diets. Ischemia was induced by 45 min of renal pedicle clamping. Light and electron microscopic evaluation of kidney morphology immediately following renal ischemia (prior to blood reflow) revealed that the extent of morphological damage to cells lining proximal convoluted tubules and the thick ascending segments of Henle's loop increased with increasing concentration of dietary protein. However, all dietary protein groups also exhibited heterogeneity in the extent of damage to different nephrons within the same kidney.