Prolonged renal survival and stunting, with protein-deficient diets in experimental uremia. Reversal of these effects by addition of essential amino acids.

The aim of dietary therapy of chronic renal failure is to reduce uremic symptoms while avoiding malnutrition. The possible toxic effects of the diet on the kidney are rarely taken into consideration. The present experiment compared the long-term effects of three low-protein diets in nephrectomized rats (UI, UII, UIII) and in controls: diet I containing 7.5% protein, diet II containing 7.5% protein + 1% EEAs, and diet III containing 14% protein. Nephrectomized rats gained less weight than corresponding controls. UI rats had a decrease in the rate of length gain as opposed to groups UII and UIII. UI, however, maintained a relatively constant GFR, whereas groups UII and UIII had severe reductions in renal function. There were no significant differences between either UII or UIII rats in terms of growth and survival, despite lower consumption not only of proteins but also of all nutrients in the former group measured in a previous study. Thus semisynthetic diet appeared of little benefit. A diet consistent with both normal growth and preservation of renal function remains to be defined.