Effect of various protein diets on growth, renal function, and survival of uremic rats

The effects on growth, renal function, and survival of three isocaloric diets of various protein content (14, 27, and 37 g/100 g in diets I, II, and III, respectively) were compared in uremic rats and in controls. Diet I provided the minimal requirements in all amino acids for gorwing rats. In controls fed ad lib, weight and length gain were better with high protein diets, whereas they were inversely related to the diet protein content in uremic rats. The higher the protein intake, the higher the progressive elevation of BUN and serum creatinine and the mortality rate. Because proteins were supplied by fish flour, their increase was associated with increased mineral content, and the conclusions are restricted to the use of natural proteins: a moderately restricted protein diet securing only the minimal requirements had a beneficial effect on growth and survival of rats with reduced kidney mass. Avoiding any excess in proteins from the early stage of renal disease is suggested.