Dietary Protein in Hemorrhagic Bright's Disease

The question of the possibility of injury to the kidneys by the proteins of the diet has received the attention of a number of investigators. Recently Newburgh and coworkers have published some observations which throw new light on the problem. In 1919 Newburgh (14) reported a series of experiments in which renal injury was observed in rabbits to which high protein diets were given. In 1928 a further report (15) was made of experiments in which white rats were given 75 per cent of their diet in the form of proteins, either as liver, or as beef muscle, or as casein. Renal injury was noted in all groups after varying lengths of time. In the group receiving liver, the kidneys at autopsy were enlarged, granular and characterized by both glomerular and tubular lesions and fibrosis. These changes were well marked at the end of "less than a year" of the liver diet. In the case of casein the renal injury was least marked, being confined to the tubules, and required the longest time for its production, while the lesions occurring in the group receiving beef muscle were intermediate between the two extremes both in degree and in the rapidity of their production. In a more recent report Newburgh (16) expressed the belief that the difference in results obtained in previous work was due to the nephrotoxic effects of products of nuclear material and not to the proteins per se, since feeding of sodium nucleate produced hematuria. He was able to produce kidney injury with less than 75 per cent of liver in 80 per cent of the animals.