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Scientific Proceedings (132) 



226 (2186) 



Kidney hypertrophy produced by diets unusually rich in protein. 



By THOMAS B. OSBORNE, LAFAYETTE B. MENDEL, EDWARDS A. 

 PARK and D. DARROW. 



[From the Laboratory of the Connecticut Agricultural Experiment 

 Station, the Sheffield Laboratory of Physiological Chemistry, 

 Yale University, and the Department of Pediatrics, 

 Yale University, New Haven, Conn.] 



In preliminary reports 1 Osborne and Mendel demonstrated 

 that rats can grow to considerable size on diets consisting of 

 nine-tenths or more of protein, provided that they receive a 

 suitable supply of vitamins A and B as well as of inorganic salts. 

 Both casein and washed meat were used as the sources of the 

 protein. Similar tests have since been made with rations con- 

 taining about 75 per cent, of protein in the diet. It seemed un- 

 likely that rations on which young rats grew from 60 to 260 

 grams could be extremely harmful to the organism. However 

 Squier and Newburgh 2 have concluded, in harmony with a wide- 

 spread popular belief, that "a high protein diet in man is a renal 

 irritant" ; and Newburgh and Clarkson 3 have described the pro- 

 duction of arteriosclerosis in rabbits on "diets containing 27 

 and 36 per cent, of protein derived chiefly from beef." For 

 this reason it seems worth while to give a preliminary account 

 of our observations on some of the organs of rats growing 

 on our diets very high in protein. 



The only striking change was found in the kidneys, which in 

 the animals on the high protein diets were greatly hypertrophied. 

 The average weight of the kidneys was almost twice that of the 

 kidneys of control animals and their size about one-third greater. 

 Microscopic examination showed no changes of an inflammatory 

 or degenerative nature. The exact histological condition of the 

 kidneys and of the other organs will be reported in full in a 



1 Osborne, T. B., and Mendel, L. B., Proc. Soc. Exp. Biol, and Med., 1921, 

 xviii, 167; Proc. Nat. Acad. Sc., 1921, vii, 157. 



2 Squier, T. L., and Newburgh, L. H., Arch. Int. Med., 1921, xxviii, 1. 



8 Newburgh, L. H., and Clarkson, S., Jour. Am. Med. Assn., 1922, lxxix, 

 1106. 



