FATS AS ESSENTIAL DIETARY COMPONENTS 897 



to the amount of lard added. When 50 parts of casein and 10 parts of 

 lard were fed, the protective effect was additive. The number of cavities 

 observ^ed was comparable to that observed when the ration contained 20 

 parts of lard. Aaes-Jorgensen-" pointed out that kidneys from rats reared 

 on a fat-free ration revealed necrosis, apical disintegration, and calcifica- 

 tion in the papilla, and a rather high number of calcuU on the corticomed- 

 ullarj^ border. Although similar changes were observed in the kidneys 

 of rats fed diets containing various hydrogenated fats, the calculi were 

 less numerous. 



Among the harmful effects of fat is the hemolytic anemia caused by 

 fat and choline. Thus, when fats are fed to dogs, an increase in the fra- 

 gility of the red blood cells is noted. The hemolytic agents in fat are 

 presumably the fatty acids and soaps which have escaped resynthesis 

 during absorption.-®* When choline is administered to dogs, in addition 

 to a high-fat diet, the rapid development of an acute hemolj-tic anemia is 

 noted. 2®^ Davis-™'-''^ concludes that the choline aids in the production of 

 hemolytic and hj^perchromic anemia, not by virtue of a lipotropic action, 

 but rather because of its vasodilator or pharmacologic action. However, 

 Clarkson and Best^^- were unable to confirm the general conclusions of 

 Davis in regard to the production of various anemias ;'-^°-^^ they did not 

 observe any trace of macrocytic anemia in dogs foUo^nng the addition 

 of choline or choline plus fat to the stock diet. 



Silberberg and Silberberg-'^ called attention to the fact that male mice 

 fed a diet containing 29% of fat exhibited an increased incidence of osteo- 

 athritis, and an accelerated onset as compared with controls fed 5% of 

 fat. Apparently overweight was not a significant factor in the occurrence 

 of this degenerative joint disease. According to Perdue and Phillips,^^* 

 a diet containing 0.03% potassium and 20% of corn oil increased the in- 

 cidence and extent of mild myocardial necrosis, and of the fibrosis and 

 dilation of the renal tubules typical of potassium deficiencj^ to a greater 

 extent than did an isocaloric 5% corn oil diet containing the same amount 

 of potassium, when the two diets were pair-fed. No statistically signifi- 



-^^ E. Aaes-Jorgensen, XlXth Intern. Physiol. Congress, Montreal, Aug.-Sept., 1953, 

 Ahst., p. 146. 



268 J. Longini and V. Johnson, Am. J. Physiol, UO, 349-353 (1943). 



2«3 J. E. Davis and J. B. Gross, Am. J. Physiol., lU, 444-446 (1945). 



2TO J. E. Davis, Science, 105, 43-44 (1947). 



2" J. E. Davis, Am. J. Physiol., 147, 404-411 (1946). 



2" M. F. Clarkson and C. H. Best, Science, 105, 622-623 (1947). 



"3 M. Silberberg and R. Silberberg, Arch. Pathol., 50, 828-846 (1950). 



"^ H. S. Perdue and P. H. PhiUips, Proc. Soc. Exptl. Biol. Med., 81, 405-407 (1952). 



