250 V. OXIDATION AND METABOLISM OF PHOSPHOLIPIDS 



stance is effective in the chemotherapy of wounds. This action can be re- 

 versed by certain phosphoHpids. For example, soya lecithin protected 

 Staphylococcus aureus against the inhibitory effect of propamidine. 



(2) The Effect of Choline Deficiency 



In the absence of sufficient choline in the diet, the oxidative metabolism 

 is impaired. According to Abdon and Borglin,^^ the oxygen consumption 

 of the muscle tissue of choline-deficient animals is decreased to two-thirds 

 of its normal value. When choline is added in vitro no improvement is 

 noted, but when it is injected in vivo it is able to correct the impaired func- 

 tion. It is believed that choline or its methyl groups are used in the forma- 

 tion of an unknown coenzyme. According to Artom,^® choline also plays 

 a role in the oxidation of the long-chain fatty acids. When palmitate-1- 

 C'^ was fed to choline-deficient rats, the rate of oxidation was lower than 

 was the case w^hen choline was injected before the animals were sacrificed. 

 This suggests that the choline accelerates the oxidation of long-chain fatty 

 acids as well as that of octanoic acid. It is also possible that the lipotropic 

 action of choline may be due at least in part to the increased catabolism of 

 fatty acids in the liver. Handler and Bernheim^'^ demonstrated that, when 

 choline was absent from the diet of young rats for only one week, a sys- 

 tematic hypertension developed. ^^ On the other hand, the hypertension 

 of partially nephrectomized rats disappeared when they were fed a choline- 

 deficient diet, while it was promptly restored by the administration of 

 ACTH.^^ Baxter and CampbelP^ demonstrated that the renal lesions 

 and the mortality, in the case of animals given a purified diet deficient in 

 choline, could be largely prevented by supplementing the diet with rather 

 high levels of crystalline aureomycin, this also appeared to reduce the 

 extent of the fatty infiltration of the liver. These effects produced by 

 aureomycin were apparently not due to changes in food consumption, and 

 did not appear to involve the endocrine systems. Hartcroft et aZ."* 

 reported that lesions occurred in the aortas, the carotid and the coronary 

 arteries of young rats which had been maintained on low-choline diets 

 for periods up to 216 days. These initial lesions, as identified microscop- 

 ically, involved the endothelial cells of the intima. In later stages a 



35 N. O. Abdon and N. E. Borglin, Nature, 158, 793-794 (1946). 



9« C. Artom, XIX Intern. Physiol. Congr., Montreal, Aug.-Sept., 1953, Abst., 176-177. 



" P. Handler and F. Bernheim, Am. J. Physiol., 162, 189-192 (1950). 



98 P. Handler and F. Bernheim, Am. J. Physiol, 162, 375-378 (1950). 



99 J. H. Baxter and H. Campbell, Proc. Soc. Exptl. Biol. Med., 80, 415-419 (1952). 

 loo W. S. Hartcroft, J. H. Ridout, E. A. Sellers, and C. H. Best, Proc. Soc. Exptl. Biol. 



Med., 81, 384-393 (1952). 



