IX. PHARMACOLOGY 315 



fatty acid deficiency in mice,^" preventable or curable by lard, as in rats. 

 A deficiency may also be produced in the mature as well as the young rat, 

 and ethyl linoleate rapidly relieves the symptoms; recovery also follows a 

 sufficiently prolonged maintenance on a fat-free diet, suggestmg that syn- 

 thesis of essential fatty acids can occur under these circumstances.^^ On the 

 other hand, no synthesis of linoleic or linolenic acids is detected in rats given 

 D2O, as reflected by incorporation of deuterium into the fatty acid molecule, 

 although deuterium is found in palmitic, stearic, and even oleic acids of rats 

 so treated.^-' ^^ As mentioned above, plants^^ and some insects^^ can syn- 

 thesize linoleic acid. Among the unsaturated fatty acids of hair of human 

 adults, the essential fatty acids may have a bactericidal role akin to the 

 fungicidal action postulated for the odd-number C7-13 acids present, in 

 conferring resistance to ringworm in the adult. ^^ 



C. VITAMIN INTERRELATIONSHIPS 



Supplementation of the diet of rats fed carotene with the unsaturated 

 fatty acids of butter results in accumulation of twice as much vitamin A 

 in the liver as when saturated fatty acids are given. *^ Other work^^ indicates 

 that the utilization of carotene from oils depends on the vitamin E rather 

 than linoleic acid content. Gossypol has been shown to increase the effects 

 of suboptimal supplements of vitamin A and lard or methyl linoleate in 

 diets deficient in both vitamin A and the essential fatty acids, acting as an 

 antoxidant.^^ An antagonism between carotene and linoleic or linolenic 

 esters in rats deficient in vitamin A is said to be prevented by a-tocopherol, 

 probably by the same mechanism. ^'^ Among the vitamin B complex, the 

 essential fatty acids antagonize the lipotropic effect of inositol in rats but 

 have no effect on the action of choline. ^^ In rat dermatitis, ethyl linoleate 

 has a curative action whereas pyridoxine at best only alleviates, but pyri- 

 doxine will potentiate subcurative doses of ethyl linoleate.^" The anti- 



5" E. A. White, J. R. Foy, and L. R. Cere^edo, Proc. Soc. Exptl. Biol. Med. 54, 301 

 (1943). 



5' V. H. Barki, H. Nath, E. B. Hart, and C. A. Elvehjem, Proc. Soc. Exptl. Biol. Med. 

 66, 474 (1947). 



« K. Bernhard, H. Steinhauser, and F. Bullet, Helv. Chim. Acta 25, 1913 (1942). 



"F. Bullet and K. Bernhard, Helv. Physiol, et Pharmacol. Acta 1, C39 (1943). 



" A. W. Weitkamp, A. M. Smiljanic, and S. Rothman, /. Am. Chem. Soc. 69, 1936 

 (1947). 



" E. F. Brown and W. R. Bloor, /. Nutrition 29, 349 (1945). 



»«S. D. Rao, Nature 156, 234, 449 (1945). 



" E. L. Hove, /. Biol. Chem. 156, 633 (1944). 



58 W. C. Sherman, Proc. Soc. Exptl. Biol. Med. 47, 109 (1941). 



" J. M. R. Beveridge and C. C. Lucas, ./. Biol. Chem. 157, 311 (1945). 



^^ F. W. Quackenhush, H. Steeny)ock, F. A. Kummerow, and B. R. Platz, J. Nutri- 

 tion 24, 225 (1942). 



