PHYSIOLOGIC FUNCTIONS 819 



stated that fat cannot be laid down in the tissues on an EFA-deficient diet. 

 This situation would also result in failure of growth. 



The problem of the mechanism of action of EFA in the animal body is 

 largely unsolved. Greenberg and Ershoff' ^"^ demonstrated an interesting 

 relationship between EFA and the development of the prostate and seminal 

 vesicle. A marked reduction in the weights of both organs occurred in EFA 

 deficienc3^ This could be corrected either by gonadotropin or by the 

 administration of methyl linoleate. 



{2) Xonnal Skin, Development 



The most consistent s^miptom of EFA deficiency throughout the \'arious 

 species of animals is the condition of the skin and hair. In the case of man, 

 absence of EFA is associated ■\^•ith an eczematous condition. The chief 

 symptoms in rats, mice, dogs and calves are scaliness of the tail, and rough- 

 ness of the skin. In the rat, mouse, and dog, another common symptom 

 is scaliness of the paws. 



The skin symptoms resulting from pyridoxine deficiency and from lack 

 of EFA closely resemble each other. Thus, Birch and Gyorgy^^^ reported 

 that dermatitis, produced by a low-pyridoxine diet, could be cured when 

 lard Avas added to the diet. In later work. Birch ^^^ demonstrated that the 

 presence of fat in the diet delayed the onset of skin s>anptoms on a diet low 

 in vitamin Be ; in fact, it was proved that the skin symptoms resulting from 

 pyridoxine deficiency could be prevented by fat feeding even up to the time 

 the animals succumbed from avitaminosis. Quackenbush et al.^^'' noted 

 that, although pyridoxine produced a temporarj^ alleviation, it did not 

 effect a cure. Pantothenic acid was completely without effect in counter- 

 acting the symptoms produced b}^ fat deficiency. 



Linoleic and arachidonic acids are the most eft'ecti\'e of the acids in clear- 

 ing up the skin symptoms resulting from pyridoxine deficiency or from fat 

 deficiency. Quackenbush and co-workers^^^ are of the opinion that lino- 

 leic acid is more effective than linolenic acid as an antidermatitis factor. 

 In Ime with this result, Burr et al.^^ reported that corn oil (which has no 

 linolenic acid) is more potent in preventing the skin disorders of fat-defi- 

 cient animals than is linseed oil (which is relatively rich in linolenic acid at 

 the expense of linoleic acid). In fact, the ability of natural fats to counter- 

 act the skin disorders has been found to be in proportion to the linoleic 



i'«S. M. Greenberg and B, H. Ershoff, Proc. Soc. Exptl. Biol. Med., 78, 552-554 

 (1951). 



"' F. W. Quackenbush, H. Steenbock, F. A. Kiuiimerow, and B. R. Pkitz, /. Nutrition, 

 ^4,225-234(1942). 



