B VITAMIN DEFICIENCY STATES 425 



Studies on adrenalectomized rats have done much to elucidate this 

 relationship. 172 Adrenalectomy has been shown to accelerate the growth 

 of new hair in both normal and pantothenic acid-deficient rats, and in 

 the avitaminotic animals it restores the color of the hair and the skin. 

 Finally, it accelerates recovery when pantothenic acid is administered. 

 A bluish pigmentation of the skin develops in the adrenalectomized rat; 

 it reaches a maximum after about two weeks and then fades. This color- 

 ation is due to widespread accumulation of melanin in hair bulbs and 

 follicles, and hair graying in pantothenate deficiency results from atrophy 

 of the hair apparatus and a cessation of melanin deposition. The skin 

 pigmentation occurs in all the operated animals, but lasts for a shorter 

 time in the deficient animals. Finally, in adrenalectomized deficient rats, 

 desoxycorticosterone acetate prevents the effects of the operation on hair 

 growth and color. It is thus clear that any adrenal insufficiency in panto- 

 thenic acid deficiency is not primarily concerned with the absence of 

 desoxycorticosterone, since the latter substance is necessary to produce 

 the gray hair symptom. 173 This vitamin-hormone interrelationship is one 

 that merits further study in the immediate future. 



The bronzing of the skin in Addison's disease is in some ways sug- 

 gestive of the fundamental role of the adrenals in pigmentation. The 

 structural relationships between the medullary adrenaline and the known 

 precursors of melanin, and between adrenaline and tyramine, which is an 

 endocrine substance controlling pigmentation in certain molluscs, further 

 suggest that both portions of the suprarenal gland function in pigmenta- 

 tion. The avitaminosis-induced hair graying and porphyrin deposition 

 might conceivably both be linked to the adrenal atrophy. It is well known 

 that the adrenals are intimately associated with the mineral balance, 

 and a number of interesting factors in apantothenosis are undoubtedly 

 associated with this fact. Low salt diets seem to favor the hair-graying 

 process, and deficient animals have an increased salt appetite. The in- 

 volvement of the adrenals in water balance recalls the blood-soaked 

 whiskers appearance of rats due to water deprivation — a condition char- 

 acteristic of this avitaminosis but in this case not cured by pantothenic 

 acid. 



While nervous lesions are common to most B vitamin deficiencies, the 

 role of pantothenic acid in acetylcholine synthesis would cause one to 

 predict particularly severe symptoms in this case. If pantothenate func- 

 tions in the multiple acetate condensation that occurs in fat synthesis 

 and oxidation, then the fatty liver symptom found in the avitaminosis 

 might be explained. 



Finally, other symptoms of pantothenate deficiency are doubtless 

 associated with the role of pantothenate in carbohydrate metabolism. 



