718 XI. VITAMINS E (tocopherols) 



the placenta and fetal death. Ingelman-Sundberg-'^ suggested that it 

 can be explained as an abortion due to the premature separation of the 

 placenta. 



When vitamin E is lacking, fetal death occurs in the incubating hen's egg 

 on about the fourth day. Adamstone^^-^" considers this to be the result 

 of disintegration of the blood vessels of the l)lastodenn, and hemorrhage 

 into the coelom and exocoelom, followed by cellular proliferations in the 

 blastoderm, which cause an interruption in \'ite]line circulation. If this 

 critical period does not develop in the embryo, a spontaneous rupture of 

 the vascular vessels at different sites within the embryo may take place 

 later. 



d. The Role of Vitamin E in Relation to Skeletal Muscle. The role of 

 vitamin E in muscle metabolism is the most widely recognized of any of its 

 functions. ^^2 '2'* The effects of an avitaminosis E on muscle metabolism 

 and morphology have been reported in nineteen of the species investi- 

 gated,^^ and no instances are recorded in which the requirement is not evi- 

 dent. Although the histopathologic patterns of skeletal muscle, subject 

 to nutritional muscular dystrophy due to lack of sufficient vitamin E, 

 vary from species to species, and, in fact, even in the same species at differ- 

 ent ages, two types of abnormality are quite consistent in the various ani- 

 mals, namely an acute type of reaction in young animals (as exemplified by 

 late-lactation paralysis) and a chronic type in older animals (as seen in 

 nutritional muscular dystrophy). These histologic deviations from the 

 normal muscle structure undoubtedly reflect a vitally important function 

 of tocopherol, but the nature of this metabolic effect is not understood. 

 It occurs in the young weanKng rat as "late-lactation" paralysis due to the 

 inadequate storage of a-tocopherol. This results from the fact that the 

 combined placental and mammary transfer of \atamin E is so small that it 

 is barely able to satisfy the ordinary needs of the growing mammal. De- 

 ficiency is likely to occur during late lactation, both because of the rapid 

 growth in this period, and because of the decreasing concentration of 

 vitamin E present in the milk as lactation progresses. 



(a) Late-Lactation Paralysis. Evans and Burr^^ first called attention 

 to the generalized paralysis in suckling rats, usuall}^ occurring between the 

 eighteenth and the twenty-fifth days of life. The onset of the paralysis is 

 usually quite sudden. This involves a flexor spasm of the forepaws, 



236 A. Ingelman-Sundberg, Acta Endocrinol, 2, 335-346 (1949). 



237 F. B. Adamstone, Arch. Pathol., 31, 622-626 (1941). 



238 w. T. West and K. E. Mason, Proc. Third Med. Conf. Muscular Dystrophy, Muse. 

 Dystr. Assoc, New York, 1954, pp. 223-239. 



