TOrOPHEROLS IN VAT^TOUS METABOLIC PROCESSES 721 



tablished the fact that vitamin E deficiency was the causative agent. Be- 

 cause of the ease with which muscular dystrophy can he induced iu the 

 rahl)it l)y diet and cured by a-tocopherol, much of the experimental work 

 has l)een carried out on this species."" Accordhig to Harris et al.,^^ the 

 type of dystrophy observed in the rabbit is the acute or explosiA^e type, 

 which is exemplified by late-lactation paralj^sis, rather than the chronic 

 type exhibited by the adult rat. However, it is believed that the basic 

 alterations which occur in the muscle fibers are fundamentally similar in 

 both tj^pes. Considerable experimental work on the subject of muscular 

 dystrophy due to vitamin E deficiency has been carried out on the rat. 

 The gross and microscopic details of dystrophy in young adults and in 

 mature animals of this species have been recorded by Ringsted,-''^ by 

 Einarson and Ringsted,-''^ Evans et al.,^'^^ Knowlton and associates, ^'^■* 

 Mackenzie and co-workers,"^ Pappenheimer,^^^ Martin and Moore, ^^'- 

 Monnier,"^'^" and by Mason and Emmel.-"^ The paresis is characterized 

 by a waddling and slightly incoordinated gait.^'^* This is followed by 

 straddling of the hind legs, inability to walk or to stand, hyperflexion of the 

 toes, flabbiness and weakness of the muscles, involving the adductor thigh 

 muscles, dragging of the hind legs, distinct ataxia, pronounced muscle 

 atrophy, and deformation of the feet. The animals are hump-backed, 

 unkempt, and frequently develop skin ulcerations. Once the paresis is 

 well established, vitamin E therapy can only arrest it. The growth and 

 well-being of the rat are improved by a-tocopherol, but the paralysis 

 remains permanent. ^"^-"^'-^^ The result of vitamin E differs from that in 

 the rabbit; in the latter species vitamin therapy results in the disappear- 

 ance of the paralysis. 2^" 



In addition to the rabbit, guhiea pig, and rat, the young mouse is also 

 subject to nutritional muscular dystrophy,^!* as are also the hamster,-^^ 

 the cotton rat,-^^ the dog,^^^ and the monkey."^ 



2™ C. G. Mackenzie, Proc. Soc. Exptl. Biol. Med., 49, 313-317 (1942). 



271 A. Ringsted, Biochem. J., 29, 788-795 (1935). 



272 L. Einarson and A. Ringsted, Effect of Chronic Vitamin E Deficiency on the Nervovs 

 System and the Skeletal Musculature in Adult Rats. Levin and Miinksgaard, Copenhagen, 

 1938. Cited by L. Einarson, Acta Psychiat. Neurol. Scand., Suppl. No. 78, 8-76 (1952). 



273 H. M. Evans, G. A. Emerson, and I. R. Telford, Proc. Soc. Exptl. Biol. Med., 38, 

 625-627(1938). 



27^ G. C. Knowlton, H. M. Hines, and K. M. Brinkhous, Proc. Soc. Exptl. Biol. Med., 

 41, 453-456 (1939); 4^, 804-809 (1939). 



276 C. G. Mackenzie, J. B. Mackenzie, and E. V. McCollum, Proc. S02. Exptl. Biol. 

 Med., 44, 95-98 (1940). 



276 M. Monnier, Compt. rend. soc. phys. et hist. nat. {Geneve), 57, 252-257 (1940). 



277 M. Monnier, Z. Vitaminforsch., 11, 235-258 (1941). 



278 K. E. Mason and I. R. Telford, Arch. Pathol, 48, 363-373 (1947). 



