MISCELLANEOUS WATER-SOLUBLE GROWTH FACTORS 



References to Section i 



1. K. O'S. Elsom, F. H. Lewy and G. W. Heublein, Amer. J. Med. Sci., 



1940, 200, 757. 



2. A. Keys, A. F. Henschel, H. L. Taylor, O. Mickelsen and J. Brozek, 



Amer. J. Physiol., 1945, 144, 5. 



3. A. G. Clarke and F. Prescott, Brit. Med. J., 1943, 2, 503. 



4. E. C. Miller and C. A. Baumann, /. Nutrition, 1944, 27, 319. 



5. A. F. Morgan, Science, 1941, 93, 261. 



6. G. C. Supplee, R. C. Bender and Z. M. Hanford, /. Amer. Pharm. 



Assoc, 1942, 31, 194. 



7. K. Unna and J. D. Clark, Amer. J. Med. Sci., 1942, 204, 364. 



2. INADEQUACY OF KNOWN VITAMINS FOR ANI2V1ALS 



Although aneurine, riboflavine and nicotinic acid are undoubtedly 

 the most important of the B vitamins for both animals and humans, 

 there is abundant evidence from animal experiments that other water- 

 soluble nutritional factors exist in addition to the recognised members 

 of the vitamin B complex, vitamin C and vitamin P. These are not 

 of major importance in human or animal nutrition and their absence 

 generally results in comparatively trivial disturbances in the well- 

 being of experimental animals, although a prolonged deficiency may 

 sometimes result in death. 



Mice and Rats 



E. R. Norris and J. Hauschildt ^ claimed that another factor in 

 addition to aneurine, nicotinic acid, riboflavine, pyridoxine and 

 " filtrate factor " was necessary to prevent skin lesions and loss of 

 hair in mice fed a purified diet. Similarly, K. Schwartz ^ claimed 

 that a new factor was necessary to increase the weight of pantothenic 

 acid-deficient rats beyond the limit reached by administration of 

 pantothenic acid alone ; the factor was termed " factor 125 " because 

 with pantothenic acid alone the growth rate began to decrease when 

 the rats weighed 125 g. 



Dogs 



Dogs manifested symptoms of deficiency when fed a purified diet 

 supplemented by a mixture of synthetic B vitamins. Schaefer et al.^ 

 found that a factor in liver restored the growth and prevented anorexia 

 in dogs maintained on a casein-sucrose diet supplemented by aneurine, 

 riboflavine, nicotinic acid, pyridoxine, pantothenic acid and choline, 

 whilst Smith et al.^ found that a factor in yeast supplemented pyrid- 

 oxine in improving the blood picture and general health of dogs 



608 



