OCCURRENCE OF THE TOCOPHEROLS 803 



The body of the newborn rat contains only a small amount of vitamin E, 

 in spite of a large intake of tocopherol by the mother. Although the uterus 

 and placenta are able to take up a considerable amount of vitamin E, ap- 

 parently the latter cannot be transmitted to the fetus. The deficiency in 

 vitamin E is rapidly corrected in the offspring after birth; this is probably 

 due to the high content in the milk, although the vitamin E content of rat 

 colostrum is not known. The exceedingly high tocopherol value of mam- 

 mary tissue is of considerable interest in this connection. 



Preferential absorption of rf-a-tocopherol as compared with that of d-y- 

 tocopherol has been demonstrated by Quaife et al.^^ in the human subject. 

 After 500-mg. doses of a-tocopherol, the serum tocopherol reached a 

 maximum level of approximately 1.75 mg. per 100 milliliters of serum after 

 4 hours; when 7-tocopherol was given, the maximum was reached after 

 about the same interval, and amounted to only 1.35 mg. per 100 milliliters 

 of serum.®* The normal value for tocopherol in man is 1.00 milligram per 

 cent''^; 75% is a-, and the balance non-a-tocopherol. 



The relatively low content of tocopherol in the body fat, muscles, urine, 

 feces, and blood of rats indicates that the absorption must be very in- 

 efficient, or that the substance is readily susceptible to destruction in the 

 gastrointestinal tract, or both. It is also possible that the destruction 

 within the tissues is rapid ; the low content may be the result of inefficient 

 storage. ^^•''^ 



The absorption of the tocopherols requires the intermediation of bile, 

 just as fat and carotene do. Thus, it has been demonstrated that rats" 

 and dogs^^'^* with bile fistulas are unable to absorb vitamin E; Mason ^^ 

 believes that this deficiency is related to the failure of such animals to 

 utilize this fat-soluble component from dietaiy sources. 



The tocopherol content of several animal fats which have been studied is 

 exceedingly low.'^^ The values reported vary between 0.2 and 4.2 mg. per 

 100 grams of fat.'^^ This level is exceedingly low as compared with a figure 

 of 400 mg. per gram of wheat genu oil or 100 mg. per gram of cottonseed oil. 

 Oleo oiF® contains only 2 mg. of the vitamin per 100 grams of fat; accord- 

 ing to Kofler,"" the tocopherol content of beef tallow is only 1 milligram 

 per cent. In the case of butter, a range of 1.7 to 4.2 mg. per 100 grams has 



's M. L. Quaife, N. S. Scrimshaw, and O. H. Lowrv, /. Biol Chem., 180, 1229-1235 

 (1949). 



"6 T. Moore and K. R. Rajagopal, Biochem. J., 34, 335-342 (1940). 



" J. D. Greaves and C. L. A. Schmidt, Proc. Soc. Exptl. Biol. Med., 37, 40-42 (1937). 



"8 K. M. Brinkhous and E. D. Warner, Ayri. J. Path., 17, 81-86 (1941). 



"' H. J. Deuel, Jr., in A. E. Bailev, Cottonseed and Cottonseed Products, Interscience, 

 New York, 1948, p. 772. 



"" M. Kofler, Helv. Chim. Acta, 26, 2166-2176 (1943). 



