STORAGE OF CAROTENOIDS AND OF VITAMINS A 511 



animals for liver,^^'^^^ adrenals/^" heart,^°^ pancreas,'"^ nerves,*'''- bone-mar- 

 ,.Q^y^256 ^j^(j placenta.^^^ Maas isolated an unidentified lipochrome in the 

 seminal vesicles. ^"^ /3-Carotene is the preponderant pigment in the cor- 

 pora lutea, in association with traces of xanthophyll,-^ while lutein may be 

 the only carotenoid present in the macular region of the retina. -^■'^- 



Carotenoids accumulate in human fat throughout life. This presum- 

 ably accounts for the fact, observed by Thomson,^" that the adult fat is 

 yellow while that of the infant is Avhite. When fat is mobilized from the 

 fat depots, the carotenoids remain behind. This accounts for the fact that 

 the fat from emaciated humans is yellower than that from well-nourished 

 subjects. Fat from the abdomen and chest is beheved to have a higher 

 carotenoid content than does that from the thighs and arms.^^^ Aschoff^"^ 

 reported that the carotenoid concentration in fat from the adrenal gland is 

 twenty times, and that from atheromas is ten times, as high as that in sub- 

 cutaneous fat. No carotenoids or vitamin A have been reported in hu- 

 man sweat,^"^ in spermatozoa,^"^ or in cerebrospinal fluid. ^''^ Menken^"^ 

 found that the blood serum of human mothers contained six times as much 

 carotene as did that of the infants, indicating that the placenta is imper- 

 meable to carotene. However, carotene may be converted to vitamin A 

 in the placenta to some extent. The amount of vitamin A in the mother's 

 serum was found to be approximately the same as that in the infant's 

 blood. Colostrum contains large amounts of both carotene and vitamin 

 A.^^ It is a matter of dispute whether or not there are carotenoids in 

 human bile; von Drigalski^"^ stated that they were absent. Willstaedt and 

 Lindquist^^ believe that they have isolated two new carotenoids from liver 

 extract. 



The aA'erage Adtamin A content was calculated by Williams^*^ to be 5,500 

 and 4,680 I.U./kg. of carcass in the case of two men; 69 and 85%, respec- 

 tively, of the total was in the liver. He lists the following values (in 

 I.U./g.) for several human tissues: liver, 156; adrenal, 6.0; kidney, 2.7; 

 heart, 1.4; skin, 1.3; stomach, 1.3; ileum, 1.3; lung, 1.2; spleen, 1.0; 

 colon, 0.8; skeletal muscle, 0.5; and brain, 0.5. The concentration of 

 vitamin A in the liver of normal humans has been reported as 123 I.U./g. 



=33 R. Kuhn and H. Broekmann, Z. physiol. Chem., 206, 41-64 (1932). 



^ G. M. Findlay, J. Pathol. BacierioL, 23, 482-489 (1920). 



601 D. H. Dolley and F. V. Guthrie, /. Med. Research, 42, 289-301 (1921). 



M2 D. H. Dolley and F. V. Guthrie, J. Med. Research, 40, 295-309 (1919). 



^^ F. Maas, Arch. Mikr. Anat., 34, 452-510 (1889). 



«>4 L. Aschoff, Verhandl. deul. pathol. Gss., 27, 145-152 (1934). 



^^ W. von Drigalski, Z. Vitaminforsch., 3, 37-74 (1934"). 



«•« J. G. Menken, Maandschr. Kindergeneesk., 4, 22-35 (1934). 



