BIOTIN 



therefore, hydrolysis with dilute acid or with trypsin should be used 

 to ensure liberation of combined biotin.'^' ® 



Royal jelly was an exceptionally rich source of biotin, as it was of 

 pantothenic acid, containing 4-1 /xg, per g. ; pollen and honey con- 

 tained 0-25 and o-ooo66 fig. per g. respectively.^ 



Biotin was present in soil and natural manures, and the amount 

 in pasture land was increased by farmyard manure. The soil concen- 

 tration varied with the depth, but in lake deposits biotin was detected 

 to a depth of 9 metres.^® 



References to Section 8 



1. P. Gyorgy, /. Biol. Chem., 1939, 131, 733. 



2. J. M. Lawrence, B. L. Herrington and L, A. Maynard, /. Nutrition, 



1946, 32, 73. 



3. F. Kogl and A. J. Haagen-Smit, Z. physiol. Chem., 1936, 243, 209. 



4. F. Kogl and W. von Hasselt, ihid., 189. 



5. B. S. Schweigert, E. Nielsen, J. M. Mclntire and C. A. Elvehjem, 



/. Nutrition, 1943, 26, 65. 



6. R. A. Sullivan, E. Nielsen and J. Jarmol, ihid., 1943, 25, 463. 



7. R. C. Thompson, R. E. Eakin and R. J. Williams, Science, 1941, 



94. 589. 



8. J. O. Lampen, G. P. Bahler and W. H. Peterson, /. Nutrition, 



1943. 23, II ; J. P. Bowden and W. H. Peterson, /. Biol. Chem., 

 1949, 178, 533. 



9. G. Kitzes, H. A. Schuette and C. A. Elvehjem, /. Nutrition, 1943, 



26, 241. 

 10. M. A. Roulet, Experientia, 1948, 4, 149. 



9. EFFECT OF BIOTIN DEFICIENCY IN ANIMALS 



Rats and Mice 



As already mentioned above, biotin deficiency produced by feeding 

 raw egg white to rats is characterised by an eczema-like dermatitis, 

 paralysis or spasticity of the hind legs and the so-called " spectacle- 

 eye " condition caused by loss of hair around the eyes. Although 

 nutritional achromotrichia was relieved by pantothenic acid,^ the 

 dermatitis and other symptoms did not respond to pantothenic acid, 

 or to riboflavine, pyridoxine or inositol, but were cured by adminis- 

 tration of 2 /Ltg. of biotin per day ; ^ the growth rate was also increased 

 thereby. When biotin-deficient rats were treated with biotin (0-5 to 

 i-o /xg. per day), the animals recovered, but their coats became grey 

 in a different pattern from that assumed by pantothenic acid-deficient 

 rats.^ Cooked white of egg did not produce biotin deficiency, the 

 responsible factor being heat-labile (see page 427). 



424 



