Chapter III 



RIBOFLAVINE 



I. INTRODUCTION 



In the course of an investigation into the nature of pellagra, J. 

 Goldberger and R. D. Lillie ^ produced a deficiency disease in rats, 

 characterised by ophthalmic and bilaterally symmetrical denuded 

 areas. The factor that prevented these lesions was heat-stable, in 

 contrast to vitamin B^, which is heat-labile. It was termed by 

 Goldberger, the P.P. (pellagra-preventive) factor, but was subse- 

 quently designated vitamin Bg in Britain and vitamin G in the 

 U.S.A.2 



The symptoms reported by other workers as characteristic of 

 vitamin Bg deficiency varied considerably, however, and frequently 

 differed markedly from those observed by Goldberger and Lillie. In 

 particular, some workers reported only an absence of growth, whilst 

 others noted the appearance of dermatitis in some of the experimental 

 animals. It was shown by means of improved technique ^ that failure 

 to grow and the onset of dermatitis were due to a deficiency of two 

 different factors, and either symptom could be produced at will by 

 omitting one factor or the other. The second factor was termed 

 vitamin H in the U.S.A. ^ and vitamin Bg in Europe. Unfortunately, 

 however, the term vitamin H has also been used to describe the factor 

 now known as biotin (see page 404). Absence of vitamin Bg was 

 responsible for the failure of the experimental animals to grow, whilst 

 absence of vitamin Bg was responsible for the dermatitis — the so-called 

 rat " pellagra ". 



Thus, initially, the term vitamin Bg was intended to describe the 

 factor that cures pellagra, now known to be identical with nicotinic 

 acid, but subsequently it came to be used to denote the rat growth 

 factor, riboflavine. 



The situation was further complicated by the production in dogs ^ 

 of a deficiency disease known as canine blacktongue, so-called from 

 one of its characteristic manifestations ; the diets used were similar 

 to those required to produce rat " pellagra ". Up to the end of 1934 

 it appeared probable that this condition, like rat " pellagra ", was due 

 to a deficiency of riboflavine, but in 1935-36 several workers ^ showed 



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