The vitamin B2 complex. Differentiation of the antiblacktongue and the “P.-P.” factors from lactoflavin and vitamin B6 (so-called “rat pellagra” factor). Parts I–VI

Abstract

IT is now recognised that the vitamin B complex for rats contains at least three components, The position to date may be represented as follows:'The relation of the human pellagra-preventive factor (P.-P.), as well as of the canine antiblacktongue factor, to these newly differentiated components of the vitamin B2 complex has remained for investigation and forms the subject of the present paper.Past work."Vitamin B " was first split into vitamin B1 (heat labile, antineuritic or anti- beriberi factor) and vitamin B2.The latter by definition is " the more heat-stable, water-soluble dietary factor recently described and named P.-P.('pellagra- preventive') factor by Goldberger, Wheeler, Lillie and Rogers [1926] and found necessary for maintenance of growth and health and prevention of characteristic skin lesions in rats, and considered by the latter workers to be concerned in the prevention of human pellagra" (adopted by the Accessory Food Factors Com- mittee at a meeting on Nov. 14th, 1927).This distinction between the heat- labile and heat-stable fractions of the vitamin B complex is due mainly to the work of Goldberger.It was assumed by Goldberger and his associates [e.g.Goldberger and Lillie, 1926; Goldberger et al., 1928, 1, 2] that the factor which prevents the "pellagralike dermatitis" in the rat is identical with the factor which prevents pellagra in human beings (P.-P.factor) and also with the factor which prevents "black- tongue" in dogs.Goldberger's evidence, essentially, was of a similarity in the distribution and in the heat-stability of these factors, and also of the resemblance (superficially at least) of the lesions produced by their absence.1 The "vitamin B4" of Reader is not included in this scheme.It appears that "vitamin B4 deficiency" can be produced only when the animal is first deprived of vitamin B1 and that it is cured whenever crystalline vitamin B1 is given in sufficiently large dose.In other words " vitamin B4 deficiency" has the appearance of chronic hypovitaminosis B1.As also it is described as a "heat-labile factor" it does not affect our present discussion.[For a discussion of "vitamin B4" see further Kinnersley et al., 1935.]