Nicotinic Acid and Prevention of Nutritional Panmyelophthisis in Rats

Abstract

Recently attention has been focused from different angles on nicotinic acid and nicotinicamide. The importance of nicotinic acid in tissue metabolism as a co-enzyme 1 , 2 and as an agent for promoting'growth in bacteria 3 , 4 has been recognized. Furthermore, Funk 5 stated that nicotinic acid, especially nicotinicamide, produced in rats and pigeons kept on a diet devoid of the vitamin B₂ complex “a much larger food intake and better weight, as compared with the controls.” Even in the absence of substantiating details, the latter observations made it probable that nicotinic acid might constitute a separate factor in the vitamin B₂ complex.

While in my own unpublished experiments nicotinic acid had no effect in acrodynia in rats (vitamin B₆ deficiency disease 6 ) either on the skin manifestations or on the growth rate, Elvehjem and his coworkers 7 have succeeded in demonstrating the specific antiblack-tongue activity of nicotinic acid and nicotinicamide in dogs. The therapeutic effect of nicotinic acid is not confined to canine black-tongue; it has been shown 6 , 8 to apply equally well to human pellagra. Thus the long-assumed pathogenetic identity of these 2 diseases is finally proved. In the light of these observations nicotinic acid and its derivative, nicotinicamide, can be accepted as the specific anti-blacktongue or pellagra-preventing factor. This conclusion bears out the circumstantial evidence presented in previous experiments, 9 according to which vitamin B₆ and the P-P factor must represent different constituents of the vitamin B₂ complex.