Evidence of Another Factor in the B Complex for Rats

Abstract

B₁ (Thiamin), flavin, nicotinic acid, B₆, and the filtrate factor are generally accepted as distinct components of the B complex for rats. Recent work on other species of animals by Morgulis, Wilder, and Eppstein 1 and by Jukes and Babcock 2 indicates that antimuscular dystrophy and antiparalytic factors exist, while Stockstad 3 reports evidence of a distinct growth factor U for the chick.

The work herein reported has been confined to the differentiation of the various factors of the B complex which are necessary for the rat. Three-weeks-old rats of 30 to 35 g weight were placed in groups of 6 in screen bottom metal cages and received weighed amounts of the supplemented diets furnishing the desired quantity of each supplement per day. The basal ration contained 60% alcoholic extracted washed casein 18.0, salt mixture 3.7, cod liver oil (Squibb) 4.0, and sucrose to 100%. Three and one-half percent of water was added to prevent rancidity. The washed casein was prepared by washing commercial casein 14 days with 0.15% acetic acid and decanting daily. From this casein was prepared the alcoholic extracted casein by extracting in a continuous extractor with 60% alcohol for 4 days.

Concentrates of filtrate I (B₆) and filtrate II (FII) were prepared from liver and from rice polish by the method of Lepkovsky, Jukes and Krause. 4 The B₆ concentrate was purified further by readsorption and elution before concentration. Both B₆ and FII fractions were found necessary in addition to B₁, flavin, and nicotinic acid for the growth and well being of the rat. Omission of nicotinic acid in diets with 0.3 g of alfalfa plus washed casein or with 0.3 g alfalfa plus 8B as a source of total filtrate resulted in decreased growth showing that nicotinic acid is essential for rat growth and that this substance is deficient in 0.3 g of alfalfa, in washed casein, and in 8B concentrate.