A new factor in the production and cure of macrocytic anaemias and its relation to other haemopoietic principles curative in pernicious anaemia,

Abstract

Crude extracts of liver, yeast, marmite and wheat germ are curative, some only after mixing with normal gastric juice, both in pernicious anaemia in man and in the nutritional macrocytic anaemia of monkeys, a condition regarded as the animal counterpart of tropical macrocytic anaemia. More highly purified extracts of the liver principle e.g., anahaemin (Dakin and West) and examen (Laland and Klem) are inactive in the monkey anaemia although retaining activity in pernicious anaemia in man. The liver extract campolon is fractionated by (NH4)SO4 into an insoluble fraction containing the anahaemin-like material which is curative in true pernicious anaemia but inactive in the monkey condition and a soluble fraction which is highly active in both conditions. Tyrosine and hexa-toflavin are inactive in the monkey anaemia. The monkey factor cannot be Castle''s extrinsic factor. It is extracted from yeast by dilute acetic and it resists autoclaving at pH 5 for 5 hrs. at 120[degree], it is not precipitated by 80% ale. nor by saturated (NH2)2SO4 and is not adsorbed by Fuller''s Earth. The relation of the factor to a fraction of the vitamin B2 complex is discussed, and a certain amt. of evidence is brought forward suggesting that the anaemia-like and the monkey factor are both required in both conditions but that in true pernicious anaemia the former and in the monkey anaemia the latter is usually more deficient.