Cx . on Catatorulin . a New Method of Comparing the Oxidative Factor in Vitamin B

IN recent work Gavrilescu, Meiklejohn, Passmore and Peters [1932] have shown that potent vitamin B1 concentrates in very small amount increase the oxygen uptake of avitaminous pigeon's brain in lactate solutions. The effect is proved to be catalytic, because the extra oxygen taken up is far in excess of the amount of vitamin B1 added. To avoid begging the question as to the identity of the oxidase factor in the concentrates with vitamin B1, and to economise words, we prfopose to call it "catatorulin." There is very strong evidence to support the view that catatorulin and vitamin B1 are identical. In particular Meiklejohn, Passmore and Peters [1932, 1, 2] found that the catatorulin effect was directly related to the well-known symptom of head retraction in pigeons, and that it disappeared with cure of the birds by vitamin. The indirect evidence in favour of identity is strengthened by the fact, presented here for the first time, that the crystalline preparations of Kinnersley, O'Brien and Peters [1933] exhibit catatorulin action. Nevertheless these workers are not yet convinced that the crystals represent pure vitamin, and therefore any finding of parallelism between catatorulin and vitamin B1 preparations is of importance. With these objects in view, a method has been devised for comparing the effects upon oxygen uptake of two different vitamin B1 preparations. Avitaminous brain tissue must be used because the normal shows no effect with added vitamin B1. Attempts to obtain stable dry preparations so far have failed. There has proved to be good correspondence between vitamin B1 and catatorulin in the crystalline preparations; the method therefore promises to be of value as a new means of estimating the activity of potent vitamin B1 preparations. It has the great advantage that bird variations are eliminated, and that a comparison is made upon an enzyme system rather than upon the whole animal. EXPERIMENTAL.