Effect of Riboflavin and Thiamin Chloride upon the Cataractogenic Action of Galactose. ∗

Abstract

In previous work with galactose cataract the usual protective doses of vitamin supplements were provided in accordance with the recognized need of the rat. The normal growth of the rats and the lack of gross evidence of any vitamin deficiency led us to conclude that the cataract was probably due to some metabolic disturbance unrelated to a vitamin. The possibility of an increased demand for certain factors was considered, however. The usual dose of 0.5 g daily of dry yeast was increased fourfold without changing the rate or incidence of cataract. Massive doses of cod liver oil and viosterol made no difference.

The subsequent isolation of pure crystalline vitamins made it possible to supplement our previous findings by feeding massive doses of certain ones which have been shown to have any connection with lenticular changes. A previous paper reported 1 that no change in susceptibility to cataract was observed when large doses of ascorbic acid were administered orally or subcutaneously.

The present investigation using 2 crystalline fractions of the vitamin B complex, riboflavin and thiamin chloride (Betabion) has been made possible through the courtesy of Merck and Company. While no gross symptoms of vitamin B or G deficiency existed, nevertheless, it was possible that the introduction of galactose might have created unusual metabolic demands for one or both of these vitamins which could be recognized only by trying massive doses. So far as is known there is no etiologic factor common to galactose cataract and the vitamin G deficiency cataract first reported by Day, et al. 2 In fact, the statement made in a recent article by Day 3 “that flavin is the cataract-preventive vitamin” may need modifying in view of the present findings.

Four litters (29 rats) were so divided as to allow littermate comparisons and were fed a ration consisting of 25% galactose, 45% cornstarch, 15% vitamin-free casein, 4% salt mixture, 9% Crisco and 2% cod liver oil supplemented as indicated in Table I. Two drops of tikitiki were added to the crystalline supplements to provide the filtrate factor and incidentally to improve the palatability and thus insure complete consumption of the supplement.