USE OF RIBOFLAVIN HOMOLOG IN REDUCTION OF SUCCINIC DEHYDROGENASE ACTIVITY IN TISSUES OF HEALTHY RATS

Administration of 7-ethyl-8-methyl-10-(l-D-ribityl)isoalloxazine to weanling rats as their only source of flavin permits a normal rate of growth and development. A concomitant rapid and extensive loss of succinic acid dehydro-genase activity from the liver was observed without any apparent influence on the animals'' health. The loss of enzyme activity in the heart and kidney is not as rapid or as extensive as that in the liver. The livers of rats maintained on a riboflavin-deficient diet until they are near death also show a loss of enzyme activity, but no loss is observed for the hearts and kidneys. The administration of a mixture of flavins consisting of 93% of the homolog and 7% of riboflavin maintains the enzyme activity at higher levels than is found in animals receiving the homolog alone. The health of the animals receiving the homolog is indistinguishable from that of the animals receiving equivalent amounts of riboflavin.