The mechanism of kidney transamidinase reduction in vitamin E-deficient rabbits.

A recent investigation by Van Pilsum and Wahman (1) revealed low kidney transamidinase activities in vitamin Edeficient rabbits. One logical mechanism to explain this finding is suggested by the observation that dietary creatine depresses kidney transamidinase activity in rats (2, 3). I f the creatinuria of vitamin E deficiency depresses glycocyamine synthesis by kidney transamidinase while creatine synthesis in the whole animal is normal (1) or increased (4, 5), it would indicate that feedback depression of kidney transamidinase by creatine does not regulate creatine synthesis. It thus seems important to establish the cause of the reduced kidney transamidinase activity in vitamin E-deficient rabbits. Accordingly, we have investigated the mechanism of kidney transamidinase depression by vitamin E deficiency. The evidence obtained supports the hypothesis that the depression is secondary to excessive creatine excretion. A direct effect of vitamin E on transamidinase could not be demonstrated.