A Protective Role of Pyridoxin Against the Toxic Effects of P ∗

Abstract

Summary

Mice placed on pyridoxin-free diets were injected with a single dose of radioactive phosphate (5-6 μc/g). In the animals maintained on a low protein diet (in which symptoms of vitamin deficiency did not appear), the administration of pyridoxin did not affect the survival. On the contrary a marked protection by pyridoxin against the injurious effects of P32 was observed in experiments in which the vitamin deficiency had been made more severe by adding a pyridoxin analog (desoxypyridoxin) to the low protein diet, or by increasing the requirements for the vitamin (high protein diets with added cystine or methionine). In these experiments the differences between the groups receiving and those not receiving pyridoxin were larger than the differences which might result from a simple additive effect of the internal radiation and vitamin deficiency.