On the Relationship between Hydroxymethylpyrimidine and Pyridoxine. I

Inhibitory Effect of Pyridoxine on the Convulsion by Hydroxymethylpyrimidine in Mice

Abstract

Examinations were made as to whether the convulsant effect of 2-methyl-4-amino-5-hydroxymethylpyrimidine (OMP) in mice would be suppressed by the pyridoxines and it was found that the action is suppressed by the subcutaneous injection of a mixture of OMP and a minute amount of the pyridoxine group in intact mice. The suppressive effect became stronger in the order of pyridoxamine, pyridoxine, and pyridoxal, suppressing the action in an amount 1/5, 1/100, and 1/200, respectively, of that of OMP. Pyridoxal showed a 50% inhibitory effect even in 1/500 amount. The effect was observed in pyridoxine even on separate subcutaneous injection during 1 hour before to 30 minutes after administration of OMP, or even by oral administration. Such inhibitory effect was also observed by application on the abdominal skin but only when applied 1 hour before the administration of OMP. It was assumed from the similarity of the structures of the pyridoxine group and OMP that there would be a biological antagonism between these two kinds of substances.