The Journal of Vitaminology 4, 1-13 (1958) the Toxopyrimidine Group Substances1

Since Pollack (1) first noticed the urinary excretion of pyramine following in jection of 100mg of thiamine, several investigators (2, 3) have reported a similar finding. Pyramine was assumed by Mickelson (4-6) to be 2, 5-dimethyl-4aminopyrimidine or some compound related to it. Makino et al., on the other hand, have shown in mice and rats that a com pound with a similar structure, 2-methyl-5-hydroxymethyl-4-aminopyrimidine (OMP) induces the so-called running fit, which is suppressed by vitamin B6 (8, 9). They showed further that long term administration of OMP resulted in the appearance of vitamin B6 deficiency symptoms, which could be prevented by vitamin Bb (10, 11). Detailed studies, however, have not been conducted on the quantitative relationship between the running fit and the suppressive effect of vi tamin B6. In this paper, the quantitative relationship between OMP and vitamin B6 was studied. The toxicity of five pyrimidine derivatives with structures si milar to OMP and the effect of vitamin B6 on these substances was also examined .