Abstract
1) Urinary β-aminoisobutyric acid (BAIBA) excretion level increased remarkably at several days after irradiation to tumor.
This seemed likely to reflect tumor cell destruction.
2) There was a tendency of decreased BAIBA excretion level after long term administration of anti-tumor substances.
These findings were presumably due to decreased thymidine pool in organisms.
3) The ability of BAIBA degradation was higher in genetic low BAIBA excretors than in genetic high excretors.
In the situation of increased BAIBA excretion level, which reflected increased thymine catabolism, there was some differences in BAIBA excretion pattern between low excretors and high excretors; in low excretors, the amount of increased BAIBA excretion was smaller than in high excretors.
