Increased folate catabolism following total body gamma-irradiation in mice.

Concentrations of total folates and their oxidative degradate, para-aminobenzoyl glutamic acid, were determined in mouse after 2-7 Gy total body gamma-irradiation (TBI). Total liver folate levels were drastically reduced by almost 47% over a period of 120 h after TBI with 7 Gy. Oxidative damage, splitting the folate molecule into pterin and p-aminobenzoylglutamic acid (p-ABG), was observed after TBI. p-ABG levels, which 24 h after irradiation were raised by 15%, were further elevated to more than three-fold over the control after 120 h. A dose-dependent increase in the oxidative degradation of folate was observed. The oxidative cleavage of folate may be one factor contributing to folate deficiency in radiation stress.