The effect of 1,3 bis-(2-chloroethyl)-1-nitrosourea on rat brain glutathione status under conditions of normoxia and hyperoxia.

The effect of inhibition of rat brain glutathione reductase, under conditions of normoxia and hyperoxia, on tissue ratios of reduced:oxidized glutathione was tested. Under conditions of normoxia, inhibition of brain glutathione reductase by approximately 50%, had no effect on reduced or oxidized glutathione in any of the three brain regions analyzed. After exposure of rats to 4 ATA 100% oxygen for one hour, in the presence of the same degree of enzyme inhibition, significant increases in oxidized glutathione in the cortical and subcortical areas of the brain were detected. Coupled with small, but nonsignificant decreases in reduced glutathione, a highly significant decrease in the ratio of reduced:oxidized glutathione was demonstrated in these two brain regions. These results indicate that under the conditions of an increased oxidizing environment, inhibition of brain glutathione reductase enhances the oxidative stress experienced by this organ.