Tissue-specific changes in heme oxygenase activity and level of nonprotein thiols in C57Bl/6 mice after whole-body gamma-irradiation

Heme oxygenase catalyzes heme degradation and is an important component of the antioxidant defense. Nonprotein thiols participate in redox regulation of heme oxygenase gene expression. Changes in heme oxygenase activity and levels of nonprotein thiols in the liver, lungs, and brain of C57Bl/6 mice were studied on days 1-7 after whole-body gamma-irradiation in a dose of 10 Gy. The maximum increase in heme oxygenase activity was observed in the liver (to 196% in females and to 250% in males) and was associated with an 8-fold increase in the level of heme oxygenase-1 (inducible form of the enzyme) mRNA. The increase in heme oxygenase activity was less pronounced in the lungs, while in the brain this parameter slightly decreased. Changes in the levels of nonprotein thiols were sex-dependent: in the liver and lungs this parameter increased in females and decreased in males.