REDOX STATE OF NICOTINAMIDE NUCLEOTIDES AND ANTIOXIDANT ENZYME ACTIVITIES IN C-27 HEPATOMA TISSUE AND LIVER OF TUMOR-BEARING RATS

Veliky M.M., Vovk O.I., Aphonyushkin T.A., Zababurina M.L., Gurska N.I., Drobot L.B.

The relationships between the redox state of nicotinamide nucleotides, lipid peroxidation, and antioxidant enzyme activities in both liver of tumor-bearing rats and C-27 hepatoma tissue have been studied. It was found that tumor tissue exhibited low content of oxidized forms of nicotinamide nucleotides (NAD⁺ and NADP⁺ ) and lowered ratio of free NAD⁺ /NADH and NADP⁺ /NADPH in cell cytosol as well as low lipid peroxidation level and inhibition of superoxide dismutase and catalase activities. Similar but less significant changes occurred in the liver of tumor-bearing rats. The increase in glutathione peroxidase and glutathione reductase activities in both liver of tumor-bearing rats and C-27 hepatoma tissue suggests that exactly these enzymes play a leading role in antioxidant defense system in tumor-bearing hosts.