Activity of Glutathione Antioxidant System and NADPH-Generating Enzymes in Rats with Experimental Rheumatoid Arthritis.

Induction of rheumatoid arthritis in rats was accompanied by an increase in diene conjugate content and glutathione reductase and glutathione peroxidase activities in muscles and blood serum. These changes can be related to mobilization of the glutathione reductase/glutathione peroxidase system coupled with intensification of free radical oxidation. In addition, activity of glucose-6-phosphodehydrogenase and NADP-dependent isocitrate dehydrogenase increased, which can be related to increased demand of NADPH for the glutathione reductase/glutathione peroxidase system. The content of reduced glutathione in muscles and blood serum decreased, probably, due to its utilization for ROS neutralization. Glutathione transferase activity decreased in rheumatoid arthritis, which can be related to shortness of reduced glutathione developing during oxidative stress. The observed shifts in parameters of free radical homeostasis in rheumatoid arthritis are probably associated with intensification of free radical oxidation.