GLUTATHIONE-PEROXIDASE IN BLOOD OF DIABETIC AND NONDIABETIC BB RATS

The activity of glutathione peroxidase (GPX), an antioxidant selenoenz yme (EC.1.11.1.9.). was investigated in blood of BB rats developing sp ontaneous diabetes mellitus. The activity of the enzyme was significan tly higher in the 4th and 5th inbred generation (G(4-5)) of BB rats as compared with their counter-parts of lower degree of inbreeding (G(1- 3)). Overt diabetes (actual blood glucose over 10 mM) appeared only In 8 out of 25 G(5) animals but oral and intravenous glucose tolerance t ests revealed a gradual worsening of glucose metabolism already in rat s with lower degree of inbreeding. No difference in GPX activity was f ound between diabetic and nondiabetic members of G(5) group. In the wh ole group of 69 rats positive correlation was found between the blood GPX activity and the age. weight and actual blood glucose value of the rats and negative correlation between GPX and the P/F value (ratio of peak blood glucose after intravenous tolerance test and fasting blood glucose). In the diabetic animals the enzyme activity showed inverse relationships whith every measured or calculated parameter of glucose metabolism. Our findings indicate a relationship between age and blood GPX activity of BB rats and suggest the possibility of deleterious ef fect of elevated blood glucose level on the blood GPX activity after d evelopment of overt diabetes.