ABSTRACT
Objective To compare the changes in nitric oxide (NO), total ability of anti-oxidize antioxidase, superoxide dismutase (SOD), glutathion peroxidase (GSH-PX), catalase (CAT) and maleic dialdehyde(MDA) in rats after single and accumulative 60Co γ-irradiation . Methods 48 rats were randomly divided into two groups of single and accumulative irradiation. Each group was irradiated by 60Co gamma-rays. The total irradiation doses were 0.4, 0.8, 1.6, 3.2 and 6.4 Gy, respectively in each group. The NO, total ability of anti-oxidize antioxidaze, SOD, GSH-PX, CAT and MDA in serum were measured at day 1 after last irradiation. Results Compared with the single irradiation group, the NO (52.6-117.9 μmol/ml), total ability of anti-oxidize antioxidaze (3.3-26.2 U/ml), the antioxidase activity of the SOD (26.3-167.5 U/ml), GSH-PX (740.8-2462.4 U/ml), CAT (3.3-29.4 U/ml) and the content of MDA(29.3-155.1 nmol/ml) of mt serum in accumulative irradiation group were increased after irradiation, which was related with the accumulative irradiation dose. For instance, total ability of anti-oxidize antioxidase (26.2 U/ml), antioxidase activity of the SOD (167.5 U/ml) and CAT (29.4 U/ml) in 0.4 Gy group of accumulative irradiation were significandy increased when compared with those of control group. However, the content of MDA in accumulative irradiation group was obviously higher than that in single radiation group when the irradiation doses delivered over 3.2 Gy, which might be correlated with higher antioxidase activity. Conclusions Low dose of accumulative gamma-rays irradiation can induce the stimulative effect of antioxidase activity. However, higher dose of accumulative gamma-rays irradiation can damage the activity of antioxidase.