Alteration Of S-100B In Serum And Brain Following Whole-brain Irradiation In Rats

Objective: To investigate the change of S-100B in serum and brain in SD rats at various times after exposure to different whole-brain irradiation doses. To explore the characteristics of the S-100B change in early radiation-induced brain injuries.Methods: A model of brain radiation-induced injuries was established in the SD rat after whole-brain irradiation with a single dose of 2, 10, or 30 Gy of 4MeV electron generated by Philips SL-18 accelerator. The concentration of S-100B in serum was detected by means of enzyme-linked immunosorbent assay (ELISA) at different time points (1 hour, 6hours, 12hours, 24hours, 3 days, 1 week, 1 month) after exposure. The expression of S-100B in brain tissue at the same time points was analyzed by immunohistochemistry.Results: The serum concentration and brain expression are not strongly correlated (correlation is 0.452). The group with sham irradiation and no anaesthesia is not different from the group with anaesthesia and sham irradiation in both serum and brain tissue measures. For serum concentration, it seems that the higher the dose, the higher the serum concentration and the differences between the dose groups are significant (via multiple regression models). In terms of measuring time points, the serum concentration in all groups reached the first peak 6 hours after irradiation, declined after 12 hours, rose again after 24 hours, and started to decline again until the last time point (1 month), with the exception of the 2Gy group, which reached the second peak at 3 days after irradiation. For brain expression, the higher the dose, the higher the measurement, and different dose groups have significantly different results.Conclusion: The S-100B serum concentration and the brain expression change after the SD rats receive whole-brain irradiation and these changes are positively related to the irradiation amount, the serum concentration in all groups reached the first peak 6 hours after irradiation, declined after 12 hours, reached the second peak at 1- 3 days .The S-100B may play an important role in the course of brain irradiation injury in rats, and may be a valuable serum marker for the brain irradiation injury.