Effect of MgSO4 on NMDA receptor in brain tissue and serum NSE in rats with radiation-induced acute brain injury

Objective: To explore the protection of magnesium sulfate (MgSO4) on radiation-induced acute brain injury. Methods Thirty six mature Sprague-Dawley rats were randomly divided into 3 groups: the blank control group, experimental control group and experimental therapy group. The whole brain of SD rats in the experimental control group and experimental therapy group were irradiated with a dose of 20 Gy using 6 MeV electron beam. Magnesium sulfate was injected intraperitoneally into the rats in the experimental therapy group before and after irradiation for seven times. The blood and the brain tissue were taken on the 1st, 3rd and 14th day after irradiation. ELISA was used to measure the level of serum NSE. Western blot technique was used to detect the expression of NR1 and NR2B subunit protein in brain tissue. Results: Compared with the blank control group, the level of serum NSE in the experimental control group increased significantly (P<0.05). The expression of NR1 and NR2B also in-creased. Compared with that in the experimental control group, the level of serum NSE in the experi-mental therapy group was significantly lower since the 3rd day after irradiation (P<0.05). The expression of NR1 and NR2B was lower after irradiation. Conclusions: MgSO4 used in early stage can inhibit the level of serum NSE and the expression of NR1 and NR2B after radiation-induced acute brain injury. It shows a protective effect on radiation-induced acute brain injury. (authors)