Effects of p38 Inhibitor on the Immune Cells in Irradiated Mice

Objective:To observe the effects of p38 inhibitor SB203580 (SB) on the immune cells in mice exposed to 6 Gy irradiation. Methods:Thirty C57BL/6 mice were randomly divided into control group, irradiated group and SB group (n=10 for each). Mice of control group received sham irradiation, and the rest accepted 6 Gy total body irradiation. Mice in SB group were intraperitoneally injected 15 mg/kg of SB every other day for 5 times after irradiation. Mice of other two groups were treated with reference solution. Ten days after mice exposed to irradiation, the white blood cells (WBC) were counted. The immune cell phenotypes in peripheral blood were analyzed by flow cytometry. The levels of reactive oxygen species (ROS) of bone marrow cells were detected. Results:Compared to the control group,the proportion of CD8, B220 and WBC were significantly decreased in the irradiated mice, and the ROS level of bone marrow cells were significantly increased (P 0.01). Compared to the irradiation group, the CD8 ratio was significantly increased in SB group, and the level of ROS in bone marrow cells was significantly decreased in SB group (P 0.05). Conclusion:The results indicate that p38 inhibitor can protect the immune cells from radiation injury by lowing ROS levels.