Abstract: Objective To investigate the changes of collagen and MMPs after β irradiation mimicked by electrons-ray. Methods An animal model of β irradiation injury was established by using linear accelerator electron radiation. The expressions of collagen and MMP1, MMP2, MMP9 were measured. Results After electrons irradiation, the expression and the structure of collagen were changed. MMP1 was increased. The expression of MMP2 and MMP9 were also changed. At first they were decreased and then increased. Conclusion Difficult healing of the wound caused by β irradiation may have a relationship with the collagen change, which may be connected with the activity change of MMP1. At the same time MMP2 and MMP9 can help the wound healing.

Key words: Electrons-ray, Radiation injury, Collagens expression, MMPs