Abstract: Objective To investigate the expression of cannabinoid receptor Ⅰ（CB1R） during mice skin incised wound healing course and time-dependent changes of CB1R in wound age determination. Methods The changes of CB1R expression in skin incised wound were detected by immunohistochemistry and Western blotting. Results The control group showed a low expression of CB1R detected mainly in epidermis, hair follicles, sebaceous gland and dermomuscular layer. CB1R expression was undetectable in neutrophils in the wound specimens from 6 h to 12 h post-injury. CB1R positive cells were mostly mononuclear cells（MNCs） and fibroblastic cells（FBCs） from 1 d to 5 d post-injury. CB1R positive cells were mostly FBCs from 7 d to 14 d post-injury. The ratio of the CB1R positive cells increased gradually in the wound specimens from 6 h to 3 d post-injury, reached peak level at 5 d, and then decreased gradually from 7 d to 14 d post-injury. The positive bands of CB1R were observed in all time points of the wound healing course by Western blotting. The expression peak showed at 5 d post-injury. Conclusion CB1R is activated during the wound healing course. The expression of CB1R is found in mononuclear cells, which could be involved in inflammation reaction. CB1R is observed in fibroblastic cells, which could participate in the wound healing. CB1R may be a potentially useful marker for determination of wound healing age.

Key words: forensic pathology, wound healing, skin, receptor, cannabinoid, CB1, mice