Abstract:  Objective To investigate the relationship between wound age and the expressions of frizzled-2 （Fzd2） mRNA and its protein in rats skeletal muscle after contusion, and to explore its possibility of being an index for wound age estimation. Methods The mRNA and protein expressions of Fzd2 in rats skeletal muscle of the control group and the experimental group within 4-48 h after contusion were detected per 4 h by RT-qPCR and Western blotting. Results The relative expression of Fzd2 mRNA increased at 24 h, 36 h and 40 h after contusion, and the expression at 24 h was twice as the control group （P<0.05）. The relative expression of Fzd2 protein changed inconspicuously after contusion （P>0.05）. Conclusion The changes of Fzd2 mRNA expression after contusion in a certain time can be a basis to estimate wound age by combined multi-indicators.

Key words: forensic pathology, wound age estimation, frizzled-2, skeletal muscle contusion