OBJECTIVE: To investigate the expression of caspase-3 during contused skeletal muscle wound healing in rats and to explore the applicability of caspase-3 in wound age estimation. METHODS: Male Sprague-Dawley rats undergone anesthesia with 2% pentobarbital sodium (45 mg/kg) were struck by a single strike at the skeletal muscle of the right leg, then were sacrificed by cervical dislocation at different post-traumatic intervals. The changes of caspase-3 activity were assessed by imunohistochemistry, Western blot and caspase-3 colorimetric assay. The skeletal muscle of non-contusion rat's were used as controls. RESULTS: No caspase-3 was detected in skeletal muscle in the control group. The expression level of caspase-3 in the peripheral area of contused rat skeletal muscle increased gradually and maximized on the fifth day after injury, and then decreased gradually. Caspase-3 was also detected in the regenerated skeletal muscle within 7-14 days after injury. CONCLUSION The expression of capase-3 in the peripheral area of contused rat skeletal muscle indicated that it may play a pivotal role in apoptosis of the wounded skeletal muscle and may be used as a marker for wound age estimation. The expression of capase-3 in regenerating skeletal muscle suggests that caspase-3 activity may be used for skeletal muscle differentiation.
Animals ; Caspase 3/metabolism* ; Contusions/enzymology* ; Forensic Pathology ; Male ; Muscle, Skeletal/injuries* ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Time Factors ; Wound Healing