RESUMO
OBJECTIVE: To investigate the morphologic changes of actin in skeletal muscles of rats associated with postmortem interval (PMI). METHODS: The morphologic changes of actin filament in the skeletal muscles (adductor magnus of right hind leg) of 28 rats were observed by laser scanning confocal microscope (LSCM) and transmission electron microscope (TEM) at different postmortem intervals (0, 24, 48, 72, 96, 120 and 168 h). RESULTS: The TEM revealed that actin filament began to disintegrate with the lapse of PMI, and eventually the structure of sarcomere and actin filament disappeared. The LSCM showed depletion of anti-actin antibody staining in the skeletal muscles and the extent of staining decreased with extension of PMI correlatively (Y = 0.934-0.005X, R2 = 0.95, P < 0.05). The content of actin positive products reduced with PMI (P < 0.05). No actin positive products were detected 168 h after death. CONCLUSION: The morphologic changes of actin filament in skeletal muscles may become a useful indicator for the estimation of death time.
