Abstract: Objective To investigate the changes of excitability of rats′ gastrocnemius after rats were died from mechanic asphyxia, so as to make an objective evidence for estimating of the early postmortem interval. Methods After rats were sacrificed by mechanic asphyxia, the reaction of rats′ gastrocnemius to variable electric stimulation at different period after death were recorded by electricphysiological method.Results Changes in the properties of excitable tissue to electric stimulate in rats′ gastrocnemius after mechanic asphyxia seems to be well correlated with the early postmortem interval and appeared a linear relation in certain period. Conclusion The regular changes of excitability in muscle might be a useful means for estimating of early postmortem interval.

Key words: estimating of postmortem interval, gastrocnemius, electric excibility, forensic medicine