Objective To investigate the apoptosis of renal tubule epithelium after cardiopulmonary resuscitation(CPR)in rats and its possible mechanism.Methods Cardiac arrest was induced by asphyxiation(succinylcholine)and ice-cold 0.5 mol/l KCL in rats,and resuscitation started at 5 minutes after arrest.Forty-eight male SD rats were randomly divided into 6 groups:sham(control group);after cardiopulmonary resuscitation rats were allowed to reperfuse spontaneously for 3 hours,6 hours,12 hours,24 hours and 48 hours(n=8,per group).The apoptosis of renal tubule epithelium was assessed by TUNEL.Fas and Bcl-2 protein expression were observed using immunocytochemistry in every group.Results The apoptosis of renal tubule epithelium was singnificantly increased at 3 hours after resuscitation and peaked at 24 hours(P