Effects of hydrogen sulfide on apoptosis of cardiomyocytes after cardiopulmonary resuscitation in a rat model

Objective To explore the effects of hydrogen sulfide (H2S) on apoptosis of cardiomyocytes after cardiopulmonary resuscitation (CPR) in rat models.Methods Forty-five male SD rats were randomly into sham group (n =15),CPR group (n =15) and NaHS group (n =15).Rats of CPR group and NaHS group were operated to induce cardiac arrest by transcutaneous electrical stimulation to epicardium.In NaHS group,NaHS (5 mg/kg) was administrated via the femoral venous line 1 min before CPR.Hemodynamic variables were monitored and obtained continuously.Survival rats were sacrificed at 24 h after restoration of spontaneous circulation and the hearts were removed for analysis by RT-PCR and TUNEL assays.Blood samples were collected and plasma content of cTnT was detected.Results Compared with the CPR group,animals treated with NaHS had improved left ventricular function (P ＜0.01),lower plasma cTnT levels (P ＜0.05) and decreased apoptosis index (P ＜ 0.01) 24 h after ROSC.The expressions of Caspase-3 mRNA,Bax mRNA and Bcl-2 mRNA in CPR group and NaHS group were higher compared with the control group (P ＜0.01).The NaHS group had lower expressions of Caspase-3 mRNA and Bax mRNA (P ＜0.01),but higher expression of Bcl-2 mRNA (P ＜0.05) compared with the CPR group.Conclusions Exogenous (H2S) regulated the expressions of Caspase-3,Bax and Bcl-2 mRNA,thereby preventing apoptosis of cardiomyocytes,inhibiting cTnT release and improving left ventricular function 24 h after CPR. Key words: Cardiopulmonary resuscitation;  Myocardial dysfunction ;  Hydrogen sulfide;  Apoptosis