Protective role of heme oxygenase in myocardial dysfunction postresuscitation

Abstract

Objective To study the cardioprotection effects of heme oxygenase-1(HO-1)on cardiopulmonary resuscitation(CPR).Method Male Sprague-Dawley rats were asphyxiated for 9 minutes and resuscitated.Rats wefe randomly divided into 4 groups,namely,sham asphysiation group,CPR group,Hemin group and Heroin +ZnPP group(zinc protoporyphyrin IX).Resuscitated groups were further divided into two subgroups according to various intervals:6 hours and 24 hours after resuscitation.Hemodynamic was observed.Serum creatine phosphokinase-MB(CPK-MB)and lactate dehydrogenase were determined.HO-1 in heart tissue homogenates was assayed.Ultrastructure of rats hearts was examined.Statical evaluation was performed with analysis of variance.Results The mean blood pressure(MBP)in resuscitated groups was significantly reduced after resuscitation,hadn't any difference between supgroups.The scores of dp/dt 40 and-dp/dt were significantly decreased in CPR group and Hemin+ZnPP group after resuscitation(all P＜0.05),but dP/dt40 in Heroin group did nol differ significantly after resuscitation.and-dp/dt decreased only 0.5 hours and one hour after resuscitation and returned to baseline values two hours after resuscitation.The scores of dp/dt 40and-dp/dt in Heroin group at different intervals after resuscitation were significantly higher than those in CPR group and Hemin+ZnPP group(all P＜0.05).Serum CPK-MB and LDH in CPR group and Hemin+ZnPP group at 6 hours and 24 hours after resuscitation were significantly higher than those in Hemin group(all P＜0.05).The cardiac tissue ultrastructure of rats in Hemin group was more intact than that of CPB group and Hemin+ZnPP goup.HO-1 levels in heart tissue homogenates of Hemin group at 6 hours and 24 hours after resuscitation were significantly higher than those in CPR group and Heroin+ZnPP group(all P＜0.05).Conclusions HO-1 expression induced by Heroin can effectively improve post-resuscitation myocardial dysfunction,alleviate cardiac injury,keep the ultrassructure integrity of cardiac myocytes.It may be a new approach to treat myocardial dysfunction after resuscitation. Key words: Heme oxygenase; Cardiopulmonary resuscitation; Myocardial dyfunction; Rat