The protective effects of a phosphodiesterase 5 inhibitor, sildenafil, on postresuscitation cardiac dysfunction of cardiac arrest: metabolic evidence from microdialysis

摘要

IntroductionRecent experimental and clinical studies have indicated the cardioprotective role of sildenafil during ischemia/reperfusion injury. The aim of this study was to determine, by obtaining metabolic evidence from microdialysis, if sildenafil could reduce the severity of postresuscitation myocardial dysfunction and lead to cardioprotection through beneficial effects on energy metabolism.MethodsTwenty-four male piglets were randomly divided into three groups: sildenafil (n?=?8), saline (SA; n?=?8) and sham operation (n?=?8). Sildenafil pretreatment consisted of 0.5?mg/kg sildenafil administered once intraperitoneally 30?minutes prior to ventricular fibrillation (VF). The myocardial interstitial fluid (ISF) concentrations of glucose, lactate, pyruvate, glutamate and glycerol were determined by microdialysis before VF. Afterward, the piglets were subjected to 8?minutes of untreated VF followed by 15?minutes of open-chest cardiopulmonary resuscitation. ISF was collected continuously, and the experiment was terminated 24?hours after resuscitation.ResultsAfter 8?minutes of untreated VF, the sildenafil group exhibited higher glucose and pyruvate concentrations of ISF and lower lactate and glutamate levels in comparison with the SA group, and these data reached statistical significance (P?