Heat shock protein 60 expression in patients undergoing cardiac operations.

Aim. Cardiomyocytes respond to stress with the expression of different heat shock proteins (HSP). The mitochondrial HSP60 is known to be expressed by various stress factors, including Ischemia and reperfusion. The aim of this study was to investigate if HSP60 is increased in human myocardium after cardiac surgery. Methods. To determine if heat shock protein 60 accumulated in the myocardium of patients undergoing cardiac operations, right atrial samples before and after extracorporeal circulation were excised and immediately frozen in liquid nitrogen. Patients: we obtained 10 sequential right atrial specimens from 5 male patients in sinus rhythm undergoing elective cardiac surgery. Measures: the HSP60 protein level was determined by SDS-PAGE, Western blot and quantified by optical densitometry according to the immunoreactive bands of actin. Results. The HSP60 concentration was unchanged in hearts after a single episode of hypothermic ischemia and reperfusion. Immunoblot analysis demonstrated HSP60 expression in all hearts. There was no correlation with the endurance of cardiopulmonary bypass or reperfusion time. Conclusion. These findings indicate that myocardial HSP60 of patients undergoing cardiac operations is not increased after an obligatory period of ischemia, cardioplegic arrest and reperfusion. This might reflect an effective cardioprotection during ECC.