Heat shock protein 72 expression in the right ventricle of patients undergoing congenital cardiac surgery

While heat shock protein (HSP) 72 is known as a stress protein, there have been no reports of HSP 72 expression in patients who have undergone surgery for congenital heart disease. Fourteen patients (7 males and 7 females) wh o had undergone surgery for congenital heart disease were studied. The ages of the patients ranged from 2 months to 43 years old (mean 6.5 +/- 10.8 ye ars old; median 3.0 years old). The diagnoses were Tetralogy of Fallot in s even, pulmonary atresia with ventricular septal defect (VSD) in three, comp lex anomalies in three, and VSD in one patient. Histological study and HSP analysis using Western blots and immunostaining with anti-HSP 72 monoclonal antibody were performed for right ventricular muscle samples resected duri ng the surgery. The histological findings showed hypertrophic changes of ve ntricular cardiomyocytes in all samples studied. Western blots detected HSP 72 expression of various degrees in all specimens. Immunostaining using mo noclonal antibody against HSP 72 showed that the protein was present in the nuclei and cytoplasm of cardiomyocytes. In conclusion, although it is diff icult to determine the cause of the "stress" that triggers HSP 72 expressio n in cardiomyocytes, low O-2 saturation and pressure overload might act as a "stress", and the only common factor that induced HSP 72 in every sample was hypertrophy.