[Study on the relationship between cytosolic phospholipase A2-gamma activation and myocardial cell injury during cardiopulmonary bypass].

OBJECTIVE: To investigate the relationship between cytosolic phospholipase A(2)-gamma(cPLA(2)-gamma) activation and alteration of myocardial ultrastructure during cardiopulmonary bypass (CPB) in the operation of ventricular septal defect. METHODS: Myocardial tissues from the right atria of 12 patients undergone ventricular septal defect were collected before and after CPB, cPLA(2)-gamma gene expression was detected by reverse transcription-polymerase chain reaction (RT-PCR) and analysis was carried out using gel image analysis software. Meanwhile, alteration of myocardial ultrastructure was observed under electron microscopy. RESULTS: cPLA(2)-gamma gene expressions were statistically significant between two groups (P<0.05), and they were higher in patients after CPB than those prior to CPB. The alteration of myocardial ultrastructure after CPB included hypertrophy of nucleus, swelling under plasma membrane, chromatin margination and dilatation of smooth endoplasmic reticulum (SER) in myocardial cell, structures degeneration, hyperplasia of mitochondria as well as swelling, and myocardial fibre dissolve, etc. CONCLUSION: Increased cPLA(2)-gamma gene expression in myocardial tissue after CPB might play an important role in damage of membrane integrity, energy decompensation and myocardial contraction dysfunction.