- Meeting abstract
- Open Access
Influence of temperature during cardiac operations on myocardial apoptosis
© Current Science Ltd 1999
- Published: 16 March 2000
- Cardiac Operation
- Apoptotic Cell
- Cardiopulmonary Bypass
- Protective Role
- Myocardial Cell
To investigate the influence of temperature (T°) during cardiopulmonary bypass (CPB) on induction of myocardial apoptosis.
Eighteen pigs were assigned to a T° group during CPB: 37°, 28° and 20°C, respectively (n = 6 each). Duration of CPB was 120 min and aortic clamping 60. Cardioplegia was achieved with a single dose of Bretschneider solution (4°C; 30 ml/kg). TNF-α was determined by a pig specific ELISA. Six hours post-CPB, tissue probes of the heart were taken for standard- and immunohistochemistry examinations. Apoptotic cells were detected by an in situ apoptosis detection kit (TUNEL).
TNF-α production during and after CPB was significantly higher in group 37°C than in group 20°C. There was no TNFα production in group 28°C. Histological examination showed that the most important myocardial tissue damage in terms of intertitial edema, leukostasis and necrosis was seen in group 37°C followed by group 20°C while the least important damage was present in group 28°C. There was significantly lesser degree of apoptosis of myocardial cells in group 37°C than in both hypothermic groups.
Hypothermia during CPB induces a reduction of the systemic release of TNFα production and also of myocardial tissue damage. This could be due to increased apoptosis seen in the animals operated on in hypothermia. Apoptosis during cardiac operations could be in part responsible for the protective role of hypothermia.