Pretreatment with volatile anesthetics inhibits myocardial apoptosis induced by myocardial ischemia-reperfusion in rabbits / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effects of pretreatment with volatile anesthetics on myocardial apoptosis induced by myocardial ischemia-reperfusion. Methods Forty-eight healthy New Zealand white rabbits of both sexes weighing 3.2-3.5kg were anesthetized with intramuscular ketamine 70mg?kg-1. The animals were tracheotomized and intubated and mechanically ventilated. PaCO2 was maintained at 4-4.5kPa. Sternum was longitudinally splitted. Left anterior descending branch of coronary artery was exposed and mobilized and a fine rubber tube was placed around it for occlusion of the artery. The occlusion of the artery was confirmed by cynosis of the area of myocardium involved and ECG which showed elevation of S-T segment. The animals were randomly allocated to one of 6 groups of 8 animals in each group sham-operation group (P) ; ischemia / preconditioning group (IP) ; and three groups pretreated with isoflurane (I), sevoflurane (S) and desflurane (D) . Each group except group P was subjected to 3h occlusion of left anterior descending artery followed by 3h reperfusion. Group I, S and D were pretreated with inhalation of 1.1% isoflurane, 2% sevoflurane or 6% desflurane for 30 min followed by 15 min washout. The heart was then removed after ischemia-reperfusion. Infarct size and ischemic area were determined by dual staining with triphenyltetrazolium chloride and Evan' s blue. DNA laddering in the border zone of myocardial ischemic area was revealed by agarose gel electrophoresis. Apoptosis index (A I ) was obtained by flow cytometry. Results The infarct size, expressed as the percentage of the ischemic area was (60.8?10.8)% in ischemia-reperfusion group and was greatly reduced in group IP (33.1 ?4.9)%, group I (39.0?5.9)%, group S (30.9 ?6.8)% and group D (32.2? 7.5)% (P