Effect of high concentration carbon dioxide preconditioning on lipid peroxidation daring myocardial ischemia-reperfusion in rabbits / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effect of high concentration carbon dioxide preconditioning on lipid peroxidation during myocardial ischemia-reperfusion (I/R) in rabbits. Methods Twenty-four New Zealand white rabbits weighing 2.0-3.9 kg were randomly divided into 3 groups ( n = 8 each) sham operation group (group S) , I/R group, high concentration carbon dioxide preconditioning group (group H) . The amimals were tracheal intubated and mechanically ventilated. In groups S and I/R, fresh gas flow was set at 0.3 L/min (100% O2 ), respiratory rate 30-40 bpm and tidal volume IS ml/kg, and PETCO2 was maintained at 40-50 mm Hg for 30 min. In group H, fresh gas flow was set at 0.3 L/min (100% O2), respiratory rate 20-30 bpm and tidal volume 10 ml/kg, PETO2 was maintained at 75-85 mm Hg for 5 min, and then all the ventilatory parameters were adjusted to the same as those in groups S and I/R. Myocardial I/R was produced by occlusion of left anterior descending branch of coronary artery for 30 min followed by 3 h reperfusion after preconditioning in groups I/R and H. The animals were sacrificed at the end of reperfusion and myocardial tissues obtained for determination of the superoxide dismutase (SOD) activity and malondialdehyde (MDA) content and examination of the ultrastnicture of myocardium with the transmission electron microscope. Results The SOD activity was significantly lower, while MDA content higher in group I/R than in group S ( P ＜ 0.01) . The SOD activity was significantly higher, while MDA content lower in group H than in group I/R ( P ＜ 0.01) . The myocardial injury was attenuated in group H compared with group I/R. ConclusionHigh concentration carbon dioxide preconditioning can reduce myocardial I/R injury in rabbits through inhibiting lipid peroxidation.