Effects of emulsified isoflurane preconditioning on myocardial NF-κB activity during ischemia-reperfusion in rats

Abstract

Objective To investigate the effects of emulsified isoflurane preconditioning on myocardial NF-kB activity during ischemia-reperfusion （I/R） in rats. Methods Forty-eight healthy male SD rats weighing 230-280 g were randomly divided into 4 groups with 12 animals in each group： sham operation group （group S）, I/R group, lipid emulsion ＋ I/R group （group L） and emulsified isoflurane ＋ I/R group （group EI）. In group I/R, EI and L, myocardial I/R was produced by occlusion of left coronary anterior descending artery （LAD） for 30 rain followed by 120 rain reperfusion. In group L, 30% lipid emulsion 4 ml·kg^-1·h^-1 was infused intravenously for 30 min before myocardial I/R. In group EI, emulsified isoflurane 4 ml·kg^-1·h^-1 was infused intravenously for 30 min followed by 15 min washout before myocardial I/R. In group S and I/R, normal saline was given instead. Blood samples were taken from femoral artery at the end of 120 min reperfusion for determination of serum cTnI and IL-6 concentrations and CK-MB activity by ELISA. The rats were then killed and the myocardial tissues were taken for determination of NF-kB activity by Western blot and observation of the ultrastructure by electron microscopy. Results The NF-tcB activity, serum cTnl and IL-6 concentrations and CK-MB activity were significantly higher in group I/R, EI and L than in group S （ P 〈 0.05 or 0.01 ）, while lower in group EI than in group I/R （ P 〈 0.05 ）. Microscopic examination showed that emulsified isoflurane significantly attenuated the histopathological changes in group EI. Conclusion Emulsified isoflurane pretreatment can attenuate myocardial I/R injury through decreasing the NF-kB activity and inhibiting inflammatory response in rats. Key words: Isoflurane ; Myocardial reperfusion injury ; NF-kappa B