Protective effect of heat-shock protein 27 on myocardium with isoflurane preconditioning in myocardial ischemia/reperfusion injury of myocardium in rabbit

Objective: To investigate the mechanism and the protective effect of heart-shock protein 27 (HSP27) on rabbit myocardium with isoflurane preconditioning in myocardial ischemia/reperfusion (I/R) injury.

Methods: Thirty New Zealand white rabbits were randomly assigned to three groups (each n = 10):(1)Sham operation group (C group); (2)I/R group; (3)Two percent in volume is of isoflurane group (S group). S group was exposed to 2.0% isoflurane-pure oxygen for 2 hours. C group and I/R group were exposed 2 hours to pure oxygen to serve as untreated controls. Twenty-four hours later the rats in I/R group and S group underwent 40 minutes of coronary occlusion followed by 120 minutes of reperfusion. At the end of the reperfusion, infarct size (IS) was defined by Evan's blue and triphenyltetrazolium chloride (TTC) staining. Blood samples were taken from arterial line for determination of malondialdehyde (MDA) levels. Western Blotting was used to determine the expression of HSP27 and nuclear factor-KappaB (NF-KappaB) in myocardium.

Results: Isoflurane preconditioning could decrease I/R induced myocardial infarct size [(19.7 +/- 2.8)% vs.(37.8 +/- 1.7)%]. This was accompanied by an increase in the expression in HSP27 [(84.5 +/- 4.3) gray scale value vs. (53.1 +/- 3.8) gray scale value] and a decrease in NF-KappaB [(58.6 +/- 4.2) gray scale value vs. (119.3+/-5.6) gray scale value] and MDA [(5.24 +/- 0.45)kU/L vs. (9.42 +/- 0.83)kU/L].

Conclusions: The expression of HSP27 induced by isoflurane preconditioning plays an important role in protecting myocardium against ischemia/reperfusion injury.