Objective To observe the effect of electroacupuncture(EA)and moxibustion(Moxi)pretreatment on expression of myocardial heat shock protein(HSP)in acute myocardial ischemia-reperfusion injury(MIRI)rabbits.Methods A total of 72 New Zealand rabbits were randomly divided into 4groups:sham operation

MIRI model

EA pretreatment and Moxi pretreatment(n=18rabbits in each group)which were further divided into 0

24 and 48h(time-point)subgroups(n=6in each).The MIRI model was established by occlusion of the anterior descending branch(ADB)of the left coronary artery for 40 min and reperfusion for 60 min.EA and Moxi stimulation was respectively applied to bilateral"Neiguan"(PC 6)for 20 min

once daily for 5days before ADB occlusion.The expressions of myocardial HSP 27

HSP 70 and HSP 90 were detected by immunohistochemistry.The pathological and ultrastructural changes of left ventricular ischemia tissue were observed under light and transmission electronic microscope(TEM)

respectively.Results Outcomes of H.E.staining and ultrastructure showed that MIRI-induced changes of disordered arrangement of cardiomyocytes

vague myocardial transverse striation

inflammatory infiltration

cardiac myofibre necrosis and fibrolysis(light microscope)

and myofiber atrophy

vague and disorder in the arrangement of myofiber

myofilament necrosis

interstitial edema

mitochondrial swelling

microvessel expansion

etc.(TEM)were relatively milder in both EA and Moxi pretreatment groups(48h).In comparison with the sham group

the expression levels of myocardial HSP 27

HSP 70 and HSP 90 had no significant changes after MIRI at the 3time-points(P>0.05).In the pretreatment groups

the expression levels of HSP 27 at 24and 48 hin both EA and Moxi groups

HSP 70 at 48hin both groups

HSP 70 at 0and 24 hin the Moxi group were significantly up-regulated compared with the model group(P<0.05

P<0.01).No significant changes were found in the expression of HSP 90 at the 3time-points in the EA and Moxi pretreatment groups(P>0.05).No significant differences were found between EA and Moxi in up-regulating expressions of myocardial HSP 27

HSP 70 and HSP 90 proteins at the 3time-points(P>0.05)except HSP 70 at 24h(Moxi being stronger relative to EA

P<0.05).Conclusion EA and Moxi pretreatment has a protective effect on ischemic myocardium in MIRI rabbits

which may be associated with their actions in up-regulating myocardial HSP 27 and HSP 70 expression.