OBJECTIVETo investigate the expression profile of interleuki-1β (IL-1β) in rat myocardium at different time points during hypoxia/reoxygenation(H/R)transition.

METHODSThe isolated Langendorff perfused rat heart model was established.Forty SD rats were randomly divided into sham group (A group) and hypoxia/reoxygenation group (H/R group). The H/R group rats were subdivided into H/R 0.5 h group(B group), H/R 1 h group(C group), H/R 2 h group(D group)according to reoxygenation time. The left ventricular development pressure(LVDP), maximal rates of increase/decrease of the left ventricular pressure(±dp/dtmax) were continuously recorded. The concentration of interleukin-1β(IL-lβ) and creatine kinase-MB (CK-MB) in myocardium was measured by ELISA. The mRNA expression of IL-lβ in myocardium was determined by RT-PCR. Microstructure of myocardium was observed under light microscopy.

RESULTSThe value of LVDP and ±dp/dtmax in hypoxia/reoxygenation group rat were significantly lower than that in sham group(P < 0.05). The expression of IL-lβ and CK-MB at protein level and the expression of IL-1β at mRNA level in hypoxia /reoxygenation group were higher than that in sham group(P < 0. 05). There were significant differences of the above parameters among H/R 0.5 h, 1 h, 2 h group(P <0.05). The concentration of IL-1β and CK-MB, the mRNA expression of IL-1β were higher in H/R 2 h group than that of other groups(P < 0.05).

CONCLUSIONThe high expression of IL-Iβ in myocardium after myocardial hypoxia /reoxygenation in rats might lead to. ischemia/reperfusion injury.