Abstract: AIM: To explore the effect of tetramethylpyrazine(TMP) preconditioning on rat myocardium with remote ischemic preconditioning(R-IPC).METHODS: Forty adult male SD rats were randomly divided into five groups: Control(Cont) group, ischemia reperfusion(I/R) group, R-IPC group, TMP group, R-IPC+TMP group. R-IPC and R-IPC+TMP groups were pretreated with R-IPC once a day for three days; TMP and R-IPC+TMP groups were pretreated with 10 mg/kg TMP by intraperitoneal injection once a day for three days. After 24 h of last treatment, the isolated rat hearts were langendorff-perfused and I/R injury model were built. The activities of LDH and CPK in the flow, infarct size, the content of MDA, the activities of SOD, GSH-Px and caspase-3, and apoptosis were assayed.RESULTS: After 24 h of pretreatment with R-IPC or TMP, the increases of activities of LDH and CPK, infarct size, the MDA content and apoptotic index induced by acute I/R injury were reduced, decreases of activities of SOD and GSH-Px were enhanced(P<0.01). These results showed that pretreatment with R-IPC and TMP had delay protective effect. 24 h After pretreatment with R-IPC and TMP, delay protective effect was induced as follows: the results such as the activities of LDH and CPK and infarct size showed up weaker delay proterctive effect compared with the activities of SOD, GSH-Px, caspase-3 and apoptotic index.CONCLUSION: Pretreatment with TMP could effectively enhance the R-IPC on cardiac delay protection against acute I/R injury in rat.

Key words: Tetramethylpyrazine, Ischemia preconditioning, Ischemia/reperfusion injury, Rat