Abstract: AIM: To investigate the protective effect of methylamine irisolidone(MMI)preconditioning on mitochondrial membrane potential in H₂O₂-induced rat cardiomyocytes injury. METHODS: With the pretreatment of methylamine irisolidone for 12 h in the model of H₂O₂-induced injury, the cell viability was determined by MTT assay, and the morphology change was examined with Wright's staining and Giemsa's staining, and the change of mitochondrial membrane potential was analyzed by flow cytometry. RESULTS: Compared with the normal group, the cell viability of model group was significantly decreased (P<0.01). Pretreated with methylamine irisolidone (0.5, 1, 5, 10 μmol/L)the cell viabilities were increased significantly (P<0.05, P<0.01), but MMI 0.1 μmol/L group had the similar cell viability compared with the model group (P>0.05).Moreover, pretreated with methylamine irisolidone (1, 5, 10 μmol/L)the mitochondrial membrane potential were increased (P<0.05, P<0.01), and 10 μmol/L group reduced the cell morphology injury. CONCLUSION: Methylamine irisolidone can improve the morphology injury of cadiocytes induced by H₂O₂ and increase the mitochondrial membrane potential, which can decrease the cadiocyte apoptosis.

Key words: methylamine irisolidone, cadiocyte, mitochondrial membrane potential, oxidative stress, apoptosis