Comparison Of Heptanol Precondictioning, Hypioxic Preconditioning And Hypoxic Postconditiong By Cx43 Of Myocardial Mitochondria On Anoxia/Reoxygenation Injury In Rat Myocardium Cells

Nowadays, ischemia-reperfusion (I/R) injury has become one of the important problems in the treatment of coronary heart disease. Many studies have shown that gap junction intercellular communication involved in I/R injury. The ways targeting gap junction against I/R may be a new direction. Heptanol, as a gap junction blocker, it's mechanism against I/R is unclear, especially by Cx43 of myocardial mitochondria, which has not been reported in the domestic and foreign literature. For the above, this topic is to establish models of rat's myocardial anoxia-reoxygenation, and determine content and apoptosis of mitochondria Cx43 after heptanol preconditioning, compared with hypoxic precongdictioning and hypoxic postcondictioning. Objective: To investigate the effects of different concentration heptanol precondictioning on Connexin43 (Cx43) of cardiac muscle sarcolemma and mitochondria Cx43 in rat's myocardium cells model of anoxia/reoxygenation.Methods: The myocardium cells which isolated from SD neonatal rats and cultured were divided randomly into 7 groups, namely: normal control group (control group), anoxia/reoxygenation group (AR group), DMSO group, 0.1mmol/LHT group (0.1HT group), 0.5mmol/LHT group (0.5HT group), 1.0mmol/LHT group (1.0HT group), 2.0mmol/LHT group (2.0HT group). Each group was intervened appropriately before anoxia/reoxygenation except control group. The content of mitochondria Cx43-GJ were determined by Western Blot. Cx43mRNA levels were assayed by RT-PCR.Results: Compared with group control, the sarcolemma and mitochondria Cx43-GJ expression was distinctly decreased in group AR, group 0.1HT and group 0.5HT(P<0.01). Compared with group AR, the change of mitochondrial Cx43-GJ content and Cx43mRNA was milder in group 1.0HT and group 2.0HT(P<0.01). No significant difference was found between group group AR, group 0.1HT and group 0.5HT(P>0.05).Conclusions: Heptanol preconditioning can reverse sarcolemma and mitochondria Cx43 decreases induced by AR, but it's affected by concentration of heptanol. As sarcolemma Cx43, mitochondria Cx43 may be involved in the myocardial protection of heptanol preconditioning .Objective: To investigate the effects of heptanol precondictioning, compared with hypoxic preconditioning and hypoxic postconditioning, on anoxia/reoxygenation injury by Connexin43 (Cx43) of mitochondria in rat myocardium cells.Methods: The myocardium cells which isolated from SD neonatal rats and cultured were divided randomly into 6 groups, namely: normal control group (control group), anoxia/reoxygenation group (AR group), DMSO group, hypoxic preconditioning group (HP group),hypoxic postconditioning group (PC group),heptanol group (HT group). Each group was intervened appropriately before anoxia/reoxygenation except control group and PC group. PC group was intervened after AR. The cellular apoptosis were examined by flow cytometry, and Cx43mRNA levels were assayed by RT-PCR. The content of mitochondria Cx43-GJ were determined by Western Blot.Results: Compared with group control, the cellular apoptosis increased distinctly in group AR, at the same time, the membrane and mitochondria Cx43-GJ expression was distinctly decreased(P<0.01). Compared with group AR, the change of mitochondrial Cx43-GJ content and Cx43mRNA was milder in group HP, group PC and group HT, while the cellular apoptosis decrease(P<0.01). No significant difference was found among group IP, group PC and group HT(P>O.05).Conclusions: By affected mitochondria Cx43, heptanol preconditioning can, as HP and PC, protect myocardium cells on anoxia/re-oxygenation injury in rat myocardium cells.