Role of AMPK signaling pathway in sevoflurane preconditioning-induced enhancement of antioxidant capacity during hypoxia-reoxygenation in cardiomyocytes of rats

Objective To investigate the role of 5'-AMP-activated protein (AMPK) signaling pathway in sevoflurane preconditioning-induced enhancement of antioxidant capacity during hypoxia-reoxygenation (H/R) in the cardiomyocytes of the rats.Methods The rat embryonic cardiomyocytes (H9C2 cells) were randomly divided into 3 groups (n =12 each) using a random number table:control group (group C),H/R group,and sevoflurane preconditioning group (group SP).AMPK gene knockout (AMPK siRNA) H9C2 cells were randomly divided into 3 groups (n =12 each) using a random number table:control group (group A-C),A-H/R group,and sevoflurane preconditioning group (group A-SP).The cells were exposed to 95％ N2 + 5％ CO2 in an incubator for 14 h followed by reoxygenation with 95％ O2 + 5％ CO2 for 3 h.In SP group,the cells were preconditioned with 15 min sevoflurane (final concentration 2.0 mmol/L) three times at 15 min interval and H/R model was established at 15 min after the end of preconditioning.At 3 h of reoxygenation,the level of superoxide anion was detected using lucigenin-enhanced chemiluminescence and DHE staining,and the release of dehydrogenase (LDH) and caspase3 activity were measured.Results Compared with group C,the release of LDH and level of superoxide anion were significantly increased,and caspase-3 activity was enhanced in group H/R.Compared with group H/R,the release of LDH and level of superoxide anion were significantly decreased,and caspase-3 activity was weakened in group SP,and the release of LDH and level of superoxide anion were significantly increased,and caspase-3 activity was enhanced in group A-H/R.Compared with group SP,the release of LDH and level of superoxide anion were significantly increased,and caspase-3 activity was enhanced in group A-SP.Compared with group A-H/R,the release of LDH and level of superoxide anion were significantly decreased,and caspase-3 activity was weakened in group A-SP.Conclusion AMPK signaling pathway is involved in the mechanism by which sevoflurane preconditioning enhances the antioxidant capacity during H/R in the cardiomyocytes of the rats,but it does not play a major role. Key words: Protein kinases;  Anesthetics, inhalation;  Myocardial reperfusion injury;  Antioxidants;  Ischemic preconditioning