缺氧复氧对培养仔鼠心肌细胞NRF1和mtTFA表达的影响与L-carnitine保护作用

Effects of hypoxia/reoxygenation on expressions of NRF1 and mtTFA mRNA in cultured neonatal rat myocardial cells and protective effects of L-carnitine

Objective To study the mechanism of energy disturbance and protective effects of L carnitine on cultured neonatal rat myocardial cells after hypoxia/reoxygenation(H/R). Methods A model of H/R of cultured myocardial cells was used. Adenylic acid (ATP,ADP,AMP) contents in cultured myocardial cells were determined with high performance liquid chromatography. Cultured myocardial cells NRF1 and mtTFA mRNA expressions were assayed with RT PCR. Results Compared with control, ATP and ADP contents in cultured myocardial cells were significantly decreased after 24 h hypoxia and reoxygenation for 0, 2, 4 and 8 h. Compared with H/R group, ATP content in cultured myocardial cells significantly recovered with L carnitine pretreatment. NRF1 and mtTFA mRNA expression were decreased in cultured myocardial cells after hypoxia for 24 h. After reoxygenation for 2,4,8 h, NRF1 and mtTFA mRNA decreased again. L caritine effectively prevented the decrease of mRNA expressions of NRF1 and mtTFA. Conclusion H/R insult suppresses energy metabolism in myocardial cells and the mechanisms are related to downregulation of NRF1 and mtTFA mRNA expreesions; L carnitine posssesses the protective effect on H/R insult and its protective effect might be due to improve oxidative phosphorylation .