低氧导致培养心肌细胞Na^+通道基因SCN5A mRNA表达改变

Hypoxia Can Induce the Expression Change in Myocardial Sodium Channel SCN5A Gene at the Level of mRNA in vitro

目的研究低氧培养大鼠心肌细胞Na+通道基因SCN5A mRNA表达的变化,并探讨其与丙二醛(M alond ialhyde,MDA)含量及超氧化物歧化酶(superoxide d ismutase,SOD)活性的关系。方法培养大鼠心肌细胞,检测各组培养液氧分压。用RT-PCR检测SCN5A mRNA表达,检测培养液MDA含量和细胞SOD活性。结果与对照组相比:SCN5A mRNA相对表达量低氧1 h和6 h组显著增高(P<0.001)、低氧12 h和24 h组显著降低(P<0.001);MDA含量显著增高而SOD活性显著降低。结论心肌细胞Na+通道基因SCN5A在低氧1 h和6 h mRNA表达上调,而在低氧12 h和24 h mRNA表达下调,且与脂质过氧化和SOD相关。

Objective To study the change in the expression of SCN5A gene at the level of mRNA in the myocardial sodium channel in neonatal rats subjected to hypoxia and to study the relationship between the expression change and content of lipid peroxidation and SOD activity. Methods The cultured myocardial cells of neonatal rats were divided into five groups and they were cultured under normal condition, and under hypoxic condition for 1, 6, 12 and 24 hours. PO2 of cultured medium was tested in each group. SCN5A mRNA expression was determined by RT-PCR and MDA of cultured medium and SOD of cardiomyocytes were determined at different time points of hypoxic culture. Results PO2 was about 86. 0± 6. 96 mmHg in hypoxic culture and lasted for 24 hours （P 〉0. 05 ）. The expression of SCN5A mRNA was significantly increased 1 hour and 6 hours after hypoxia （P 〈0. 001 ）, but it was decreased 12 and 24 hours after hypoxia. The content of MDA rose significantly, but the activity of SOD was decreased under hypoxic condition. Conclusions Hypoxia can promote the expression of SCN5A mRNA after 1 and 6 hours, but it inhibits the expression of SCNSA mRNA 12 and 24 hours later. The change in the expression was related to lipid poroxidation and SOD activity.