损害性因素对乳鼠心肌细胞甘氨酸受体α1亚基表达的影响

目的：研究脂多糖（LPS）、缺氧/复氧（H/R）、异丙肾上腺素(ISO)以及高糖（HG）对乳鼠心肌细胞甘氨酸受体α₁亚基（GlyRα₁）表达的影响。方法：体外培养乳鼠心肌细胞，分别用LPS、H/R、ISO以及HG处理，采用CCK-8试剂检测细胞活力，RT-PCR方法检测心肌细胞上GlyRα₁亚基mRNA的表达。结果：LPS（5 mg/L、10 mg/L、20 mg/L、40 mg/L、80mg/L）、ISO（20 μmol/L、100 μmol/L、500 μmol/L）以及HG（25 mmol/L、50 mmol/L）处理心肌细胞24 h与心肌细胞缺氧3 h/复氧3 h、单纯缺氧3 h对心肌细胞存活率无明显影响（P＞0.05）；LPS（5 mg/L、10 mg/L、20 mg/L、40 mg/L、80 mg/L）、缺氧（3 h）/复氧（3 h）、单纯缺氧（3 h）以及ISO（20 μmol/L、100 μmol/L、500 μmol/L）组心肌细胞上GlyRα1亚基mRNA表达均高于对照组（P<0.01），而HG（25 mmol/L、50 mmol/L）组心肌细胞上GlyRα₁亚基mRNA表达均低于对照组（P<0.01）。结论：一定浓度的LPS、ISO与一定时间的H/R、单纯缺氧均可上调乳鼠心肌细胞GlyRα₁亚基mRNA的表达，而HG可下调乳鼠心肌细胞GlyRα₁亚基mRNA的表达。

Harmful factors affect glycine receptor α1 subunit mRNA expression in the neonatal rat cardiomyocytes

AIM: To investigate the effects of lipopolysaccharide, hypoxia/reoxygenation，isoproterenol and high concentration of glucose on glycine receptor α₁ subunit mRNA expression in the neonatal rat cardiomyocytes. METHODS: Isolation of cardiomyocytes from Sprague-Dawley rats aging 1～3 d were performed. Cardiomyocytes （1×10⁵～5×10⁵ cells·L^-1）were cultured in DMEM medium containing 15% fetal bovine serum at 37 ℃ in 5%CO₂ atmosphere for 72 h. Then, cultured rat cardiomyocytes were treated with lipopolysaccharide, isoproterenol or high concentration of glucose for 24 h, respectively, or were exposed to hypoxia for 3 h followed by reoxygenation for 3 h. Subsequently, the cell survival rate was measured using CCK-8 reactant and RT-PCR was applied to monitor the expression of glycine receptor α₁ subunit mRNA. RESULTS: Compared with the control group, no significant difference in the cell survival rate was observed （P＞0.05）. The expression of glycine receptor α₁ subunit mRNA was increased （P＜0.01） in lipopolysaccharide（5,10,20,40,80 mg/L），isoproterenol（20,100，500 μmol/L） or hypoxia/reoxygenation, hypoxia groups, but decreased（P＜0.01）in the group treated with high concentration of glucose（25, 50 mmol/L）. CONCLUSION: Lipopolysaccharide, isoproterenol, hypoxia/reoxygenation or hypoxia upregulates the expression of glycine receptor α₁ subunit mRNA,but high concentration of glucose down-regulates the expression of glycine receptor α₁ subunit mRNA in cultured neonatal rat cardiomyocytes.