心房颤动患者心房肌浆网ryanodine受体、1,4,5-三磷酸肌醇受体mRNA表达变化的研究

Changes of IP_3 and ryanodine receptors mRNA expression in sarcoplamic reticular in patients with atrial fibrillation

目的 研究心房颤动 (房颤 )患者肌浆网钙释放通道 :ryanodine受体 (ryanodinereceptortype 2 ,RyR2 )及 1,4,5 三磷酸肌醇受体 (1,4,5 trisphosphaterinositolreceptor,IP3 R1)mRNA表达的改变 ,探讨房颤时心肌细胞浆Ca2 + 超负荷的原因。方法 38例风湿性心脏病二尖瓣狭窄接受外科手术者 ,手术时取右心房及右心耳各约 10 0mg ,通过逆转录 聚合酶链反应技术 ,以GAPDH为内参照 ,测量RyR2 及IP3 R1mRNA的变化。结果 房颤患者肌浆网RyR2 和IP3 R1mRNA较窦性心律者上调 ,心房不同部位无差别。地高辛、卡托普利、美托洛尔等药物对RyR2 和IP3 R1mRNA水平表达无明显影响。结论 房颤患者RyR2 和IP3 R1上调 ,说明心肌细胞浆Ca2 + 超负荷与肌浆网钙库的释放增加有关。

Objective To investigate the changes of mRNA expression of calcium releasing channels - ryanodine receptor (RyR_2) and IP_3-I receptors (IP_3R_1) of sarcoplamic reticular and to explore the mechanisms of intracellular calcium overload in patients with atrial fibrillation (AF). Methods Approximately 100 mg tissue each was obtained from the right appendage and the right atrium respectively of the 38 patients with mitrial stenosis who underwent open heart surgery. The changes of IP_3R_1 and RyR_2 were measured by reverse transcription - polymerase chain reaction (RT-PCR) and normalized to the glyceraldehyde 3-phosphate dehydrogenase (GAPDH). Results Up-regulation of RyR_2 and IP_3R_1 mRNA was found in AF patients without difference among different parts of the atrium. Digoxin, captopril, metoprolol had no effect on the levels of RyR_2 and IP_3R_1 mRNA expression. Conclusion RyR_2 and IP_3R_1 mRNA in AF patients have been found to be up regulated, indicating that calcium overload in sarcoplamic reticular might be associated with the release of intracellular stored calcium.