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目的探讨茶多酚对缺血/再灌注心脏损伤的保护作用,并研究心脏能量代谢和心肌细胞钙内流是否参与了心脏缺血/再灌注损伤的保护作用。方法在大鼠Langendorff离体心脏上实施缺血/再灌注各30 min,用一导管经压力换能器连接放大器记录心功能指标;用31P NMR技术测定心脏的能量代谢,全细胞膜片钳技术记录心肌细胞钙内流。结果与对照组比较,茶多酚(2.5 mg/L)能使缺血/再灌注心脏的心室发展压、左心室压最大收缩速率(+dp/dt_(max))、左心室压最大舒张速率(-dp/dt_(max))和冠脉流量显著增加(P<0.05),并显著改善缺血/再灌注心脏的能量代谢,增加心肌ATP和PCr含量(P<0.05)。浓度为2.5和5.0 mg/L的茶多酚均能显著抑制培养心肌细胞的钙内流(P<0.01)。结论茶多酚对大鼠离体心脏缺血/再灌注损伤的保护作用可能与其改善心肌能量代谢、抑制心肌细胞钙内流的作用有关。
Objective To investigate the protective effect of tea polyphenols on myocardial ischemia / reperfusion injury and to investigate whether cardiac energy metabolism and calcium influx in cardiomyocytes are involved in the protective effect of myocardial ischemia / reperfusion injury. Methods The ischemia / reperfusion was performed on Langendorff isolated hearts for 30 min in each group. A cardiac catheter was connected to the amplifier via a pressure transducer to record the cardiac function. The energy metabolism of the heart was measured by 31 P NMR. The whole-cell patch clamp technique Cardiac calcium influx. Results Compared with the control group, tea polyphenols (2.5 mg / L) significantly increased the ventricular development pressure, the maximum systolic velocity of left ventricular pressure (+ dp / dt max), the maximum diastolic velocity of left ventricular pressure (-dp / dt max) and coronary flow (P <0.05), and significantly improved the energy metabolism of the heart and increased the content of ATP and PCr in the myocardium (P <0.05). Tea polyphenols at concentrations of 2.5 and 5.0 mg / L significantly inhibited calcium influx in cultured cardiomyocytes (P <0.01). Conclusion The protective effect of tea polyphenols on myocardial ischemia / reperfusion injury in rats may be related to the improvement of myocardial energy metabolism and the inhibition of calcium influx in cardiomyocytes.