茶黄素降低缺血再灌注损伤大鼠心室肌细胞内游离钙浓度的研究

目的研究茶黄素对大鼠心室肌细胞内游离钙浓度([Ca2+]i)的影响并探讨其可能机制。方法在正常台氏液和模拟缺血液中,用激光共聚焦显微镜探测[Ca2+]i,结果用相对荧光强度表示。结果茶黄素(20μmol/L)对正常台氏液中心室肌细胞内[Ca2+]i有影响,但可降低模拟缺血液中心室肌细胞[Ca2+]i的增加。应用钠钙交换体抑制剂NiCl2(100μmol/L)可模拟茶黄素(20μmol/L)在模拟缺血液中的作用。预先应用肌浆网钙泵抑制剂Thapsigar-gin(0.5μmol/L)可大部分取消茶黄素(20μmol/L)在模拟缺血液中的作用。结论茶黄素可通过抑制钠钙交换体转运和增强肌浆网钙泵活动,抑制缺血再灌注损伤中细胞[Ca2+]i的增加。

Study of theaflavin on reducing intracellular free calcium concentration in ventricular myocytes in rats with ischemia/reperfusion injury

Objective It is to explore the effects of theaflavin on intracellular calcium concentration i in rat ventricular myocytes and to discuss the possible mechanisms.Methods i in normal Tyrode's solution and simulated ischemia solution was detected by laser confocal microscopy and the result was represented by relative fluorescent intensity.Results Theaflavin(20 μmol/L) didn't affect the i of ventricular myocytes in normal Tyrode's solution,but reduced that in simulated ischemia solution.Pretreatment with the sodium-calcium exchanger inhibiter NiCl2(100 μmol/L) had similar effect as theaflavin(20 μmol/L)in simulated ischemia solution.Pretreatment with Thapsigargin(0.5 μmol/L),a specific SR i-pump ATPase inhibitor,mostly abolished the effects of theaflavin(20 μmol/L) in simulated ischemia solution.Conclusion Theaflavin may reduce the i in ventricular myocytes after ischemia/reperfusion injury through inhibiting sodium-calcium exchanger and improving the activity of SR [Ca2+]i-pump ATPase.