维拉帕米对海洛因诱发的乳鼠心肌细胞钙活动异常的作用

Antagonistic Effects of Verapamil on [Ca^(2+)]i Hyperactivated by Heroin in Newborn Rat Cardiomyocytes

【目的】研究海洛因对乳鼠心肌细胞钙活动的影响以及维拉帕米对海洛因作用下的乳鼠心肌细胞钙活动的影响作用。【方法】使用体外培养5 d的SD乳鼠心肌细胞,标记细胞内游离钙,应用激光共聚焦显微镜下检测细胞内荧光强度变化可指示细胞内游离Ca2+浓度([Ca2+]i)变化;并应用碘化丙啶进行活性细胞检测。【结果】0.01 mol/L海洛因可增加培养心肌细胞平均细胞内钙浓度和钙瞬变的幅度,对自发性收缩节律无明显影响;20μmol/L维拉帕米可明显抑制海洛因诱导的钙超载,并可降低收缩节律,减少细胞死亡。【结论】海洛因可导致心肌细胞钙超载和钙活动异常,导致细胞死亡,维拉帕米可抑制细胞内钙活动,保护心肌细胞。

【Objective】 To study the intracellular calcium concentration（[Ca2＋]i） mobilized by heroin and the possible remedy by verapamil in newborn rat cardiomyocytes.【Methods】 [Ca2＋]i was measured with fluorescent intensity（FI） by confocal microscope in single cultured 5d newborn rat cardiomyocytes loaded with Fluo 3-AM;propidium iodide was added to identify dead cells.【Results】 The average fluorescence intensity and amplitude of calcium transients over 80 s recording period were statistically up-regulated by 0.01 mol/L heroin（P 0.01）.The effects were reversed by the addition of 20 μmol/L verapamil.Post-treatments with verapamil partly rescued the cell death induced by continuous administration of heroin.【Conclusion】 Verapamil possesses the antagonistic effects and protective effects on the increased level and vibration of [Ca2＋]i induced by heroin in cultured cardiomyocytes.