关键词: 血清素;心肌/细胞学;钙;显微镜检查，共焦

    摘 要:目的 观察5-羟色胺(5-HT)对新生大鼠心肌细胞内游离Ca2+ 浓度的影响，并探讨其作用机制. 方法 培养SD大鼠(1～3d)心肌细胞，应用特异性Ca2+ 荧光指示剂Fluo-3/AM负载细胞，激光共聚焦显微镜检测游离Ca 2+ 浓度. 结果 5-HT在10-6 ，10-5 ，10

    -4 mol L-1 时均可升高心肌游离Ca2+ 浓度，且随剂量增加而加强;二氢吡啶类钙通道阻断剂lacidipine可部分拮抗5-HT的作用;心肌肌浆网内钙释放通道ryanodine受体调节剂ryanodine，在10-5 mol L-1 时也可部分拮抗5-HT的作用;用EGTA络合细胞外液中游离Ca2+ ，5-HT升高心肌游离Ca2+ 作用明显减弱;此外，5-HT二型受体(5-HT2 R)阻断剂赛庚定具有显著抑制5-HT升高心肌游离Ca2+ 的作用. 结论 5-HT具有升高心肌游离Ca2+ 的作用，其机制可能与细胞外Ca 2+ 经5-HT2 R或二氢吡啶类钙通道进入细胞以及肌浆网内钙释放有关.

    Effects of5┐hydroxytryptamine on intracellular free Ca2+ of myocardium

    ZHAO Ming-Gao ，WANG Jian-Bo ，MEI Qi-Bing ，CHEN Dan ，ZHAO De-Hua ，WANG Chun-Mei ，ZHANG Yan-Feng

    1 Department of Pharmacology，2 Center Laboratory，Faculty of Preclinical Medicine，Fourth Military Medical University，Xi'an710033，China

    Keywords:sevotonin;myocardium/cytology;calcium;mi-croscopy，confocal

    Abstract:AIM To observe the effects of5-hydrox-ytryptamine(5-HT)on intracellular free Ca2+ of neonatal rat myocardium and to investigate its mechanism.METHODS Neonatal rat myocardium was cultured to measure intracellu-lar free Ca2+ concentration by calcium fluorescent probe Fluo-3/AM and laser confocal microscope.RESULTS 5-HT was found to increase intracellular free Ca2+ concentration in a dose-dependent manner.The addition of lacidipine ......