自发钙火花与诱发钙火花的形态特征比较  

Morphometric Difference Between Spontaneous Ca^(2+) Sparks and Evoked Ca^(2+) Sparks

作　　者：沈建新[1,2] 王世强[3] 程和平[3] 

机构地区：[1]汕头大学医学院生理学教研室 [2]西安交通大学医学院生理学教研室,陕西西安710061 [3]北京大学生命科学学院膜与膜生物工程国家实验室

出　　处：《中山大学学报（医学科学版）》2004年第5期390-394,共5页Journal of Sun Yat-Sen University:Medical Sciences

基　　金：国家重大基础研究发展基金资助项目(G2000057002);西安交通大学重点基金资助项目(X160;082003);广东省卫生厅"五个一"工程重点基金资助项目(413626);汕头市"四一一五"工程重点项目(961224);汕头大学研究与发展基金资助项目(L00015)

摘　　要：【目的】钙火花是胞内基本的钙释放事件,既可以在静息的状态下随机产生,也可以被通过L-型钙通道内流的少量钙离子诱发产生。对钙火花特征和产生机理的研究极大地深化了我们对兴奋-收缩耦联过程的理解。本研究的目的旨在比较同一条件下自发钙火花和由loose-patch方法诱发的可以准确测量的钙火花之间在形态特征上的异同,以加深我们对钙火花的认识。【方法】激光共聚焦显微镜线扫描成像技术可记录到加载有荧光染料fluo-4的成年大鼠心肌细胞中随机产生的自发钙火花;而非紧密封接膜片钳技术与激光共聚焦显微镜线扫描成像相结合的方法(loose-patch方法)可准确记录诱发钙火花。【结果】总体上,在相同条件下共聚焦显微镜线扫描方式记录到的自发钙火花与诱发钙火花的基本特征相似;但诱发钙火花的幅度高于自发钙火花的幅度(1.00±0.05)vs(0.80±0.06),P<0.05),而空间扩散范围则小于自发钙火花的空间范围(1.35±0.05)μmvs(1.94±0.08)μm,P<0.05)。【结论】自发钙火花和诱发钙火花因其记录方法不同而在形态特征上有不同表现,这对于正确分析钙火花数据和准确理解胞内钙信号的实质有重要意义。Ca 2+ sparks are considered to be the eleme ntary events of intracellular Ca 2+ release.Ca 2+ Sparks not only can occur spontaneou sly and stochastically in quiescent cardiac myocytes,but also can be evoked by Ca 2+ influx through L-type Ca 2+ channels locally.The investigation of Ca 2+ sparks enhanced our understanding a bout excitation-contraction coupl ing greatly.In this study,to deepen our knowledge about Ca 2+ sparks,we would like to compare the morphometrics between spontaneous Ca2+ sparks and evoked Ca2+ sparks.The latter were activated by loose-patch method and could be dete cted exactly.In single quiescent cardiac myocyte s loaded with fluo-4,spontaneous Ca2+ sparks could be detected by confocal laser scanning microscopic line-scanning imaging.And evoked Ca2+ sparks could be activated by loose-s eal patch-clamp and detected exactly by confocal laser s canning microscopic line-scanning imaging,which is so called the loose-patch method.In general,under the same condition s,spontaneous Ca 2+ sparks and evoked Ca 2+ sparks were analogous in morphometr ics,except that the evoked ones were higher inamplitude [(1.00±0.05) vs (0.80±0.06),P<0.05] and narrower in width [1.35±0.05)] μm vs (1.94±0.08) μm, P<0.05 than the spontaneous ones.[Conclusion]There are some differ-ence in morphometrics between spont aneous Ca 2+ sparks and evoked Ca 2+ sparks because of the differ-ent imaging methods.This would be im portant for data analysis of Ca 2+ sparks and understanding the essential of intracellular signali ng.

关 键 词：诱发 发钙 钙火花 激光共聚焦显微镜 成年大鼠 心肌细胞 膜片钳技术 钙释放 L-型钙通道 钙信号 

分 类 号：R363[医药卫生—病理学] Q257[医药卫生—基础医学]