应用显微荧光测钙技术研究乙酰胆碱对豚鼠耳蜗外毛细胞内游离钙的影响

Study on changing of intracellular free Ca^(2+) induced by ACh in outer hair cells of guinea pig using Fura-2 microfluorimetry

介绍了应用显微荧光测钙技术研究豚鼠耳蜗外毛细胞（OHC）内游离钙浓度（[Ca^(2+)]i）变化的方法。该技术以钙敏感染料Fura－2作为胞内Ca^(2+)的指示剂，装载进入细胞后，与胞内游离Ca^(2+)结合，在特定波长光的激发下可发出荧光，由此可推算[Ca^(2+)]i的变化。结果发现乙酰胆碱（ACh）在含钙的细胞外液中可引起［Ca^(2+)］i升高。对显微荧光测钙技术在研究耳蜗毛细胞中的应用以及ACh引起［Ca^(2+)］i升高的机制进行了讨论。

The method of studying intracellular free Ca^(2+) ([Ca^(2+)]i) in outer hair cells (OHC)of guinea pig using digital imaging microscopy and Ca^(2+)- sensitive fluorescent dye Fura-2 was introduced. [Ca^(2+]i can be calculated from fluorescence intensity ratios with excitation lights of twodifferent wave-lengths, using Fura-2 loaded in OHC. The data showed that acetylcholine (ACh)can induce [Ca^(2+)]i elevation of OHC in the solution with calcium. Mechanism of ACh inducing[Ca~(2+]i elevation and application of calcium imaging microfluorometry for studying cochlea hair cellwere discussed.