目的：建立爪蟾卵母细胞表达的HCN通道的细胞模型，研究其生物学特性，并为药物评价建立细胞模型。方法：将HCN1及HCN2的互补DNA（cDNA）体外转录为互补RNA（cRNA）后，分别注射至去除滤泡膜的非洲爪蟾卵母细胞中，表达1~3 d后采用双电极电压钳技术记录其电流。结果：在爪蟾卵母细胞表达的HCN1及HCN2通道的同聚体细胞模型上，记录到了超极化激活的内向阳离子电流，此电流被称为Ih电流，可被HCN通道特异性阻断剂CsCl所阻断；在1 mmol/L的CsCl作用下，HCN通道产生的电流幅度显著减小，在-140 mV水平，HCN1电流幅度减少率为83.4%±9.5%（n=5，P<0.001），HCN2产生的电流幅度减少率为99.7%±0.6%（n=4，P<0.001）。结论：建立了表达HCN1及HCN2通道的爪蟾卵母细胞模型，为研究HCN通道生物学特点以及药物评价奠定了基础。%Objective: To study biological characteristics of HCN channel and evaluate effect of compound on HCN channel, we establish a cell model predominantly expressing HCN channel in oocytes. Methods: The cDNAs of HCN1 and HCN2 were transcribed into cRNA in vitro and injected into Xenopus oocyte. The electrophysiologi⁃cal experiment was performed on the injected cells after 48~72 hour culture. Results: Hyperpolarization-activated inner cation current can be recorded in Xenopus oocytes, which was inhibited by use of CsCl, a specific blocker of HCN channel. In the level of -140 mV, the amplitude of HCN1 was inhibited 83.4%±9.5% compared with con⁃trol(n=5,P<0.001), and the inhibition rate of HCN2 channel current amplitude reached 99.7%± 0.6%(n=4,P<0.001). Conclusion: The functional express of HCN1 and HCN2 was confirmed by the electrophysiological experi⁃ment and the cell model should be valuable for further study on the compound evalution.
展开▼
