Characterization of Multiple Ion Channels in Cultured Human Cardiac Fibroblasts

摘要: Background: Although fibroblast-to-myocyte electrical coupling is experimentally suggested, electrophysiology of cardiac fibroblasts not as well established contractile myocytes. The present study was therefore designed to characterize ion channels in cultured human fibroblasts. Methods and Findings: A whole-cell patch voltage clamp technique RT-PCR were employed determine expression their molecular identities. We found that multiple heterogeneously expressed These include a big conductance Ca 2+ -activated K + current (BKCa) most (88%) fibroblasts, delayed rectifier (IKDR) transient outward (Ito) small population (15 14%, respectively) cells, an inwardly-rectifying (IKir) 24% chloride (ICl) 7% cells under isotonic conditions. In addition, two types voltage-gated Na currents (INa) with distinct properties (61%) One slowly inactivated persistent component, sensitive tetrodotoxin (TTX) inhibition (INa.TTX ,I C50=7.8 nM), the other rapidly current, relatively resistant TTX (INa.TTXR C50=1.8 mM). revealed identities (mRNAs) these including KCa.1.1 (responsible for BKCa), Kv1.5, Kv1.6 IKDR), Kv4.2, Kv4.3 Ito), Kir2.1, Kir2.3 (for IKir), Clnc3 ICl), NaV1.2, NaV1.3, NaV1.6, NaV1.7 INa.TTX), NaV1.5 INa.TTXR). Conclusions: results provide first information are suggest potential contribution fibroblast-myocytes coupling.