Macrophages express Kv1.3 and Kv1.5. Cells were held at −80 mV, and pulse potentials were applied as indicated. (A) Representative traces of delayed rectifier K+ currents. (B) Steady-state activation curve of the outward current. Conductance was plotted against test potentials. (C) mRNA expression of Kv1.3 and Kv1.5 in Raw 264.7 cells. Mouse brain and heart RNA were used as positive controls for Kv1.3 and Kv1.5, respectively. PCR reactions were performed in the presence (+) or absence (−) of the retrotranscriptase reaction. (D) Kv1.3 and Kv1.5 protein expression in Raw macrophages. Jurkat T lymphocytes and L6E9 skeletal muscle myoblasts were used as positive controls for Kv1.3 and Kv1.5, respectively. (E) Immunocytochemical electron microscopic detection of Kv1.3 and Kv1.5 proteins. Arrows show specific channel protein localization. Black arrow, Kv1.3; white arrow, Kv1.5; bar, 0.20 µm.
