Ion channels are important for the functions of excitable and non-excitable cells. Using the whole-cell patch clamp technique, we analyzed the electrophysiological and pharmacological properties of voltage-gated potassium channels in primary rat peritoneal macrophages. With intracellular solution contained K(+) as the main charge carrier, all cells showed outward currents in response to membrane depolarization. The currents can be inhibited by TEA (10 mM), a non-selective blocker for voltage-gated K(+) channels, and attenuated when intracellular K(+) was substituted with Cs(+). Changing holding potential from -80 to -30 mV or -10 mV also inhibited the outward currents. In contrast, increasing the concentration of ATP in the intracellular solution decreased the amplitude of the outward currents. Thus, rat peritoneal macrophages express several types of functional voltage-gated K(+) channels.
Keywords: ATP; Patch-clamp; TEA; peritoneal macrophage; potassium channel.