Voltage-activated Cl- Conductance in Cultured Human Melanocytes

Abstract

Using the whole-ell patch-clamp technique we recorded Cl^(-) currents in cultured human melanocytes. With high symmetrical Cl^(-) solutions melanocytes expressed time-dependent Cl^(-) currents that did not run down for approximately 30 min. The currents showed voltage-dependent activation and reached a steady-state at about 500 msec during hyperpotarizing pulses. Current vs. voltage relation indicates that the current was activated by more hyperpotarizing voltage Steps, showing inward rectification. Based on conductance vs. voltage relation the half activation voltage of the current was determined tobe -60 mV. When tail current amplitudes were plotted as a function of test pulses, tail current reversed at -10 mV, dose to ECI of 0 mV in this condition, indicating that the observed current was specific Cl^(-) current.