PROPOFOL BLOCKS VOLTAGE-GATED POTASSIUM CHANNELS IN HUMAN T-LYMPHOCYTES

The effect of propofol (PR) on voltage-gated potassium channels (K-V) in human T lymphocytes (TL) was studied using the patch-clamp techniqu e in the whole-cell configuration. PR was found to reversibly block th e K-V channels in a dose-dependent manner with a half-blocking concent ration of approximately 40 mu M. The decrease in the peak current caus ed by PR was voltage-independent The activation time constant of the w hole cell potassium currents remained unaffected upon PR treatment, wh ereas both the rate and extent of the inactivation process were increa sed, indicating the ''open channel block'' mechanism. The PR half-bloc king concentration was of the same order of magnitude as PR blood conc entrations employed in anesthesia. Taking into account the extensive u se of PR and the important role of K-V channels in human TL, these res ults suggest a need for investigations into the effect of PR on TL cel l-function regulation.