Propofol blocks voltage-gated potassium channels in human T lymphocytes

The effect of propofol (PR) on voltage-gated potassium channels (KV) in human T lymphocytes (TL) was studied using the patch-clamp technique in the whole-cell configuration. PR was found to reversibly block the KV channels in a dose-dependent manner with a half-blocking concentration of approximately 40 microM. The decrease in the peak current caused by PR was voltage-independent. The activation time constant of the whole-cell potassium currents remained unaffected upon PR treatment, whereas both the rate and extent of the inactivation process were increased, indicating the "open channel block" mechanism. The PR half-blocking concentration was of the same order of magnitude as PR blood concentrations employed in anesthesia. Taking into account the extensive use of PR and the important role of KV channels in human TL, these results suggest a need for investigations into the effect of PR on TL cell-function regulation.