ABSTRACT
AIM: To study the effects of 3-n-butylphthalide (NBP) on the TREK-1 channel expressed in Chinese hamster ovary (CHO) cells. METHODS: Whole-cell patch-clamp recording was used to record TREK-1 channel currents. The effects of varying doses of l-NBP on TREK-1 currents were also observed. Current-clamp recordings were performed to measure the resting membrane potential in TREK-1-transfected CHO (TREK-1/CHO) and wild-type CHO (Wt/CHO) cells. RESULTS: l-NBP (0.01-10 µmol/L) showed concentration-dependent inhibition on TREK-1 currents (IC(50)=0.06±0.03 µmol/L), with a maximum current reduction of 70% at a concentration of 10 µmol/L. l-NBP showed a more potent inhibition on TREK-1 current than d-NBP or dl-NBP. This effect was partially reversed upon washout and was not voltage-dependent. l-NBP 10 µmol/L elevated the membrane potential in TREK-1/CHO cells from -55.3 mV to -42.9 mV. However, it had no effect on the membrane potential of Wt/CHO cells. CONCLUSION: 1-NBP potently inhibited TREK-1 current and elevated the membrane potential, which may contribute to its neuroprotective activity.
