Effect of dl-praeruptorin A on ATP sensitive potassium channels in human cortical neurons

To investigate the effect of dl-praeruptorin A (Pd-Ia) on ATP sensitive potassium channels (KATP channel) in human cortical neurons. Using standard whole cell recording method. Cell membranes were held at -40 mV, commanding potential was -30 to +100 mV and duration was 600 ms. Pd-Ia activated KATP channels in human cortical neurons in a concentration-dependent manner. After consecutive perfusion with external solution containing Pd-Ia 0.001, 0.01, 0.1, and 1 micromol/L, currents increased from control (0.9 +/- 0.4) nA to (1.0 +/- 0.4) nA, (1.1 +/- 0.4) nA, (1.2 +/- 0.4) nA, and (1.3 +/- 0.4) nA (P < 0.05 or P < 0.01, n = 5) respectively. Then the current decreased to (0.90 +/- 0.37) nA (P < 0.01, n = 5) after washout with glibenclamide (10 micromol/L). The increscent part of the currents could nearly be inhibited by specific KATP channel inhibitor. Pd-Ia could open KATP channel and it is a kind of potassium channel opener