Effects of bradykinin on ion conductances in NG108-15 neuroblastoma x glioma hybrid cells recorded with patch-clamp electrodes.

Under whole-cell recording, bradykinin (BK) produced an initial outward membrane current followed by an inward current in voltage-clamped NG108-15 cells. The initial outward current was associated with a rise in intracellular Ca2+ and was accompanied by the opening of Ca(2+)-dependent K(+)-channels recorded with a cell-attached patch electrode. This current was inhibited by intracellular Mg2+. The inward current was associated with inhibition of the voltage-dependent K(+)-current IK(M). These effects accord with those previously observed in microelectrode-impaled cells, with the difference that BK produced much more pronounced and long-lasting desensitization in the patch-clamped cells.