FIGURE 2.
Leukotriene B4, but not other leukotrienes of the LT4 family, activates recombinant (cbv1-β1) BK channel. A, single-channel recordings from I/O patches excised from X. laevis oocytes expressing cbv1-β1 channel complexes. Current records depict cbv1-β1 channel activity before, during, and after 1 nm LTB4 application. Vm = −20 mV; [Ca2+]i = 10 μm. Here and in all other figures, channel openings are shown as downward deflections; arrows indicate the baseline (all channels closed); control and washout correspond to bath solution. Unless stated otherwise, all data were obtained using the I/O patch configuration. B, concentration response curve for LTB4. Each point represents the average of no fewer than three patches, each patch obtained from a different oocyte. C, averaged increase in cbv1-β1 channel activity (NPo) by different leukotrienes applied at 1 nm. D, averaged increase in cbv1-β1 channel NPo by different leukotrienes applied at 1 μm. E, averaged increase in cbv1-β1 channel NPo by different leukotrienes applied at 1 μm to the extracellular side of the patch in the O/O patch configuration. In C–E, an asterisk indicates difference from control (p < 0.05). Error bars, S.E.