Figure 3
From: KATP channel subunits in rat dorsal root ganglia: alterations by painful axotomy
Preincubation with anti-SUR1 antibody abolishes the blocking effect of glybenclamide on single K ATP channel opening in excised membrane patches. Neurons preincubated with anti-SUR1 antibody (n = 5, D, E, F; purple) were compared to neurons preincubated in antibody-free solution (n = 7, A, B, C). Horizontal arrows indicate closed channel. A. Representative trace of KATP channel activity in patch excised from a neuron preincubated in antibody-free solution. In these neurons glybenclamide inhibited channel activity in a concentration-dependent fashion. B. Marked channel activity occurred upon excision of patch (vertical arrow in A) into an ATP-free solution. C. Glybenclamide 1000 nM blocked channel activity under control conditions. D. Representative trace of KATP channel activity in patch excised from a neuron preincubated with anti-SUR1 antibody. E. Excision of patch (vertical arrow in D) into an ATP-free external solution also activated channel. Cell-free patch exhibited similar KATP single channel activity as in controls (B). F. In contrast to neurons preincubated in antibody-free solution (C), glybenclamide 1000 nM failed to block channel activity after preincubation with anti-SUR1 antibody. G. Blocking effect of glybenclamide under control conditions is shown in the concentration-response curve (dotted-line; lower trace). Cumulative application of glybenclamide failed to block channel activity after preincubation with anti-SUR1 antibody, as indicated by the less steep concentration-response curve in G (solid line; upper trace). Means ± SD are shown. *:p < 0.05 versus glybenclamide 1 nM; §: p < 0.05 versus control. (Student's t tests were used for intergroup, and Bonferroni tests for intragroup post hoc comparisons).