Fig. 9. Comparison of the effects of short- and long-lasting K⁺-depolarizations on SNARE complexes. (A) SNAP-25-immunoreactive bands from membrane extracts of PC12 cells that were exposed to normal extracellular buffer (control, C) or to 57 mM K⁺ buffer for 5 or 10 minutes before membrane preparation. (B) Densitometric analysis of western blots with samples obtained after 5 or 10 minute depolarization with K⁺ (top graph, 57 mM K⁺; bottom graph, 110 mM K⁺). Averaged values (± s.d.) for the 100 kDa and 230 kDa bands from three to four experiments are shown as percentage of control.