Figure 3. Inhibitory effect of transporter blockers on the ACh release from myocytes.

Single channel recordings were made by cell-attached patch clamp in 1-day-old Xenopus myocytes. The patch was hyperpolarized +60 mV from rest. Note that the single channel currents were markedly enhanced when the patch pipette was filled with Ringer solution containing 1 μM neostigmine (A). Application of ACh transporter blockers vesamicol (B) or quinacrine (C) in the patch pipettes inhibited these currents. The current recordings were obtained from different patches of the same myocyte. Summary of the inhibitory effects of vesamicol and quinacrine is shown in D. Data are presented as means ± s.e.m (n). *P < 0.05 compared with respective control.