The pre-synaptic blocker toosendanin does not inhibit secretion in exocrine cells

Figure 1 Concentration dependence of cholecystokinin (CCK)-stimulated amylase secretion. Note that maximum secretion was achieved at 100 pM of CCK. n = 6

Figure 2 Effect of toosendanin (TSN) on CCK-stimulated amylase secretion. TSN was added to the pancreatic acini 10 min before stimulation with CCK which was maintained for another 30 min. A. TSN 87 μM, n = 6. B. TSN 870 μM, n = 4. Note that, for clarity, the same CCK dose-response curve (n = 6) was drawn both in A and B.

Figure 3 Effect of toosendanin on 5 pM CCK-induced calcium oscillations. CCK and TSN were added as indicated by the horizontal bars. A. TSN 8.7 μM, n = 4. B. TSN 87 μM, n = 7. C. TSN 870 μM, n = 8.

Figure 4 Effect of FK480 on CCK-induced calcium oscillations. 5 pM of CCK and 10 nM of FK480 were added as indicated by the horizontal bars. n = 5.