Cyclic AMP synchronizes evoked quantal release at frog neuromuscular junctions
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Updated: Oct 10, 2026

Loading a Calcium Dye into Frog Nerve Endings Through the Nerve Stump: Calcium Transient Registration in the Frog Neuromuscular Junction
Published on: July 8, 2017
E Bukcharaeva1, D Samigullin, E E Nikolsky
1Kazan Medical University, Russia.
Abstract:
At frog neuromuscular junction, noradrenaline (NA) shortens the release period for evoked quantal release acting on a beta1 receptor. To test the hypothesis that this action of NA is mediated by cAMP, we measured the latencies of focally recorded uni-quantal endplate currents (EPCs) after application of dibutyryl-cAMP (db-cAMP) and adenylyl cyclase activator, forskolin. The interval between the time when responses with minimal delay appeared and the point at which 90% of all latencies had occurred (P90 parameter) was shortened in the presence of both 1 x 10(-6) mol/l db-cAMP and 1 x 10(-6) mol/l forskolin by about 30%. The cAMP-induced shortening is equal to that found after application of NA and effects of both drugs are not additive.
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