Dopamine decreases quantal output in mouse muscles.
Dopamine was found to reduce the quantal content of end-plate potentials in cut-fiber preparations of mouse diaphragm but not in Mg2+-blocked preparations. Possible mechanisms for this effect include reduction of the presynaptic store of acetylcholine available for release, or blockade by dopamine of a positive feedback on acetylcholine release, possibly mediated by muscarinic receptors on nerve terminals.
D000109:Acetylcholine / Q000378:metabolism; D000818:Animals; D003964:Diaphragm; D004298:Dopamine / Q000494:pharmacology*; D004594:Electrophysiology; D051379:Mice; D008815:Mice, Inbred Strains; D009045:Motor Endplate / Q000187:drug effects; D009132:Muscles / Q000187:drug effects / Q000378:metabolism*; D009469:Neuromuscular Junction / Q000378:metabolism
D000109:Acetylcholine; D004298:Dopamine