Metoclopramide mimics a D-1 type of dopamine action in rabbit superior cervical ganglion.
Metoclopramide (MCP) in a sufficiently high concentration (100 microM) induced a large and persisting potentiation of slow-excitatory postsynaptic potentials (s-epsp) and slow-inhibitory postsynaptic potentials (s-epsp) but depressed in fast epsp. This modulatory action of metoclopramide was markedly suppressed by (+)-butaclamol (7 microM) and, to a lesser extent, by spiroperidol (2.5-4 microM). Metoclopramide also possessed weak anti-acetylcholinesterase activity(I50% = 245 microM; measured by Dr N. Inestrosa), but this was shown not to account for the potentiating actions of metoclopramide. Thus, although metoclopramide is a D-2 antagonist, it appears to mimic the D-1 action of dopamine in modulating the slow psps.
D000200:Action Potentials / Q000187:drug effects*; D000818:Animals; D004298:Dopamine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005728:Ganglia, Sympathetic / Q000502:physiology*; D066298:In Vitro Techniques; D008787:Metoclopramide / Q000494:pharmacology*; D011817:Rabbits; D013469:Sulpiride / Q000494:pharmacology; D013570:Synaptic Membranes / Q000502:physiology
D013469:Sulpiride; D008787:Metoclopramide; D004298:Dopamine