6533b822fe1ef96bd127d88e

RESEARCH PRODUCT

Choline inhibits acetylcholine release via presynaptic muscarine receptors

Heinz KilbingerR. Kruel

subject

medicine.medical_specialtyGuinea PigsScopolamineMyenteric PlexusIn Vitro TechniquesTritiumInhibitory postsynaptic potentialCholinechemistry.chemical_compoundHemicholinium-3Internal medicinemedicineAnimalsCholineReceptors CholinergicMyenteric plexusPharmacologyMuscarineHemicholinium 3General MedicineReceptors MuscarinicCholine acetyltransferaseAcetylcholineEndocrinologychemistryCholinergicNeuroscienceAcetylcholineMuscle Contractionmedicine.drug

description

The effect of exogenous choline on the outflow of 3H-acetylcholine evoked by field stimulation was studied on the myenteric plexus-longitudinal muscle preparation of the guinea pig. Choline at concentrations of 100 microM and higher depressed the evoked outflow of 3H-acetylcholine in a concentration-dependent manner. The EC50 for the inhibitory action was 300 microM. Scopolamine (10 nM) antagonized the effect of choline which indicates that the inhibition of 3H-acetylcholine outflow is mediated by muscarine receptors. The findings imply that choline at high concentrations does not improve cholinergic synaptic neurotransmission in tissues that are endowed with presynaptic muscarine receptors (e.g. myenteric and central cholinergic neurones). Furthermore, it is suggested that the increase in tissue acetylcholine content that has been observed after choline administration is probably due to the depression of acetylcholine release.

yearjournalcountryeditionlanguage
1981-04-01Naunyn-Schmiedeberg's Archives of Pharmacology
https://doi.org/10.1007/bf00505306