Open AccessJournal Article
Cholinergic potentiation by ouabain in the contraction of guinea-pig vas deferens through pre- and post-synaptic mechanism.
T Katsuragi,T Furukawa +1 more
TLDR
The results suggest that pilocarpine and arecoline act as ACh-releaser in this tissue and that the ouabain-induced cholinergic potentiation may be attributable to a dual mechanism, facilitation of ACh release at presynaptic site and alteration of the membrane excitability at postsynaptic site.Abstract:
In the guinea-pig vas deferens, the contractions induced by pilocarpine and arecoline, unlike ACh, were markedly reduced by treatment with procaine (10(-6) g/ml) or hemicholinium (5 x 10(-4) g/ml). These reductions by hemicholinium were completely recovered after exposure to choline. The contractile responses to these three agonists were eliminated by atropine (3 x 10(-8) g/ml) but enhanced by neostigmine (3 x 10(-8) g/ml), though these were not affected at all by tetrodotoxin (3 x 10(-8) g/ml) or hexamethonium (10(-5) g/ml). The contractile responses to ACh, pilocarpine and arecoline were potentiated by ouabain (10(-6) g/ml). These potentiations were more marked in pilocarpine and arecoline than those in ACh. The potentiation in response to arecoline was maximal after incubation with ouabain for 5 min but that to ACh for 45 min. The results suggest that pilocarpine and arecoline act as ACh-releaser in this tissue and that the ouabain-induced cholinergic potentiation may be attributable to a dual mechanism, facilitation of ACh release at presynaptic site and alteration of the membrane excitability at postsynaptic site.read more
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Journal ArticleDOI
Antinociceptive synergistic interaction between clonidine and ouabain on thermal nociceptive tests in the rat.
TL;DR: The results suggest that the synergistic interaction of ouabain and clonidine were probably mediated, at least in part, via an enhancement of cholinergic transmission in the spinal nociceptive processing system.
Journal ArticleDOI
Contractile responses of the guinea-pig vas deferens to the combination of vanadium ions with ouabain.
TL;DR: The hypothesis that vanadium compounds and ouabain have a similar mechanism of action for the contraction induced in guinea-pig vas deferens is not supported.
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