Linked Life Data

8720590

Source:http://linkedlifedata.com/resource/pubmed/id/8720590

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2-3
pubmed:dateCreated
1996-9-26
pubmed:abstractText
Intracellular accumulation of Mn2+ augmented the contractions induced by norepinephrine and acetylcholine in the guinea pig isolated vas deferens. Contractions repeatedly induced by norepinephrine, acetylcholine, or a high concentration of K+ decreased depending on the incubation time in Ca(2+)-free medium. The rate of decrease of all contractions was delayed by intracellularly accumulated manganese. In the Mn(2+)-loaded preparations, the tonic components of the contractions induced by norepinephrine and acetylcholine, but not K+, were highly resistant to extracellular Ca2+ elimination. Ryanodine abolished the initial phasic component but did not affect the tonic component of norepinephrine- and acetylcholine-contractions in Mn(2+)-loaded preparations in Ca(2+)-free medium. In Ca(2+)-depleted preparations, the tonic contraction induced by norepinephrine was restored after the Mn(2+)-loading procedure, and the magnitude of this tonic contraction was comparable to the tonic component of the norepinephrine contraction in the normal medium before Mn2+ loading. The tonic contraction was reproducible in medium without either Mn2+ or Ca2+. These results suggested that intracellular Mn2+ can support norepinephrine-induced tonic contractions. In the Ca(2+)-depleted Mn(2+)-loaded preparations, K+ also induced a tonic contraction in the presence of extracellular Mn2+. However, this contraction was much smaller than that induced by norepinephrine. These results suggested that intracellular Mn2+ augmented contractions not only via an increase in intracellular Ca2+ availability but also via the direct action of Mn2+ on contractile mechanisms, and that this action is highly specific for developing and/or maintaining tonic contractions mediated by receptor activation in the guinea pig isolated vas deferens.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0014-2999
pubmed:author
pubmed:issnType
Print
pubmed:day
11
pubmed:volume
295
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
235-41
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
The specific effect of Mn2+ on the tonic components of receptor-mediated contractions in isolated vas deferens of the guinea pig.
pubmed:affiliation
Department of Pharmacology, Kanazawa University, Japan.
pubmed:publicationType
Journal Article