Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1991-10-3
pubmed:abstractText
Pilocarpine, a partial agonist, activates propylbenzilylcholine mustard (PrBCM)-sensitive cholinoceptors in the guinea pig ileal longitudinal muscle, while carbachol, a full agonist, predominantly activates PrBCM-resistant ones. Carbachol behaves as a partial agonist in the preparation treated with phenoxybenzamine and mainly activates PrBCM-sensitive cholinoceptors, as phenoxybenzamine preferably blocks PrBCM-resistant ones. The receptor occupancy-response curve for carbachol became a rectangular hyperbola, while pilocarpine showed a linear relation. After occlusion of cholinoceptors with phenoxybenzamine, carbachol showed a linear receptor occupancy-response relation, suggesting that its contraction mechanisms after occlusion of cholinoceptors resemble those for pilocarpine. Both the agonists induced an increase in cytosolic Ca2+ concentration [( Ca2+]i) and tension development in a concentration-dependent manner under the conditions used herein. The slopes of the regression lines between [Ca2+]i and tension development for pilocarpine in the untreated preparation and for carbachol in the preparation treated with phenoxybenzamine were significantly steeper than that for carbachol in the untreated preparation, suggesting that carbachol in the phenoxybenzamine-treated preparation and pilocarpine induced a greater tension for a given increase in low [Ca2+]i than did carbachol. Thus an activation of PrBCM-sensitive cholinoceptors might enhance the Ca2+-sensitivity of the contractile elements.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0021-5198
pubmed:author
pubmed:issnType
Print
pubmed:volume
56
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
151-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Propylbenzilycholine mustard (PrBCM)-sensitive cholinoceptors and contractile response to partial agonist in guinea pig ileal muscle.
pubmed:affiliation
Department of Chemical Pharmacology, Toho University School of Pharmaceutical Sciences, Chiba, Japan.
pubmed:publicationType
Journal Article, In Vitro