Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1999-6-29
pubmed:abstractText
The specific binding of [3H]QNB to rat duodenum smooth muscle membranes was a saturable process and Scatchard transformation of the saturation curves indicated a linear plot (nH = 1.017+/-0.071). The K(D) and Bmax values were 0.168+/-0.025 nM and 46.7+/-8.6 fmol/mg protein, respectively. Analyses of competition curves using pirenzepine and guanylpirenzepine indicated more than one class of binding site. A minor population of muscarinic binding sites showed high affinity (M1) for both pirenzepine (19.3+/-1.2%; pKi = 8.29+/-0.36) and guanylpirenzepine (29.4+/-2.0%; pKi = 7.28+/-0.11). The antagonistic affinity values of pirenzepine and guanylpirenzepine for the remaining low affinity binding sites, and that of methoctramine indicated the presence of both M2 and M3 subtypes. McN-A-343 produced relaxations in rat duodenum and inhibited twitch contractions of rabbit vas deferens induced by electrical stimulation in a concentration dependent manner. Carbachol (Cch) exerted concentration-dependent negative inotropic effect in rat atria and contractile effects in guinea-pig gallbladder and ileum longitudinal muscle-myenteric plexus preparation. Imperaline displaced the concentration-response curves to McN-A-343 and Cch to the right in parallel, without affecting the maximum responses in all tissues studied. The rank order of the pA2 values was rabbit vas deferens > rat atria > guinea-pig gallbladder = guinea-pig ileum > rat duodenum. The presynaptic muscarinic receptors at the rat duodenum and rabbit vas deferens were concluded to be of M1 and M4 subtypes, respectively.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0306-3623
pubmed:author
pubmed:issnType
Print
pubmed:volume
32
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
505-11
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Subtypes of muscarinic receptors in rat duodenum: a comparison with rabbit vas deferens, rat atria, guinea-pig ileum and gallbladder by using imperialine.
pubmed:affiliation
Department of Pharmacology, Istanbul University School of Pharmacy, Turkey.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't