Linked Life Data

1650825

Source:http://linkedlifedata.com/resource/pubmed/id/1650825

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1991-9-11
pubmed:abstractText
The smooth muscle of guinea pig uterus is contracted by adenosine in a manner consistent with the presence of a purine nucleoside receptor of the P1-A1 subtype that is uncoupled from adenylate cyclase. Here we investigate the signal transduction mechanism responsible for adenosine's ability to contract uterine smooth muscle. The A1 adenosine receptor antagonist [3H]-8-cyclopentyl-1.3- dipropyl xanthine ([3H]CPX) bound reversibly to a large number (172 +/- 25 fmol/mg of protein) of receptors in myometrial smooth muscle membranes from estrogen-primed virgin guinea pigs with an affinity (KD = 1.77 +/- 0.21 nM) similar to that expected of [3H]CPX binding to both central and peripheral A1 receptors. In the absence of the stable GTP analog, guanosine-5'-O-[3-thiotriphosphate], agonist competition of [3H]CPX binding resulted in a biphasic curve that was best fit assuming the presence of equal populations of two affinity states of the receptor. Addition of guanosine-5'-O-[3-thiotriphosphate] (10 microM) resulted in a monophasic competition curve of low affinity suggesting coupling of this A1 receptor to effector via a GTP binding protein. In [3H]myo-inositol labeled strips of myometrial smooth muscle, the adenosine agonist R-phenylisopropyl adenosine (R-PIA) stimulated the rapid formation of inositol-1,4,5-trisphosphate (InsP3) that was antagonized by addition of the nucleoside receptor antagonist 8-sulfophenyl theophylline. Prostaglandin stimulation of myometrial strips also increased InsP3 formation. Furthermore, R-PIA stimulated the disappearance of inositol phosphate (InsP) in a fashion consistent with agonist stimulation of an inositol phosphatase activity.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0022-3565
pubmed:author
pubmed:issnType
Print
pubmed:volume
258
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
429-37
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Action of adenosine in estrogen-primed nonpregnant guinea pig myometrium: characterization of the smooth muscle receptor and coupling to phosphoinositide metabolism.
pubmed:affiliation
Department of Pharmacology, University of Nevada School of Medicine, Reno.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.