Linked Life Data

8708987

Source:http://linkedlifedata.com/resource/pubmed/id/8708987

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
1996-9-11
pubmed:abstractText
The pre- and postjunctional activities of a number of diadenosine polyphosphates were examined in the guinea-pig isolated vas deferens at the level of the membrane potential, using a modified sucrose-gap technique. P1,P3-Di(adenosine 5')triphosphate (Ap3A), P1,P4-di(adenosine 5')tetraphosphate (Ap4A) and P1,P5-di(adenosine 5')pentaphosphate (Ap5A) all caused concentration-dependent depolarization of the smooth muscle membrane. The potency order was: Ap5A > Ap4A > or = Ap3A. P1,P2-Di(adenosine 5')pyrophosphate (Ap2A) did not evoke depolarization even at the highest concentration tested (1 mM). All the dinucleotides caused a reduction in the amplitude of evoked excitatory junction potentials (e.j.ps). The potency order was: Ap5A = Ap4A > Ap3A > Ap2A. The depolarizations evoked by the dinucleotides were markedly reduced by the selective P2X-purinoceptor antagonist, pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS, 10 microM), as was the amplitude of the fully facilitated e.j.p. The inhibition of the e.j.p. evoked by Ap3A and Ap2A was reduced by the P1-purinoceptor antagonist, 8-p-sulphophenyltheophylline (8-pSPT, 50 microM), but that evoked by Ap5A and Ap4A was not. Thus, Ap3A, Ap4A and Ap5A evoke depolarization of the guinea-pig vas deferens via P2X-purinoceptors, and additionally Ap2A and Ap3A exert a prejunctional effect via P1-purinoceptors. The prejunctional activity of Ap4A and Ap5A is mediated via an undefined purinoceptor, which is neither P1 nor P2X.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0022-3573
pubmed:author
pubmed:issnType
Print
pubmed:volume
47
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
926-31
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Pre- and postjunctional effects of diadenosine polyphosphates in the guinea-pig vas deferens.
pubmed:affiliation
Department of Anatomy and Developmental Biology, University College London, UK.
pubmed:publicationType
Journal Article, In Vitro