Linked Life Data

2861571

Source:http://linkedlifedata.com/resource/pubmed/id/2861571

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1985-8-13
pubmed:abstractText
The sensitivity to sympathomimetic amines of isolated atria removed from sham-injected and 6-hydroxydopamine-treated (6-OHDA) guinea-pigs was examined in the presence of an extraneuronal uptake blocker and an alpha-adrenoceptor antagonist. Three weeks of pretreatment with 6-OHDA resulted in leftwards shifts of the dose-response curves for the positive chronotropic and inotropic responses of right and left atria to isoprenaline. The responses to the partial agonist salbutamol were also potentiated after 6-OHDA pretreatment, revealed as an increase in the maximum response relative to isoprenaline. The supersensitivity was post-synaptic in origin and independent of changes in disposition or metabolism, since it was observed with agonists immune to neuronal uptake and O-methylation, and in the presence of extraneuronal uptake inhibition by metanephrine. It was also specific for the beta-adrenoceptor, no supersensitivity to histamine being found. In the right atria, the supersensitivity was partially masked by an opposing depressant effect after 6-OHDA pretreatment which was observed with histamine. Dissociation constants (KA) for the left atrial inotropic responses to orciprenaline were determined by use of the antagonist Ro 03-7894. Atria from 6-OHDA-pretreated animals were supersensitive to orciprenaline, but the KA value did not differ from that after sham injection. It could therefore be concluded that the increase in sensitivity was not due to an increase in affinity for the beta-adrenoceptor.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0028-1298
pubmed:author
pubmed:issnType
Print
pubmed:volume
329
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
162-6
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1985
pubmed:articleTitle
Cardiac postjunctional supersensitivity to beta-agonists after chronic chemical sympathectomy with 6-hydroxydopamine.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't