Linked Life Data

3123090

Source:http://linkedlifedata.com/resource/pubmed/id/3123090

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1988-3-10
pubmed:abstractText
We previously have shown that alpha-adrenergic stimulation of canine Purkinje fibers and rat ventricle decreases automaticity. Experiments on rat ventricular myocytes in tissue culture have suggested that the decrease in automaticity induced by alpha-adrenergic stimulation depends on the development of sympathetic innervation and the presence of a pertussis toxin-sensitive, 41-kDa guanosine triphosphate (GTP)-regulatory protein. In the present study, microelectrode and biochemical techniques were used to test the role of the pertussis toxin-sensitive protein and sympathetic innervation in modulating automaticity of adult canine Purkinje fibers. Fibers were incubated in Tyrode's solution alone or in Tyrode's solution plus pertussis toxin (0.1-0.5 microgram/ml) for 24 hours and were then superfused with phenylephrine. Phenylephrine in the 5 x 10(-9)-5 x 10(-8) M range induced a decrease in automaticity in 63% of the 16 fibers not treated with pertussis toxin and an increase in automaticity in 37%. The former group had a higher level of pertussis toxin-sensitive substrate by the [32P]nicotinamide adenine dinucleotide adenosine diphosphate (ADP)-ribosylation assay than the latter. In contrast, all fibers treated with pertussis toxin (0.5 microgram/ml) showed increased automaticity in response to phenylephrine and had no detectable pertussis toxin-sensitive substrate. Over the range of pertussis toxin concentrations studied, there was a smooth concentration-response relation between the substrate levels measured and the automatic response to phenylephrine. As ADP-ribosylatable substrate levels decreased, the percent of fibers showing an increase in automaticity increased.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0009-7330
pubmed:author
pubmed:issnType
Print
pubmed:volume
62
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
315-23
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Role of a pertussis toxin-sensitive protein in the modulation of canine Purkinje fiber automaticity.
pubmed:affiliation
Department of Pharmacology, Columbia University College of Physicians and Surgeons, New York, New York 10032.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't