Linked Life Data

9234653

Source:http://linkedlifedata.com/resource/pubmed/id/9234653

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1997-8-29
pubmed:abstractText
Although it is essential to cardiac conduction, little is known about the biochemistry underlying postreceptor adrenergic, cholinergic and purinergic processes in the AV node. To study these mechanisms, we adapted a new and highly sensitive fluorometric assay for cyclic adenosine monophosphate (AMP) to characterize regional adenylylcyclase activity (cyclic AMP production in pmol/min/mg of protein) in membrane preparations made from 20-50 pieces of freeze-dried, 20-microm thick, microdissected samples of tissue from canine right atrium, the AV nodal region, and left ventricle. Basal and NaF-stimulated adenylylcyclase activity (mean +/- SEM, n = 6) were 7.2 +/- 0.4 and 72.4 +/- 7.5 in atrial, 15.6 +/- 1.3 and 58.8 +/- 4.7 in AV nodal, and 6.4 +/- 0.9 and 66.7 +/- 5.0 in ventricular tissues, respectively. Isoproterenol (10(-7)-10(-4) M) increased adenylylcyclase activity in a dose-dependent fashion in three different regions. The isoproterenol (10(-6) M)-stimulated adenylylcyclase activity (n = 6) was 14.4 +/- 1.3 in atrial, 21.9 +/- 1.6 in AV nodal and 13.4 +/- 1.4 in ventricular tissues. Adenosine (10(-3) M) and carbachol (10(-5) M) inhibited isoproterenol (10(-6) M)-stimulated adenylylcyclase activity to 10.1 +/- 1.1, 12.9 +/- 1.3 in atrial, 15.1 +/- 1.6, 15.5 +/- 1.2 in AV nodal, and 7.5 +/- 0.7, 11.9 +/- 1.2 in ventricular tissues, respectively. The results demonstrate that there are regional differences in adenylylcyclase activity under basal conditions and after adrenergic, purinergic, and cholinergic stimulation in the heart. Unlike adenosine, the inhibitory effects of cholinergic stimulation appear to be more specific for the AV node.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0160-2446
pubmed:author
pubmed:issnType
Print
pubmed:volume
29
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
734-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Measurement of adenylylcyclase activity in the AV nodal region of the canine heart: evidence for inhibition by adenosine and acetylcholine.
pubmed:affiliation
Cardiac Arrhythmia Center, Department of Medicine, University of Minnesota, Minneapolis, USA.
pubmed:publicationType
Journal Article, In Vitro