Linked Life Data

7563016

Source:http://linkedlifedata.com/resource/pubmed/id/7563016

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1995-11-20
pubmed:abstractText
M2-cholinergic receptor activation by acetylcholine (ACh) is known to cause a negative inotropic and chronotropic action in atrial tissues. This effect is still controversial in ventricular tissues. The ACh-sensitive muscarinic K+ channel (IK(ACh)) activity was characterized in isolated feline atrial and ventricular myocytes using the patch-clamp technique. Bath application of ACh (1 microM) caused shortening of action potential duration without prior stimulation with catecholamines in atrial and ventricular myocytes. Resting membrane potential was slightly hyperpolarized in both tissues. These effects of ACh were greater in atrium than in ventricle. ACh increased whole-cell membrane current in atrial and ventricular myocytes. The current-voltage (I-V) relationship of the ACh-induced current in ventricle exhibited inward-rectification whose slope conductance was smaller than that in atrium. In single channel recording from cell-attached patches, IK(ACh) activity was observed when ACh was induced in the pipette solution in both tissues. The channel exhibited a slope conductance of 47 +/- 1 pS (mean +/- SD, n = 14) in atrium and 47 +/- 2 pS (n = 10) in ventricle (not different statistically; NS). The open times were distributed according to a single exponential function with mean open lifetime of 2.0 +/- 0.3 msec (n = 14) in atrium and 1.9 +/- 0.3 msec (n = 10) in ventricle (NS); these conductance and kinetic properties were similar between the two tissues. However, the relationship between the concentration of ACh and single channel activity showed a higher sensitivity to ACh in atrium (IC50 = 0.03 microM) than in ventricle (IC50 = 0.15 microM).(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0022-2631
pubmed:author
pubmed:issnType
Print
pubmed:volume
145
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
143-50
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Characterization of the acetylcholine-sensitive muscarinic K+ channel in isolated feline atrial and ventricular myocytes.
pubmed:affiliation
Department of Medicine, Northwestern University Medical School, Chicago, IL 60611, USA.
pubmed:publicationType
Journal Article, Comparative Study