Linked Life Data

1192554

Source:http://linkedlifedata.com/resource/pubmed/id/1192554

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1976-2-9
pubmed:abstractText
Microelectrode and isometric recording techniques were used to evaluate the effects of acetycholine (ACh) on depressed isolated preparations of dog and cat atrial muscle. Atrial muscles were maintained at 36-37 degrees C with warmed Tyrode's solution and were stimulated at frequencies of 30 or 60/min. Depolarization to resting potentials of approximately -50 mv was noted (1) after excessive stretch was applied, (2) in muscles obtained from cats in overt right heart failure, and (3) during exposure of the muscles to excessive concentrations of acetylstrophanthidin or lidocaine. Depolarized muscles demonstrated action potentials of smaller amplitude and rate of rise. Exposure to ACh (2.7 X 10(-6)M) had a minimal effect on resting potential in normal dog and cat atrial muscle and was accompanied by significant negative inotropic actions. The same concentration of ACh markedly increased resting potential and action potential amplitude and induced positive inotropic effects in depolarized muscles; these effects also occurred during beta-adrenergic blockade. We suggest that the positive inotropic effect of ACh in depressed muscles may result from (1) a more synchronous contraction of cells within each muscle, (2) recruitment of previously quiescent cells in contraction, (3) possibly increased calcium inflow in individual cells during depolarizations of greater magnitude, and (4) an increase in the number of interacting sites between actin and myosin after resting potential is improved.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0009-7330
pubmed:author
pubmed:issnType
Print
pubmed:volume
37
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
542-9
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1975
pubmed:articleTitle
Acetylcholine-induced reversal of canine and feline atrial myocardial depression during stretch, cardiac failure, and drug toxicity.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.