Linked Life Data

2895932

Source:http://linkedlifedata.com/resource/pubmed/id/2895932

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1270
pubmed:dateCreated
1988-5-26
pubmed:abstractText
The process of tension repriming and the phenomenon of tension potentiation after premature stimulation (post-extrasystolic potentiation, PESP) were studied in the adult guinea pig atrium. The following results were obtained. (i) Reducing extracellular calcium, [Ca]o, to 50% of normal did not significantly change the rate of tension repriming. However, in the presence of 5 microM isoprenaline (which greatly speeded up repriming) the same reduction in [Ca]o slowed down the repriming process. (ii) Increases in the rate of stimulation enhanced the rate of tension repriming in a control medium, but this rate-dependence was absent in the presence of isoprenaline. (iii) Isoprenaline (20 microM) abolished PESP. A reduction in [Ca]o or the addition of verapamil (still with isoprenaline) partly restored tension potentiation. In neonatal guinea pig atria, a large PESP was evident, which was only slightly reduced by isoprenaline. These results are interpreted as reflecting changes induced by isoprenaline in the degree of filling of sarcoplasmic reticulum (SR) stores with calcium, and in the rate of calcium recycling between uptake and release sites within the SR network. The large PESP found in the neonate, and its relative insensitivity to isoprenaline was interpreted as reflecting a scarcity of SR. This implies that tension potentiation may also reflect changes in sarcolemmal calcium currents.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0080-4649
pubmed:author
pubmed:issnType
Print
pubmed:day
23
pubmed:volume
233
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
33-43
pubmed:dateRevised
2007-4-30
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Tension reactivation and potentiation in guinea pig atrium: the effects of isoprenaline, calcium and rate changes.
pubmed:affiliation
Department of Physiology, Hebrew University Medical School, Jerusalem, Israel.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't