Linked Life Data

7869396

Source:http://linkedlifedata.com/resource/pubmed/id/7869396

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
1995-3-27
pubmed:abstractText
The heat produced by toad ventricle during manipulations of the inotropic state was measured using thermopiles, and some comparisons made to rat ventricle. The tension-independent heat, peak stress, and the tension-dependent heat increased when [Ca2+]o increased from 0.25 to 2 mM in Ringer. In 2 mM [Ca2+]o, tension-independent heat, peak stress, and tension-dependent heat were 3.1 +/- 0.4 mJ/g, 38.4 +/- 5.5 mN/mm2, and 0.49 +/- 0.06 units; about 25% of the tension-independent heat may relate to the Na(+)-K+ pump. At similar [Ca2+]o, rat ventricle produced a smaller tension-independent heat (1.6 +/- 0.2 mJ/g), and active heat per unit stress (0.22 +/- 0.01 units) than toad. Tension-independent heat, stress, and tension-dependent heat were increased by orciprenaline, and decreased by BDM. Ouabain increased the stress and tension-dependent heat but not the tension-independent heat. Five millimolar [Ca2+]o in HEPES buffer decreased the stress but increased the tension-dependent heat compared to 2 mM [Ca2+]o in Ringer. Ryanodine and CPA caused major reductions in force and tension-independent heat in rat, but had little effect on toad ventricle. In conclusion, our results suggest that in toad ventricle (a) the sarcoplasmic reticulum plays only a minor role in activation and relaxation, (b) the Na(+)-K+ pump contributes substantially to activation metabolism, (c) active metabolism is stimulated by increases in [Ca2+]o and (d) there is a larger tension-independent heat, a larger active metabolism per unit stress, and a lower basal metabolism than in rat papillary muscle. The energy cost of removing intracellular Ca2+ through the sarcolemma appears to be greater than uptake into sarcoplasmic reticulum.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0022-2828
pubmed:author
pubmed:issnType
Print
pubmed:volume
26
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1357-70
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed-meshheading:7869396-Animals, pubmed-meshheading:7869396-Biological Transport, pubmed-meshheading:7869396-Buffers, pubmed-meshheading:7869396-Bufo marinus, pubmed-meshheading:7869396-Calcium, pubmed-meshheading:7869396-Diacetyl, pubmed-meshheading:7869396-Energy Metabolism, pubmed-meshheading:7869396-Hot Temperature, pubmed-meshheading:7869396-Magnesium, pubmed-meshheading:7869396-Male, pubmed-meshheading:7869396-Metaproterenol, pubmed-meshheading:7869396-Myocardial Contraction, pubmed-meshheading:7869396-Myocardium, pubmed-meshheading:7869396-Ouabain, pubmed-meshheading:7869396-Papillary Muscles, pubmed-meshheading:7869396-Rats, pubmed-meshheading:7869396-Rats, Sprague-Dawley, pubmed-meshheading:7869396-Ryanodine, pubmed-meshheading:7869396-Sarcoplasmic Reticulum, pubmed-meshheading:7869396-Sodium-Potassium-Exchanging ATPase, pubmed-meshheading:7869396-Species Specificity, pubmed-meshheading:7869396-Stress, Mechanical
pubmed:year
1994
pubmed:articleTitle
Metabolism of toad ventricle during alterations to the inotropic state.
pubmed:affiliation
Department of Physiology, Monash University, Clayton, Victoria, Australia.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't