Linked Life Data

8994084

Source:http://linkedlifedata.com/resource/pubmed/id/8994084

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1997-3-26
pubmed:abstractText
The effects of low (10-100 microM) concentrations of tetracaine on intermembrane charge movement and on the rate of calcium release (Rrel) from the sarcoplasmic reticulum (SR) were studied in cut skeletal muscle fibres of the frog using the voltage clamp technique. The fibres were mounted in a single or double vaseline gap chamber to study the events near the contraction threshold or in a wide membrane potential range. Although the 'hump' component of charge movement (Q gamma) was suppressed to some extent, the voltage dependence and the parameters of the Boltzmann distribution were not modified significantly at tetracaine concentrations below 50 microM. At 50 and 100 microM of tetracaine the midpoint voltage of the Boltzmann distribution was shifted to higher membrane potentials and the steepness was decreased. The total available charge remained the same at all concentrations tested. Using fura-2 to measure calcium transients at 100 microM tetracaine the threshold for calcium release was found to be significantly shifted to more positive membrane potentials. Tetracaine reversibly suppressed both the early inactivating peak and the steady-level of Rrel but the concentration dependence of the effects was markedly different. The inactivation component of calcium release was decreased with a Hill coefficient of approximately 1 and half effective concentration of 11.8 microM while the steady-level was decreased with a Hill coefficient of greater than 2 and a half effective concentration of 47.0 microM. These results favour two sites of action where tetracaine would suppress the calcium release from the SR.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0142-4319
pubmed:author
pubmed:issnType
Print
pubmed:volume
17
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
647-56
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Concentration-dependent effects of tetracaine on excitation-contraction coupling in frog skeletal muscle fibres.
pubmed:affiliation
Department of Physiology, University Medical School Debrecen, Hungary.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't