Linked Life Data

3168178

Source:http://linkedlifedata.com/resource/pubmed/id/3168178

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1988-11-4
pubmed:abstractText
We compared the response of ventricular muscle from adult and neonatal rats to hypercapnic acidosis. In adult muscle, acidosis caused an initial rapid fall of developed tension to 30 +/- 5% of control (mean +/- SEM, n = 6). However, tension recovered slowly to a steady state that was 56 +/- 6% of control. In neonatal muscle, acidosis caused a significantly smaller initial fall in tension to 43 +/- 3% (n = 8, p less than 0.05), but the tension then showed a subsequent slower fall to a steady state that was 29 +/- 4% of control, significantly less than in the adult (p less than 0.01). We have attempted to identify the mechanisms underlying these differences in response. In detergent-skinned myofibrils, reducing the pH from 7.0 to 6.5 caused a reduction in the pCa50 of 0.61 units in the adult muscle, but only 0.27 units in the neonatal ventricular muscle. Myofibrillar Ca2+ sensitivity in neonatal ventricular muscle is thus less susceptible to the effects of acidic pH than that of adult muscle. Since intracellular pH decreases rapidly on application of increased external CO2, these results are consistent with the finding that, initially, developed tension in neonatal muscles is less sensitive to the effects of acidosis. Sodium dodecylsulfate gel electrophoresis of myofibrillar preparations from adult and neonatal rats demonstrated differences in thin filament proteins, including troponin I, which may underlie the observed differences in Ca2+ sensitivity. In adult rat ventricular muscles, the slow recovery of tension during acidosis is associated with an increase in the amplitude of the Ca2+ transients to 263 +/- 34% of control (n = 4).(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0009-7330
pubmed:author
pubmed:issnType
Print
pubmed:volume
63
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
779-87
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Effects of acidosis on ventricular muscle from adult and neonatal rats.
pubmed:affiliation
Department of Physiology, University College London, England.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't