Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4 Suppl
pubmed:dateCreated
1991-11-20
pubmed:abstractText
We have studied the effects of hypo- and hyperthyroidism on sarcolemmal (SL) and sarcoplasmic reticular (SR) ion transport processes and mitochondrial energy production in rat heart. The following conclusions were derived. 1) Compared with euthyroid state, hyperthyroidism led to increased SR Ca(2+)-accumulation. In SL, the activities of Ca(2+)-stimulated adenosine triphosphatase (ATPase), ATP-dependent Ca2+ pumping, and Na(+)-Ca2+ exchanger were not affected; but ouabain-sensitive Na(+)-K(+)-ATPase activity was enhanced. 2) Hypothyroidism resulted in depressed activities of Ca2+ pumps both in SL and SR. In SL, the Na(+)-K(+)-ATPase activity was decreased, but Na(+)-Ca2+ exchange was unaltered. 3) Thus slower relaxation of the hypothyroid myocardium may be attributed to depressed functioning of Ca2+ pumps in SR and SL, whereas faster relaxation of the hyperthyroid heart may be based on increased Ca(2+)-pumping activity of SR. 4) Hyperthyroidism and hypothyroidism, respectively, led to enhanced and decreased rates of mitochondrial phosphocreatine synthesis. The thyroid state appears to control the functional coupling between mitochondrial creatine kinase and ATP-ADP translocase: the energy of oxidative phosphorylation was transformed into phosphocreatine more effectively in mitochondria from hypothyroid hearts than in those from hyperthyroid hearts.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
261
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
66-71
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Thyroid control over membrane processes in rat heart.
pubmed:affiliation
Laboratory of Hormonal Regulation, Tartu University, Estonia, USSR.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't