Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1978-4-17
pubmed:abstractText
The kinetics of uptake of Ca(2+) by rat heart mitochondria were studied by a spectrophotometric method with Arsenazo III indicator. The exponential rate coefficients measured with or without added phosphate increase with the amount of Ca(2+) added up to about 24mum. Evidence is given that the effect is attributable to a combination of formation of chelates at low concentrations to act as Ca(2+) buffers, with co-transport of substrate to provide more respiratory fuel. The inhibitory effect of Mg(2+) depends on the Ca(2+) concentration, so with a constant [Mg(2+)] the low concentrations of Ca(2+) are most inhibited, and the rate coefficients are still more Ca(2+)-dependent. Ca(2+) uptake is slowed by local anaesthetics such as butacaine and dibucaine, and also by propranolol and palmitoyl-CoA. After an uptake, the release of Ca(2+) was investigated. The spontaneous release involves an initially slow and small appearance of free Ca(2+) and is followed by an auto-accelerated phase. The release is accompanied by a gradual decrease in internal ATP; it is initiated by palmitoyl-CoA (reversed by carnitine), by lysophosphatidylcholine, by Na(+) salts (reversed by oligomycin) and by K(+) salts added to a K(+)-free medium containing valinomycin. The process is probably a response to an increased energy load imposed on the mitochondria by the various conditions, which include the spontaneous action of phospholipase activated by traces of Ca(2+). The problem of how much mitochondrial activity is participating in normal heart Ca(2+) turnover is discussed, and experiments showing only 7-14% exchange of the mitochondrial Ca(2+) occurring in vivo in 10 or 20min are reported.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/204287-1093479, http://linkedlifedata.com/resource/pubmed/commentcorrection/204287-1176452, http://linkedlifedata.com/resource/pubmed/commentcorrection/204287-14304890, http://linkedlifedata.com/resource/pubmed/commentcorrection/204287-14304892, http://linkedlifedata.com/resource/pubmed/commentcorrection/204287-2609, http://linkedlifedata.com/resource/pubmed/commentcorrection/204287-320937, http://linkedlifedata.com/resource/pubmed/commentcorrection/204287-4225884, http://linkedlifedata.com/resource/pubmed/commentcorrection/204287-4231745, http://linkedlifedata.com/resource/pubmed/commentcorrection/204287-4248332, http://linkedlifedata.com/resource/pubmed/commentcorrection/204287-4250976, http://linkedlifedata.com/resource/pubmed/commentcorrection/204287-4311437, http://linkedlifedata.com/resource/pubmed/commentcorrection/204287-4344129, http://linkedlifedata.com/resource/pubmed/commentcorrection/204287-4548716, http://linkedlifedata.com/resource/pubmed/commentcorrection/204287-4855051, http://linkedlifedata.com/resource/pubmed/commentcorrection/204287-4922961, http://linkedlifedata.com/resource/pubmed/commentcorrection/204287-5049005, http://linkedlifedata.com/resource/pubmed/commentcorrection/204287-5114996, http://linkedlifedata.com/resource/pubmed/commentcorrection/204287-5135877, http://linkedlifedata.com/resource/pubmed/commentcorrection/204287-5639931, http://linkedlifedata.com/resource/pubmed/commentcorrection/204287-6036830, http://linkedlifedata.com/resource/pubmed/commentcorrection/204287-807125, http://linkedlifedata.com/resource/pubmed/commentcorrection/204287-819008, http://linkedlifedata.com/resource/pubmed/commentcorrection/204287-891942, http://linkedlifedata.com/resource/pubmed/commentcorrection/204287-985429
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0264-6021
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
168
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
447-56
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
1977
pubmed:articleTitle
The uptake and release of calcium by heart mitochondria.
pubmed:publicationType
Journal Article, In Vitro