Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6 Pt 2
pubmed:dateCreated
1988-7-15
pubmed:abstractText
We examined mechanisms by which Ca enters cultured myocardial cells during posthypoxic reoxygenation. Monolayer cultures of chick embryo ventricular cells were prepared from hearts 10 days in ovo. Cells were exposed to hypoxic conditions (PO2 less than 1.5 Torr), and 45Ca uptake during subsequent reoxygenation was then examined in the absence and presence of modulators of Ca channel-dependent Ca entry and Na-Ca exchange. Modulation of Ca entry by free radical-scavenging enzymes was also examined. Hypoxia for 120 min followed by reoxygenation increased Ca content from 1.9 to 6.1 nmol/mg protein (P less than 0.05) at 30 min. Verapamil (10(-5) M) added before reoxygenation reduced Ca overload to 3.1 +/- 0.2 nmol/mg protein (P less than 0.05), but both verapamil and BAY K 8644 were without effect on modulating Ca entry if added 30 min after reoxygenation. 24Na content of cells increased from 70 nmol/mg protein in control cells to 157 nmol/mg protein (P less than 0.05) after hypoxia and reoxygenation, favoring Ca entry via Na-Ca exchange. Dichlorobenzamil significantly ameliorated reoxygenation-induced Ca overload, as did catalase and superoxide dismutase. We conclude that reoxygenation-induced Ca overload is unlikely to occur via the Ca channel. It occurs in part via Na-Ca exchange and is substantially ameliorated by enzymatic O2 free radical scavengers.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
254
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
H1133-41
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Mechanisms of reoxygenation-induced calcium overload in cultured chick embryo heart cells.
pubmed:affiliation
Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't