Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1993-3-4
pubmed:abstractText
The mechanism of damage to myocardial subcellular organelles was studied in iron-loaded rat myocardial cells in culture in an attempt to identify the primary target of iron's toxic effects. Lysosomes and sarcolemmal membranes were purified by fractionation of the postnuclear supernatant on a 6.7% colloidal polyvinylpyrrolidone-coated silica gradient. After 24-hour incubation with ferric ammonium citrate at a concentration of 20 micrograms/ml (0.36 mmol/L) iron, a selective depletion of polyunsaturated fatty acids was found in whole-cell homogenates, as well as in the postnuclear supernatant and sediment. Iron loading resulted in a sharp increase in the total activity of the lysosomal enzyme beta-hexosaminidase in unfractionated whole-cell homogenates, increased free enzyme activity, and loss of latent activity indicating increased lysosomal fragility. Conversely, iron loading resulted in a marked decrease in the activity of the sarcolemmal enzyme 5'-nucleotidase and a significant loss of total protein sulfhydryl group content. These studies in cultured heart cells are in agreement with previous observations indicating increased lysosomal fragility in iron-loaded hepatic and splenic tissues, attributed to increased membrane lipid peroxidation. In addition, the marked decrease in sarcolemmal 5'-nucleotidase activity and in total protein sulfhydryl group content imply that iron-induced peroxidative damage to membrane proteins may be a more important mechanism in the pathogenesis of altered myocardial function in the iron-loaded heart than formerly was recognized.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0022-2143
pubmed:author
pubmed:issnType
Print
pubmed:volume
121
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
127-34
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Iron loading of cultured cardiac myocytes modifies sarcolemmal structure and increases lysosomal fragility.
pubmed:affiliation
Department of Nutrition, Hebrew University Hadassah Medical School, Jerusalem, Israel.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't