Linked Life Data

2071339

Source:http://linkedlifedata.com/resource/pubmed/id/2071339

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
1991-8-21
pubmed:abstractText
Ascorbic acid is concentrated in various ocular compartments where it is thought to protect diurnal animal species against damaging effects of ultraviolet radiation. The authors evaluated the possibility that corneal endothelial cells have specific transport and/or metabolic properties that deliver ascorbic acid to the stroma. Bovine corneal endothelial cells were grown to confluence in multiple-well plates. Individual groups of cells (approximately 10(4)) were then incubated at various times at 34 degrees C in a physiologic buffer that contained a 10 microM level of 14C-labeled ascorbic acid or the oxidized product, dehydro-L-ascorbic acid. Endothelial cells take up dehydro-L-ascorbic acid at least seven times as rapidly as they take up ascorbic acid. After 30 sec of incubation with 14C-dehydro-L-ascorbic acid, most of the label accumulated in the cell is in the reduced form. Uptake is inhibited by cyanide and iodoacetamide but is unaffected by ouabain. Exposure of cultured cells to various intermediates in the energy metabolism pathways reduced uptake of ascorbic acid but had a minor effect on uptake of the oxidized molecule. These results suggest that the cornea has transport and metabolic capacity to extract dehydro-L-ascorbic acid from aqueous humor and reduce it, thus providing a source of ascorbic acid for corneal protection. This also would maintain "total" ascorbic acid of aqueous humor in the reduced state.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0146-0404
pubmed:author
pubmed:issnType
Print
pubmed:volume
32
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2266-71
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Ascorbic acid uptake and metabolism by corneal endothelium.
pubmed:affiliation
Department of Physiology, University of North Dakota, Grand Forks.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't