Linked Life Data

10321800

Source:http://linkedlifedata.com/resource/pubmed/id/10321800

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1999-6-29
pubmed:abstractText
Ascorbic acid serves a vital role as a pre-eminent antioxidant. In animals, it has been shown to be concentrated in granulosa and theca cells of the follicle, in luteal cells of the corpus luteum, and in the peripheral cytoplasm of the oocyte. We have previously identified hormonally-regulated ascorbic acid transporters in rat granulosa and luteal cells, and herein present preliminary evidence for the presence of a transporter for ascorbic acid in human granulosa-lutein cells. Granulosa-lutein cells were obtained from the follicular fluid of patients undergoing in-vitro fertilization. Following an overnight incubation, the cells were incubated with [14C]-ascorbic acid (0.15 microCi; 150 microM) and ascorbic acid uptake was determined. The uptake of ascorbic acid was saturable with a Michaeli's constant (Km) and maximum velocity (Vmax) of 21 microM and 3 pmol/10(6) cells/min respectively. Ouabain, low Na+ medium, and dinitrophenol significantly inhibited ascorbic acid uptake (P<0.05). Neither the presence of insulin, human chorionic gonadotrophin (HCG), insulin-like growth factor (IGF)-I, nor IGF-II affected the uptake of ascorbic acid in a statistically significant fashion. Following saturation of cellular uptake, the ascorbic acid level was estimated to be 1.04 pmoles/10(6) cells or approximately 1 mM, a high concentration similar to that seen in rat luteal cells. Active ascorbic acid transport in human granulosa-lutein cells appears to occur via a Na+ - and energy-dependent transporter, with high levels of ascorbic acid being accumulated in these cells.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
1360-9947
pubmed:author
pubmed:issnType
Print
pubmed:volume
5
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
299-302
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Identification and characterization of an ascorbic acid transporter in human granulosa-lutein cells.
pubmed:affiliation
Department of Obstetrics and Gynecology, Yale University School of Medicine, New Haven, CT 06520-8063, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.