Linked Life Data

9506966

Source:http://linkedlifedata.com/resource/pubmed/id/9506966

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
1998-4-16
pubmed:abstractText
We recently identified a novel prostaglandin transporter called PGT (Kanai, N., Lu, R., Satriano, J. A., Bao, Y., Wolkoff, A. W., and Schuster, V. L. (1995) Science 268, 866-869). Based on initial functional studies, we have hypothesized that PGT might mediate the release of newly synthesized prostaglandins (PG), epithelial transport of PGs, or metabolic clearance of PGs. Here we examined the mechanism of PGT transport as expressed in HeLa cells and Xenopus oocytes, using isotopic PG influx and efflux studies. In both native HeLa cells and oocytes, cell membranes were poorly permeable to PGs. In contrast, in oocytes injected with PGT mRNA, the PG influx permeability coefficient was 90-157 times that of oocytes injected with water. The rank order substrate profile was PGF2alpha approximately PGE2 > TXB2 >> 6 keto-PGF1alpha. PG influx displayed an overshoot with rapid accumulation of tracer PGE2, followed by a gradual return to baseline. Based on estimated oocyte volumes, the PGT-mediated accumulation of PGE2 reached steady state at intra-oocyte concentrations 25-fold higher than the external media. The accumulation of PG was not due to intracellular binding or metabolism. PGT-mediated uptake was ATP- and temperature-dependent, but not sodium-dependent, and was inhibited by disulfonic stilbenes, niflumic acid, and the thiol reactive anion MTSES (Na(2-sulfonatoethyl)methanethiosulfonate). [3H]PGE2 efflux from PGT-transfected HeLa cells was stimulated by external (trans) PGE2 in a dose-dependent fashion and was inhibited by bromcresol green and 4,4'-diisothiocyanatostilbene-2,2'-disulfonate. Membrane depolarization inhibited uptake of [3H]PGE2, consistent with a model of net outward movement of negative charge during the translocation event. These findings suggest that PGT mediates [3H]PGE2 accumulation via obligatory, electrogenic anion exchange.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
20
pubmed:volume
273
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6689-97
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Mechanism of prostaglandin E2 transport across the plasma membrane of HeLa cells and Xenopus oocytes expressing the prostaglandin transporter "PGT".
pubmed:affiliation
Renal Division, Department of Medicine, Physiology & Biophysics, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.