Linked Life Data

8439537

Source:http://linkedlifedata.com/resource/pubmed/id/8439537

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
1993-3-29
pubmed:abstractText
The uptake characteristics of both the retinol and retinol-binding protein (RBP) moieties of the retinol-RBP complex by liver parenchymal cells (PC) in vitro were studied to assess whether retinol uptake is mediated by a cell-surface receptor for RBP. At 37 degrees C as well as 4 degrees C, [3H]retinol uptake from [3H]retinol-RBP showed a time-dependent increase, and was not saturable at concentrations exceeding the physiological concentration by more than a factor of 2 (3 microM). Uptake of [3H]retinol was not inhibited by a 10-fold molar excess of unlabeled retinol-RBP. Cell association of 125I-RBP at 37 and 4 degrees C was low and showed no time dependence. In addition, the association of 125I-RBP was not saturable at concentrations up to 3 microM. These data do not support the existence of a cell-surface receptor for RBP on rat liver PC. The uptake of [3H]retinol from RBP was also compared to the uptake of retinol from cellular retinol-binding protein (CRBP) and lactoglobulin. Uptake characteristics of [3H]retinol from CRBP and lactoglobulin were similar to that of [3H]retinol from RBP. Furthermore, a similar percentage of the [3H]retinol taken up by PC was metabolized into retinyl esters, irrespective of its carrier. These data suggest that the uptake of retinol and its subsequent metabolic processing do not depend on binding to RBP. The low level of cell association of 125I-binding proteins was not due to uptake, degradation, and secretion of ligand by PC. This suggests that retinol is dissociated from its binding protein before uptake by PC.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
23
pubmed:volume
32
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1727-33
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Retinol uptake from retinol-binding protein (RBP) by liver parenchymal cells in vitro does not specifically depend on its binding to RBP.
pubmed:affiliation
TNO Institute of Ageing and Vascular Research, Gaubius Laboratory, Leiden, The Netherlands.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't