Linked Life Data

457680

Source:http://linkedlifedata.com/resource/pubmed/id/457680

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
15
pubmed:dateCreated
1979-9-27
pubmed:abstractText
This study examines thiamin transport in isolated rat hepatocytes and its relationship to thiamin phosphorylation. In an Na+ medium, [35S]thiamin, 3 microM, was accumulated rapidly by the cells, and a near study state intra-/extracellular distribution ratio of 3 was attained in 1 min. However, the uptake of radioactivity continued to increase with time owing principally to the accumulation of [35S]thiamin pyrophosphate (TPP). In a choline, Li+ or K+ medium, the steady state intra-/extracellular distribution ratio of [35S]thiamin was decreased to less than or equal to 1.1. Accordingly, the rate of formation of [35S]TPP also decreased. Ouabain and uncouplers of oxidative phosphorylation significantly lowered the distribution ratio of intra-/extracellular [35S]thiamin. These data indicate that thiamin transport in liver is concentrative, Na+-dependent, and dependent on biological energy. Additionally, they suggest that thiamin transport plays a significant role in governing the rate of synthesis of TPP. Neither pyrithiamin, an inhibitor of thiamin pyrophosphokinase nor o-benzoylthiamin disulfide, a permeable thiamin analog, affected the distribution ratio of intra-/extracellular [35S]thiamin, but preferentially inhibited the phosphorylation of [35S]thiamin. By contrast, amprolium primarily inhibited uptake. These data suggest that thiamin transport and phosphorylation can be differentiated by the action of appropriate inhibitors.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
254
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7265-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1979
pubmed:articleTitle
Transport and metabolism of thiamin in isolated rat hepatocytes.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, Non-P.H.S.