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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1995-12-12
pubmed:abstractText
The purpose of this study was to test the effects of chloride channel blockers on iodide uptake in thyroid cells, in the hope of eventually using these blockers to identify and isolate a putative iodide transporter. The chloride channel blockers used in this report are derivatives of N-substituted anthranilic acid and were synthesized using published procedures. For these studies FRTL-5 cells, a line of continuous-growing rat thyroid cells, were used as a model system to study effects on iodide transport. In these cells, there are at least two ways for transmembrane iodide movements, a sodium-dependent influx step and a proposed channel that normally mediates iodide efflux. Two derivatives studied decreased iodide accumulation in FRTL-5 cells, but were found also to lower intracellular pH and ATP levels. To simplify interpretation of the effect of the drugs on iodide transport, we extended the studies using plasma membrane vesicles made from pig thyroid. Iodide entry in these vesicles depended on a sodium gradient and was independent of ATP levels. Iodide transport in plasma membrane vesicles and FRTL-5 cells was measured at 30 sec when the uptake was nearly linear and therefore likely to reflect iodide entry. The uptake was measured using three concentrations of iodide and three of drug. Kinetic analysis of the data described a competitive inhibition by the drugs with a Ki of approximately 250 microM. In summary, N-substituted anthranilic acid derivatives reversibly inhibit iodide entry in FRTL-5 cells and pig plasma membrane vesicles.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
1050-7256
pubmed:author
pubmed:issnType
Print
pubmed:volume
5
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
223-30
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Inhibition of iodide transport in rat thyroid cells using N-substituted anthranilic acid derivatives.
pubmed:affiliation
Laboratory of Biochemistry and Metabolism, National Institutes of Health, National Institute of Diabetes, Digestive Diseases and Kidney Diseases, Bethesda, Maryland 20892-1800, USA.
pubmed:publicationType
Journal Article