Chloride channel blockers inhibit the Na+/I- symporter in thyroid follicles in culture.
Porcine thyroid cells in culture are able to reorganize into well-polarized follicle-like structures in the presence of cAMP analogs. These follicles exhibit on their basolateral membrane domain the Na+/I- symporter which allows iodide to accumulate in the thyrocytes. The initial rate of iodide influx through the Na+/I- symporter is inhibited up to 98% by the chloride channel blockers. 5 nitro-2(3-phenylpropylamino)benzoic acid and 3',5-Dichlorodiphenylamine-2-carboxylic acid are the most effective inhibitors, with a K0.5 value of 60 microM. This inhibition is not secondary to inhibition of chloride transport. Other chloride transporter blockers have been studied but showed lesser activities.
INSERM, Unité 270, Faculté de Médecine Nord, Marseille, France.
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Gerard
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Rigot
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Penel
D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid / Q000494:pharmacology; D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone / Q000494:pharmacology; D002352:Carrier Proteins / Q000037:antagonists & inhibitors*; D002478:Cells, Cultured; D018118:Chloride Channels / Q000037:antagonists & inhibitors*; D004159:Diphenylamine / Q000031:analogs & derivatives / Q000494:pharmacology; D005665:Furosemide / Q000494:pharmacology; D006997:Hypochlorous Acid / Q000494:pharmacology; D007454:Iodides / Q000378:metabolism; D007457:Iodine Radioisotopes; D007700:Kinetics; D008565:Membrane Proteins / Q000037:antagonists & inhibitors*; D009579:Nitrobenzoates / Q000494:pharmacology; D011339:Probenecid / Q000494:pharmacology; D012964:Sodium / Q000378:metabolism; D013448:Sulfobromophthalein / Q000494:pharmacology; D013552:Swine; D027981:Symporters; D013961:Thyroid Gland / Q000187:drug effects / Q000378:metabolism*; D000099209:Sodium-Iodide Symporters
D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D015124:8-Bromo Cyclic Adenosine Monophosphate; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; D002352:Carrier Proteins; D018118:Chloride Channels; D004159:Diphenylamine; D005665:Furosemide; D006997:Hypochlorous Acid; D007454:Iodides; D007457:Iodine Radioisotopes; D008565:Membrane Proteins; D009579:Nitrobenzoates; D011339:Probenecid; D012964:Sodium; D013448:Sulfobromophthalein; D027981:Symporters; D000099209:Sodium-Iodide Symporters; C059537:3',5-dichlorodiphenylamine-2-carboxylic acid; C058176:5-nitro-2-(3-phenylpropylamino)benzoic acid; C044258:8-chloro-cyclic adenosine monophosphate