A nonradioactive iodide uptake assay for sodium iodide symporter function.
The standard assay for sodium iodide symporter (NIS) function is based on the measurement of radioiodide uptake ((125)I) in NIS-expressing cells. However, cost and safety issues have limited the method from being used widely. Here we describe a simple spectrophotometric assay for the determination of iodide accumulation in rat thyroid-derived cells (FRTL5) based on the catalytic effect of iodide on the reduction of yellow cerium(IV) to colorless cerium(III) in the presence of arsenious acid (Sandell-Kolthoff reaction). The assay is fast and highly reproducible with a Z' factor of 0.70. This procedure allows the screening of more than 800 samples per day and can easily be adapted to robotic systems for high-throughput screening of NIS function modulators. Using this method, the potency of several known inhibitors of NIS function was evaluated in a single day with high accuracy and reliability. Measured IC(50) values were essentially identical to those determined using Na(125)I.
Waltz
Fanny
F
Commissariat à l'Energie Atomique (CEA), Institut de Biologie et Technologies de Saclay (iBiTecS), Service de Chimie Bioorganique et de Marquage, Gif-sur-Yvette F-91191, France.
Pillette
Lucie
L
Ambroise
Yves
Y
D000818:Animals; D000838:Anions / Q000494:pharmacology; D001681:Biological Assay / Q000379:methods* / Q000592:standards; D001692:Biological Transport / Q000187:drug effects; D002384:Catalysis / Q000187:drug effects; D002460:Cell Line; D020128:Inhibitory Concentration 50; D007454:Iodides / Q000378:metabolism*; D007457:Iodine Radioisotopes; D051381:Rats; D012015:Reference Standards; D015203:Reproducibility of Results; D027981:Symporters / Q000378:metabolism*; D017186:Titrimetry; D000099209:Sodium-Iodide Symporters
D000838:Anions; D007454:Iodides; D007457:Iodine Radioisotopes; D027981:Symporters; D000099209:Sodium-Iodide Symporters