Endocrine Abstracts

When cultured in serum-free conditions, primary cultures of human thyroid cells display TSH-dependent iodide uptake and organification and iodide-dependent thyroid hormone synthesis. High iodide concentrations (>1 microM) inhibit thyroid hormone synthesis but iodide (0.1 microM) is obligatory for thyroid hormone secretion into the medium. We have performed in vitro studies examining the regulation of iodide transport and organification in cells preincubated in varying conce...