Sodium/iodide-symporter: distribution in different mammals and role in entero-thyroid circulation of iodide.
Författare
Summary, in English
The sodium (Na+)/iodide (I-)-symporter (NIS) is abundantly expressed and accumulates iodide in thyroid follicular cells. The NIS is also found in extrathyroidal tissues, particularly gastric mucosa. Controversies exist on the localization of extrathyroidal NIS. We have studied the presence of both NIS peptide and NIS messenger RNA (mRNA) in the digestive tract and thyroid from different mammals. The role of gastric NIS is enigmatic and we aimed to unravel its possible involvement in iodide transport. Methods: Distribution and expression of NIS were studied using immunocytochemistry and in situ hybridization. Iodide transport in the gastrointestinal tract was measured after oral or intravenous (i.v.) administration of 125I to rats with or without ligation of the pylorus. Results: All thyroid follicular cells in rat and mouse expressed NIS, whereas a patchy staining was noted in man, pig and guinea-pig. Gastric mucosa surface epithelium in all species and ductal cells of parotid gland in guinea-pig, rat and mouse expressed NIS. In parietal cells and in endocrine cells of intestines and pancreas NIS immunoreactivity but no NIS mRNA was found. Studies of 125I uptake showed marked iodide transport from the circulation into the gastric lumen. Conclusions: The localization of NIS varies slightly among mammals. To establish expression of NIS in a particular cell type the need to correlate the presence of both NIS protein by immunocytochemistry and NIS mRNA by in situ hybridization is emphasized. An entero-thyroidal circulation of iodide mediated principally by gastric NIS, but possibly also by NIS in salivary glands is suggested.
Avdelning/ar
- Neurogastroenterology
- Laryngoesofagologi, allergi och livskvalitet
- Medicinsk strålningsfysik, Lund
Publiceringsår
2002
Språk
Engelska
Sidor
129-137
Publikation/Tidskrift/Serie
Acta Physiologica Scandinavica
Volym
175
Issue
2
Fulltext
- Available as PDF - 403 kB
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Länkar
Dokumenttyp
Artikel i tidskrift
Förlag
Wiley-Blackwell
Ämne
- Radiology, Nuclear Medicine and Medical Imaging
- Cell and Molecular Biology
- Otorhinolaryngology
Status
Published
Forskningsgrupp
- Neurogastroenterology
- Laryngoesophagology, Allergy and Life Quality
ISBN/ISSN/Övrigt
- ISSN: 0001-6772