Age-dependent variation of follicular size and expression of iodine transporters in human thyroid tissue (original) (raw)

The high sensitivity of the thyroid gland to the carcinogenic effects of radiation during childhood contrasts with the absence of demonstrable carcinogenic effects of radiation in adults. To better understand these age-related variations, we studied follicular morphometry, functional status, and proliferative activity in 31 thyroid glands removed from relatives of medullary thyroid carcinoma patients, with ages ranging from 3 to 39 y. The mean follicular diameter (MFD) was estimated, and immunohistochemistry was performed with antibodies directed to molecules involved in iodide transport (Na(+)/I(-) symporter [NIS], pendrin, and apical iodide transporter), in organification (thyroperoxidase [TPO] and Duox), in cell cycle and growth (Ki-67, cyclin A and D1, and galectin-3), and in angiogenesis (vascular endothelial growth factor and nitric oxide synthase III [NOSIII]). Compared with older patients, patients who were < or =12 y old had a smaller MFD (P < 0.001) and more frequent...