Chabaud O, Gruffat D, Venot N, Desruisseau-Gonzalvez S
INSERM Unité 270, Faculté de Médicine Nord Marseille, France.
Cell Biol Toxicol. 1992 Jul-Sep;8(3):9-17. doi: 10.1007/BF00130506.
Different processes implied in thyroid hormonogenesis (thyroglobulin, thyroperoxidase and hydrogen peroxide generating system expressions) and their regulation by TSH and iodide have been studied using porcine thyroid cells cultured in porous bottomed chambers. This system allowed to reproduce the functional bipolarity. Cells form a tight and polarized monolayer. Both apical and basolateral poles of epithelial cells were independently accessible and the cell layer separated two compartments which can contain different media. A major polarized secretion of thyroglobulin into the apical compartment was observed; it was increased in the presence of TSH as well as the thyroglobulin synthesis and mRNA level. These TSH effects were the consequence of adenylcyclase stimulation. Active transport of iodide, iodination of thyroglobulin and hormonosynthesis took place only in the presence of TSH. These steps occurred at the apical pole of cells. In the culture chamber system, thyroglobulin was weakly iodinated (6 atoms of iodide per mole of thyroglobulin; in vivo up to 40 atoms per mole) but hormonogenesis efficiency was close to this one observed in vivo (40%). Iodide concentrations higher than 0.5 microM daily added to the basal medium inhibited iodination of thyroglobulin and hormonosynthesis. Some components contained in culture media were inhibitors for iodination when they were present in the apical medium such as vitamins, amino acids and phenol red. The culture system appears to be interesting for pharmacological and toxicological studies.
利用培养于多孔底部培养室中的猪甲状腺细胞，研究了甲状腺激素生成过程中涉及的不同过程（甲状腺球蛋白、甲状腺过氧化物酶和过氧化氢生成系统的表达）及其受促甲状腺激素（TSH）和碘化物的调节。该系统能够重现功能双极性。细胞形成紧密且极化的单层。上皮细胞的顶端和基底外侧极均可独立接触，细胞层分隔两个可含有不同培养基的隔室。观察到甲状腺球蛋白向顶端隔室的主要极化分泌；在TSH存在时以及甲状腺球蛋白合成和mRNA水平均增加。这些TSH效应是腺苷酸环化酶受刺激的结果。碘化物的主动转运、甲状腺球蛋白的碘化和激素合成仅在TSH存在时发生。这些步骤发生在细胞的顶端极。在培养室系统中，甲状腺球蛋白碘化程度较弱（每摩尔甲状腺球蛋白含6个碘原子；体内每摩尔可达40个原子），但激素生成效率接近体内观察到的效率（40%）。每天向基础培养基中添加高于0.5微摩尔的碘化物浓度会抑制甲状腺球蛋白的碘化和激素合成。当培养基中的某些成分存在于顶端培养基中时，如维生素、氨基酸和酚红，它们是碘化的抑制剂。该培养系统对于药理学和毒理学研究似乎很有意义。
