Gärtner R, Dugrillon A, Bechtner G
Department of Internal Medicine, Klinikum Innenstadt, Ludwig-Maximilians University, Munich, Germany.
Acta Med Austriaca. 1996;23(1-2):47-51.
Different iodolipids have been identified within the last decades in thyroid cells exposed to iodine in vitro as well as in vivo. Iodolipids have been supposed to be involved in thyroid autoregulation, but no specific compounds could be found. A new approach was stimulated by the finding that rat thyroid lobes were able to iodinate arachidonic acid and docosahexaenoic acids in vitro. Meanwhile 6-iodo-5 hydroxy-eicosatrienoic acid (delta-iodolactone) has been identified in human thyroid tissue, but only after treating the patients with high doses of iodine before thyroidectomy, whereas in untreated endemic goiter this delta-iodolactone could not be found. In rats treated with iodolactones, methimazole induced goiter formation could be prevented. In human and porcine thyroid cells in vitro, delta-iodolactone inhibited epidermal growth factor (EGF) induced proliferation in 50-fold lower concentrations than iodide itself. Furthermore it could be demonstrated that only the IP3-, but not the cAMP generation in porcine thyroid cells could be inhibited by this compound. Also a structure specifity for delta-iodolactones for the biological activity could be shown. We will summarize and discuss these important new findings on the role of iodolactones on thyroid growth.
在过去几十年里，已在体外和体内接触碘的甲状腺细胞中鉴定出不同的碘脂质。碘脂质被认为参与甲状腺自身调节，但尚未发现特定化合物。大鼠甲状腺叶能够在体外碘化花生四烯酸和二十二碳六烯酸这一发现激发了一种新方法。与此同时，已在人类甲状腺组织中鉴定出6-碘-5-羟基-二十碳三烯酸（δ-碘内酯），但这只是在甲状腺切除术前用高剂量碘治疗患者之后，而在未经治疗的地方性甲状腺肿中未发现这种δ-碘内酯。在用碘内酯处理的大鼠中，可预防甲巯咪唑诱导的甲状腺肿形成。在体外培养的人类和猪甲状腺细胞中，δ-碘内酯抑制表皮生长因子（EGF）诱导的增殖所需的浓度比碘化物本身低50倍。此外，可以证明该化合物仅能抑制猪甲状腺细胞中IP3（肌醇三磷酸）的产生，而不能抑制cAMP（环磷酸腺苷）的产生。还可以显示出δ-碘内酯生物活性的结构特异性。我们将总结并讨论这些关于碘内酯在甲状腺生长中作用的重要新发现。
