Faber J, Faber O, Wennlund A, Wahren J
J Clin Endocrinol Metab. 1984 Jul;59(1):147-50. doi: 10.1210/jcem-59-1-147.
The splanchnic extraction of 3,3'-diiodothyronine (3,3'-T2) and 3',5'-diiodothyronine (3',5'-T2) was studied in 7 hyperthyroid patients and 20 normal subjects employing the hepatic venous catheterization technique. A significant net uptake by splanchnic tissues was found for both diiodothyronines . The fractional splanchnic extraction calculated as the arterio-hepatic venous plasma concentration difference divided by the arterial concentration was unaffected by hyperthyroidism as compared to normal values. There was a close positive correlation between the arterio-hepatic venous concentration difference and arterial concentration, 3,3'-T2: r = 0.988, and 3',5'-T2: r = 0.932 (P less than 0.001). The splanchnic extraction was nonsaturable at endogenous plasma concentrations of 3,3'-T2 up to at least 17.0 ng/dl and of 3',5'-T2 up to at least 15.2 ng/dl. The data suggest that the splanchnic extraction of 3,3'-T2 and 3',5'-T2 obeys first order kinetics, the fractional extraction being unaffected by hyperthyroidism. Furthermore, changes in the net splanchnic extraction of 3,3'-T2 and 3',5'-T2 do not seem to contribute to changes in circulating levels of these iodothyronines. It is suggested that tissues other than the liver contribute significantly to the deiodination process both in normal and in hyperthyroid man.
采用肝静脉插管技术，对7例甲状腺功能亢进患者和20例正常受试者的内脏对3,3'-二碘甲腺原氨酸（3,3'-T2）和3',5'-二碘甲腺原氨酸（3',5'-T2）的摄取情况进行了研究。发现两种二碘甲腺原氨酸在内脏组织中均有显著的净摄取。以动脉-肝静脉血浆浓度差除以动脉浓度计算的内脏分数摄取率，与正常相比，不受甲状腺功能亢进的影响。动脉-肝静脉浓度差与动脉浓度之间存在密切的正相关，3,3'-T2：r = 0.988，3',5'-T2：r = 0.932（P＜0.001）。在内源性血浆浓度下，3,3'-T2至少达到17.0 ng/dl、3',5'-T2至少达到15.2 ng/dl时，内脏摄取不饱和。数据表明，3,3'-T2和3',5'-T2的内脏摄取遵循一级动力学，分数摄取不受甲状腺功能亢进的影响。此外，3,3'-T2和3',5'-T2的内脏净摄取变化似乎对这些碘甲腺原氨酸循环水平的变化没有贡献。提示在正常人和甲状腺功能亢进患者中，除肝脏外的其他组织对脱碘过程有显著贡献。
