THYROXINE PROTEIN INTERACTIONS

而TBG、前白蛋白和白蛋白是公认的 人血浆中甲状腺激素结合系统，令人信服的证据， 缺乏与血浆脂蛋白的类似结合。 在一项系统的研究中， 用SepharoseCL-6 B层析法检测正常人血浆 与遗传性脂蛋白异常患者之间的相互作用 甲状腺激素和个体脂蛋白类（VLDL，LDL）之间的关系 和HDL）明确证明。 甲状腺素的结合更强 比三碘甲腺原氨酸，结合似乎取决于 脂蛋白的蛋白质部分。 无论这种互动， 占甲状腺激素运输的不到1-2%，发挥任何 生理作用需要进一步研究。 由于血清TBG水平通过免疫放射测定法测量（ESTA，Corning 非甲状腺疾病（NTI）患者的血清甲状腺素水平低于非甲状腺疾病（NTI）患者 通过放射免疫测定法（RIA）测量，已知的脂质的作用是 升高的NTI，和各种药物，测试了他们的能力， 抑制甲状腺素与TBG的结合。 不饱和脂肪酸与药物 如呋塞米、双氯芬酸、甲芬那酸等 抑制剂的 结果表明，RIA法比传统的放射免疫法更适合于测定 TBG-ELISA是一种简便、快速的检测NTI的方法， 甲状腺激素结合抑制剂。

While TBG, prealbumin and albumin constitute the universally accepted major thyroid hormone binding system in human plasma, convincing evidence for similar binding to plasma lipoproteins is lacking. In a systematic study using Sepharose CL-6B chromatography to examine plasma from normal subjects and patients with genetic lipoprotein abnormalities, the interaction between thyroid hormone and the individual lipoprotein classes (VLDL, LDL and HDL) was unequivocally demonstrated. Binding of thyroxine was greater than that of triiodothyronine, and binding appeared to depend on the protein moieties of the ipoproteins. Whether this interaction, which accounts for less than 1-2% of thyroid hormone transport, plays any physiological role requires further study. Since serum TBG levels measured by an immunoradiometric assay (IRM, Corning kit) in patients with nonthyroid illness (NTI) are lower than those measured by radioimmunoassay (RIA), the effect of lipids known to be elevated in NTI, and various drugs, were tested for their ability to inhibit the binding of thyroxine to TBG. Unsaturated fatty acids and drugs such as furosemide, diclofenac and mefenamic acid were effective inhibitors. It was concluded that RIA is preferable to IRM for measuring TBG in NTI, and that TBG-IRM is a convenient and rapid method to test for thyroid hormone binding inhibitors.