Ochi Y, Hachiya T, Miyazaki T, Kajita Y, Yoshimura M
Endocrinol Jpn. 1979 Feb;26(1):1-7. doi: 10.1507/endocrj1954.26.1.
In an attempt to analyze thyroid stimulators in serum we developed an assay procedure using hTSH radioimmunoassay (RIA) in combination with receptor competition. The principle of this method is the determination by RIA of hTSH displaced by other thyroid stimulators from a thyroidal receptor preparation which previously bound unlabelled hTSH. Practically 4 microunits of hTSH were bound with human or bovine receptor, and then hTSH displaced by addition of test serum (0.1 ml) or samples dissolved in serum (0.1 ml) was measured by RIA. This assay can determine the thyroid stimulators other than hTSH in serum that has the displacement activity of 0.5-4.0 microunits of hTSH in the useful range, such as mU/ml level of bovine TSH or rat TSH. Cholera toxin that has the thyroid stimulating activity like TSH also showed the displacement of the bound hTSH. This assay is not applicable for the human serum with more than 5 microunits/ml of TSH, because the assay value is over estimated by the free hTSH derived from the test serum. On the other hand, eighteen sera with high LATS activity and 42 sera with negative LATS activity from patients with untreated hyperthyroidism did not show any displacement. This might be due to the lower binding activity of LATS with hTSH receptor or the lower sensitivity of this assay method. Although it is difficult to use this assay clinically because of its low sensitivity, increased TSH in animal serum can be determined by this assay. The principle of this method may be also useful for examining the receptor binding of other peptide hormone that can be determined by an RIA method.
为了分析血清中的甲状腺刺激物，我们开发了一种检测方法，该方法使用人促甲状腺激素放射免疫分析（RIA）结合受体竞争。该方法的原理是通过RIA测定其他甲状腺刺激物从先前结合未标记人促甲状腺激素的甲状腺受体制剂中置换出的人促甲状腺激素。实际上，4微单位的人促甲状腺激素与人或牛的受体结合，然后通过RIA测量加入测试血清（0.1毫升）或溶解在血清中的样品（0.1毫升）所置换出的人促甲状腺激素。该检测方法可以测定血清中除人促甲状腺激素以外的具有0.5 - 4.0微单位人促甲状腺激素置换活性的甲状腺刺激物，例如牛促甲状腺激素或大鼠促甲状腺激素的毫国际单位/毫升水平。具有类似促甲状腺激素甲状腺刺激活性的霍乱毒素也显示出结合的人促甲状腺激素的置换。该检测方法不适用于促甲状腺激素超过5微单位/毫升的人血清，因为检测值会被测试血清中游离的人促甲状腺激素高估。另一方面，来自未经治疗的甲状腺功能亢进患者的18份具有高长效甲状腺刺激素（LATS）活性的血清和42份具有阴性LATS活性的血清未显示任何置换。这可能是由于LATS与人促甲状腺激素受体的结合活性较低或该检测方法的灵敏度较低。尽管由于其低灵敏度在临床上难以使用该检测方法，但该检测方法可以测定动物血清中升高的促甲状腺激素。该方法的原理也可能有助于检查其他可以通过RIA方法测定的肽激素的受体结合情况。
