Baxter R C, Brown A S, Turtle J R
Clin Chem. 1982 Mar;28(3):488-95.
We raised an antiserum (Tr4) in rabbits against a basic somatomedin C-like peptide preparation. Using high-immunoreactivity somatomedin C tracer, we compared the performance of radioimmunoassays in which we used the Tr4 antiserum and a well-characterized somatomedin C antiserum distributed by the National Pituitary Agency (NPA) with that of the human placental-membrane somatomedin radioreceptor assay (RRA). In their cross reactivity toward various somatomedin-like and unrelated peptides, the two radioimmunoassay methods were almost identical, although NPA antiserum, with about fourfold higher titer than Tr4 antiserum, showed a slightly greater sensitivity for most peptides tested. Radioimmunoassay of acid-ethanol-extracted plasma samples from normal persons and acromegalic, hypopituitary, hypothyroid, and renal-failure patients revealed no analytical differences between the antisera (for 122 samples, r = 0.979 between methods). Somatomedin values for acromegalic and hypopituitary samples showed no overlap with normals. Values for hypothyroid and pre-dialysis renal-failure samples were significantly lower than normal. By comparison, the RRA showed greater cross reactivity toward some somatomedin-like peptides and gave significantly lower values than radioimmunoassay for acromegalic and hypothyroid plasma extracts, and significantly higher value for hypopituitary and renal-failure samples. We conclude that the radioimmunoassay methods clearly are of greater diagnostic value than RRA for clinical somatomedin measurement.
我们用一种碱性类生长调节素C样肽制剂在兔体内制备了抗血清（Tr4）。使用高免疫反应性的生长调节素C示踪剂，我们比较了放射免疫分析的性能，在这些分析中我们使用了Tr4抗血清和由国家垂体机构（NPA）分发的一种特性明确的生长调节素C抗血清，以及人胎盘膜生长调节素放射受体分析（RRA）的性能。在对各种类生长调节素样肽和无关肽的交叉反应性方面，两种放射免疫分析方法几乎相同，尽管NPA抗血清的效价比Tr4抗血清高约四倍，对大多数测试肽显示出略高的灵敏度。对正常人和肢端肥大症、垂体功能减退、甲状腺功能减退和肾衰竭患者的酸乙醇提取血浆样本进行放射免疫分析，结果显示两种抗血清之间没有分析差异（对于122个样本，两种方法之间的r = 0.979）。肢端肥大症和垂体功能减退样本的生长调节素值与正常样本没有重叠。甲状腺功能减退和透析前肾衰竭样本的值显著低于正常水平。相比之下，RRA对一些类生长调节素样肽显示出更大的交叉反应性，对于肢端肥大症和甲状腺功能减退血浆提取物，其值显著低于放射免疫分析，而对于垂体功能减退和肾衰竭样本，其值显著更高。我们得出结论，对于临床生长调节素测量，放射免疫分析方法显然比RRA具有更大的诊断价值。
