Khan M N, Mirel R D, Ontjes D A, Ghosh A P, Lazarus L H, DiAugustine R P
Horm Res. 1984;20(2):129-37. doi: 10.1159/000179985.
Two antisera against synthetic ACTH(1-24) developed in rabbit showed strikingly different affinities toward the ACTH molecule. Both antisera (A-6 and A-7) were highly specific for the COOH-terminal region of ACTH(1-24). Antisera A-6 recognized ACTH(1-39) poorly. Radioimmunoassays (RIAs) using these antisera permitted the rapid (less than or equal to 18 h) quantitation of ACTH(1-24) (A-6) or ACTH(1-39) (A-7) at picogram levels. ACTH levels were determined on silicic acid extracts of rat and human plasma samples by the RIA specific for mid-region of ACTH(1-39) (A-7) and compared with that obtained by an ACTH(34-39) (C-terminal) RIA. In nearly all cases the C-terminal/mid-region ACTH ratios were less than 1.0, indicating that C-terminus of ACTH is more readily degraded by tissue or blood peptidases than are internal sequences. A solid-phase immunoadsorbent RIA specific for the extreme COOH-terminus of ACTH(1-24) was developed by coupling antiserum (A-6) to Sepharose 4B. This assay exhibited the same specificity as the soluble antiserum, yet tolerated relatively high concentrations of protein. Although the assay was suitable for rapid quantitation of ACTH(1-24), a decrease in sensitivity was observed in comparison to a conventional assay.
在兔子体内产生的两种抗合成促肾上腺皮质激素（ACTH）（1-24）抗血清对ACTH分子表现出显著不同的亲和力。两种抗血清（A-6和A-7）对ACTH（1-24）的COOH末端区域具有高度特异性。抗血清A-6对ACTH（1-39）的识别能力较差。使用这些抗血清的放射免疫测定法（RIA）能够快速（小于或等于18小时）定量皮克水平的ACTH（1-24）（A-6）或ACTH（1-39）（A-7）。通过针对ACTH（1-39）中间区域的特异性RIA（A-7）测定大鼠和人血浆样品硅酸提取物中的ACTH水平，并与通过ACTH（34-39）（C末端）RIA获得的结果进行比较。几乎在所有情况下，C末端/中间区域的ACTH比值均小于1.0，表明ACTH的C末端比内部序列更容易被组织或血液中的肽酶降解。通过将抗血清（A-6）偶联到琼脂糖4B上，开发了一种针对ACTH（1-24）极端COOH末端的固相免疫吸附RIA。该测定法与可溶性抗血清具有相同的特异性，但能耐受相对较高浓度的蛋白质。尽管该测定法适用于快速定量ACTH（1-24），但与传统测定法相比，灵敏度有所下降。
