Rosselin G, Bataille D, Laburthe M, Duran-Garcia S
Pathol Biol (Paris). 1975 Dec;23(10):793-803.
Radioimmunoassay measures antigenic determinants of hormonal molecules in the plasma and tissues. These estimations carried out after fractionation in biological fluids, have revealed several immunological forms of the same hormone. These immunoreactive forms may be added to already well known elements of hormonal heterogeneity: formation of aggregate, polymerisation, links to transport proteins, microheterogeneity by silent mutation. The main problem is in the relationship of the various immunoreactive forms to the same hormonal sequence. The similar immunoreactive forms of high molecular weight (big hormone) usually have low biological activity and suggest the presence of prohormone; the suggestion of prohormonal nature depends on the chronology of the incorporation of labelled leucine and enzymatic transformation of prohormone with low biological into active hormone. The forms with high molecular weight and similar immunological activity may be of another nature. Thus, it has been shown that the biosynthetic nature of a compound such as big big insulin in the rat is doubtful owing to the absence of specific incorporation of labelled leucine into the immunoprecipitate of this fraction. The significance of low molecular weight forms is still little known. There may be breakdown products, biologically active products or biosynthetic products. An example of these forms is supplied by the existence of an alpha sub-unit of gonadotrophin present in the plasma of menopausal women. The interest of analytical methods by radio-receptor, stimulation of cyclase activity in the identification of biological activity of immunoreactive forms, is discussed in relation to immunological forms of enteroglucagon. An unusual aspect of the evolutive and adaptative character of hormonal heterogeneity is given by the gastro-intestinal hormones: secretin, vasoactive intestinal polypeptide and enteroglucagon, have similar structure and mode of action; however, the existence of a specific receptor is a sign of their functional differentiation at molecular level.
放射免疫测定法可检测血浆和组织中激素分子的抗原决定簇。在生物体液分级分离后进行的这些测定揭示了同一激素的几种免疫形式。这些免疫反应形式可能会增加激素异质性的已知因素：聚集体的形成、聚合、与转运蛋白的连接、沉默突变导致的微异质性。主要问题在于各种免疫反应形式与同一激素序列的关系。高分子量（大激素）的相似免疫反应形式通常生物活性较低，提示存在前激素；前激素性质的推测取决于标记亮氨酸掺入的时间顺序以及低生物活性前激素向活性激素的酶促转化。高分子量且免疫活性相似的形式可能具有另一种性质。因此，已表明大鼠体内诸如大大胰岛素这样的化合物的生物合成性质令人怀疑，因为在该级分的免疫沉淀物中未发现标记亮氨酸的特异性掺入。低分子量形式的意义仍鲜为人知。它们可能是分解产物、生物活性产物或生物合成产物。绝经后女性血浆中存在促性腺激素α亚基就是这些形式的一个例子。结合肠高血糖素的免疫形式，讨论了放射受体分析方法、环化酶活性刺激在鉴定免疫反应形式生物活性方面的意义。胃肠激素：促胰液素、血管活性肠肽和肠高血糖素，具有相似的结构和作用方式，这体现了激素异质性进化和适应性特征的一个不同寻常的方面；然而，特异性受体的存在是它们在分子水平功能分化的标志。
