Perez Cano R, Girgis S I, Galan Galan F, MacIntyre I
J Endocrinol. 1982 Mar;92(3):351-5. doi: 10.1677/joe.0.0920351.
To investigate whether human calcitonin (hCT) is preserved during the evolution of vertebrates, we studied extracts of avian (pigeon and chicken) thyroid and ultimobranchial glands (UBG) which have previously been reported to contain salmon calcitonin (sCT)- like molecules. A sensitive and specific radioimmunoassay for hCT, employing two antisera reacting with different regions of the molecule, was used in combination with high performance liquid chromatography (HPLC). We found that extracts of thyroid and UBG from pigeons and chickens contain, in addition to an immunoreactive sCT-like molecule (which is the major immunoreactive form), an hCT-like molecule comprising from 0.4 to 3.75% of the calcitonin content. The extracts produced full displacement of 125I-labelled hCT from both antisera and gave a parallel displacement curve. With HPLC, we found an immunoreactive hCT peak which was 5 ml earlier than the insulin marker and an immunoreactive sCT peak which was 12 ml later than the insulin marker. These results demonstrate the presence of two calcitonins in birds, and suggest the existence of two genes with different degrees of expression.
为了研究人类降钙素（hCT）在脊椎动物进化过程中是否得以保留，我们研究了禽类（鸽子和鸡）甲状腺及鳃后腺（UBG）的提取物，此前有报道称这些提取物中含有鲑鱼降钙素（sCT）样分子。我们使用了一种针对hCT的灵敏且特异的放射免疫分析法，该方法采用两种与分子不同区域发生反应的抗血清，并结合高效液相色谱法（HPLC）。我们发现，鸽子和鸡甲状腺及UBG的提取物中，除了一种免疫反应性sCT样分子（这是主要的免疫反应形式）外，还含有一种hCT样分子，其占降钙素含量的0.4%至3.75%。提取物使两种抗血清中的125I标记hCT完全被置换，并给出了平行的置换曲线。通过HPLC，我们发现一个免疫反应性hCT峰比胰岛素标记峰早5毫升出现，一个免疫反应性sCT峰比胰岛素标记峰晚12毫升出现。这些结果证明鸟类中存在两种降钙素，并提示存在两个表达程度不同的基因。
