Lukinius A, Wilander E, Westermark G T, Engström U, Westermark P
Department of Pathology, University Hospital, Uppsala, Sweden.
Diabetologia. 1989 Apr;32(4):240-4. doi: 10.1007/BF00285291.
Islet amyloid polypeptide is a novel 37 amino-acid-residues polypeptide which has been isolated from amyloid deposits in an insulinoma, and in human and cat islets of Langerhans. The molecule has 46% homology with the calcitonin gene-related peptide. Light microscopy examination of the pancreas shows that islet amyloid polypeptide immunoreactivity is restricted to the islet B cells. The present study utilized a rabbit antiserum against a synthetic peptide corresponding to positions 20-29 of islet amyloid polypeptide, a sequence without any amino-acid identity with calcitonin gene-related peptide. By applying the immunogold technique at the ultrastructural level, it was shown that both insulin and islet amyloid polypeptide immunoreactivity occurs in the central granular core of the human B cell secretory granules, while the A cells remain unlabelled. The demonstration that islet amyloid polypeptide is a granular protein of the B cells may indicate that it is released together with insulin. Further studies are necessary to evaluate the functional role of islet amyloid polypeptide.
胰岛淀粉样多肽是一种新的由37个氨基酸残基组成的多肽，已从胰岛素瘤以及人和猫的胰岛淀粉样沉积物中分离出来。该分子与降钙素基因相关肽有46%的同源性。胰腺的光学显微镜检查显示，胰岛淀粉样多肽免疫反应性仅限于胰岛B细胞。本研究使用了一种针对与胰岛淀粉样多肽第20 - 29位相对应的合成肽的兔抗血清，该序列与降钙素基因相关肽没有任何氨基酸同源性。通过在超微结构水平应用免疫金技术，结果显示胰岛素和胰岛淀粉样多肽免疫反应性均出现在人B细胞分泌颗粒的中央颗粒核心中，而A细胞未被标记。胰岛淀粉样多肽是B细胞的一种颗粒蛋白这一证明可能表明它与胰岛素一起释放。需要进一步研究以评估胰岛淀粉样多肽的功能作用。
