Toshimori H, Narita R, Nakazato M, Asai J, Mitsukawa T, Kangawa K, Matsuo H, Takahashi K, Matsukura S
Internal Medicine, Miyazaki Medical College, Japan.
Virchows Arch A Pathol Anat Histopathol. 1991;418(5):411-7. doi: 10.1007/BF01605927.
Amyloid deposition is a common pathological feature in insulinoma and in the islets of the pancreas in type-2 diabetic patients. The present immunohistochemical study revealed that normal B-cells, insulinoma, and amyloid deposits in insulinoma and diabetic pancreatic islets were commonly immunoreactive with antiserum to C-terminal synthetic tetradecapeptide of human islet amyloid polypeptide (IAPP) (24-37). Amyloid fibrils in insulinoma were also positive to IAPP by immunoelectron microscopy. A high level of IAPP was detected in the plasma and tissue of a insulinoma patient by radioimmunoassay suggesting that amyloid deposition in insulinoma is due to overproduction of IAPP. Amyloid deposits immunoreactive to IAPP were also seen in all diabetic pancreatic islets, but in no non-diabetic islets. There was much amyloid deposition in the islets of severe diabetics, whose B-cells demonstrated decreased immunoreactivities for IAPP and insulin. The IAPP content of the pancreas was 649.0 and 847.7 pg/mg wet weight in each of two diabetic patients, and 1034.6 and 1447.7 pg/mg wet weight in two non-diabetic patients. The present study revealed that IAPP is a bioactive peptide secreted from islet B-cells and are amyloidogenic peptide concerned in diabetogenensis and/or the progression of type-2 diabetes mellitus.
淀粉样蛋白沉积是胰岛素瘤以及2型糖尿病患者胰腺胰岛中的常见病理特征。目前的免疫组织化学研究显示，正常B细胞、胰岛素瘤以及胰岛素瘤和糖尿病胰腺胰岛中的淀粉样蛋白沉积物，通常与人胰岛淀粉样多肽（IAPP）（24 - 37）的C端合成十四肽抗血清发生免疫反应。胰岛素瘤中的淀粉样纤维通过免疫电子显微镜检查对IAPP也呈阳性。通过放射免疫测定法在一名胰岛素瘤患者的血浆和组织中检测到高水平的IAPP，这表明胰岛素瘤中的淀粉样蛋白沉积是由于IAPP的过度产生。在所有糖尿病胰腺胰岛中也可见到对IAPP呈免疫反应的淀粉样蛋白沉积物，但在非糖尿病胰岛中未见。重度糖尿病患者的胰岛中有大量淀粉样蛋白沉积，其B细胞对IAPP和胰岛素的免疫反应性降低。两名糖尿病患者胰腺的IAPP含量分别为649.0和847.7 pg/mg湿重，两名非糖尿病患者为1034.6和1447.7 pg/mg湿重。本研究表明，IAPP是一种从胰岛B细胞分泌的生物活性肽，是与糖尿病发生和/或2型糖尿病进展有关的淀粉样生成肽。
