Mulder H, Lindh A C, Sundler F
Department of Medical Cell Research, University of Lund, Sweden.
Cell Tissue Res. 1993 Dec;274(3):467-74. doi: 10.1007/BF00314543.
The expression of the islet amyloid polypeptide (IAPP) gene within the endocrine pancreas and its correlation with insular neuroendocrine peptide localization were investigated in the rat. In situ hybridization with a 35S-labelled IAPP-mRNA specific oligonucleotide probe was combined with immunocytochemistry. In situ hybridization alone showed strong autoradiographic labelling of the pancreatic islets. In situ hybridization combined with immunocytochemistry for IAPP, revealed labelling of the IAPP-immunoreactive cells. However, when in situ hybridization was combined with immunocytochemistry for proinsulin, we noted a lack of proinsulin immunoreactivity in some peripherally located autoradiographically labelled islet cells. Furthermore, combination of in situ hybridization and immunocytochemistry for somatostatin showed autoradiographic labelling of somatostatin cells to a varying degree. This was further confirmed by showing cellular co-localization of IAPP and somatostatin by immunocytochemical double staining. We conclude that IAPP is mainly synthesized in insulin cells. Additionally, a subpopulation of the somatostatin cells is capable of IAPP synthesis. This may account for the relatively small reduction in the content of IAPP-mRNA in islets compared to the marked reduction of insulin mRNA after streptozotocin-induced diabetes in rats as previously reported.
在大鼠中研究了胰岛淀粉样多肽（IAPP）基因在内分泌胰腺中的表达及其与胰岛神经内分泌肽定位的相关性。用35S标记的IAPP - mRNA特异性寡核苷酸探针进行原位杂交，并结合免疫细胞化学技术。单独的原位杂交显示胰岛有强烈的放射自显影标记。原位杂交与IAPP免疫细胞化学相结合，显示了IAPP免疫反应性细胞的标记。然而，当原位杂交与胰岛素原免疫细胞化学相结合时，我们注意到一些位于外周的放射自显影标记的胰岛细胞缺乏胰岛素原免疫反应性。此外，原位杂交与生长抑素免疫细胞化学相结合显示，生长抑素细胞有不同程度的放射自显影标记。免疫细胞化学双重染色显示IAPP和生长抑素的细胞共定位进一步证实了这一点。我们得出结论，IAPP主要在胰岛素细胞中合成。此外，生长抑素细胞的一个亚群能够合成IAPP。这可能解释了与先前报道的链脲佐菌素诱导的糖尿病大鼠中胰岛素mRNA的显著减少相比，胰岛中IAPP - mRNA含量相对较小的减少。
