Brubaker P L, Vranic M
Department of Physiology, University of Toronto, Ontario.
Endocr Res. 1987;13(3):229-41. doi: 10.1080/07435808709035455.
The presence of cells containing glucagon-like immunoreactive (GLI) peptides was demonstrated in a rat ileal epithelial cell line (IEC-18) by both immunofluorescence and radioimmunoassay. When cell extracts were subjected to gel filtration chromatography, the cells were found to contain 3.5 Kd glucagon in addition to significant quantities of large molecular weight GLI peptides (apparent molecular weights of 4, 6, 8 and 10 Kd) and a 9 Kd peptide with apparent glucagon immunoreactivity. This was in contrast to extracts of adult rat ileum, which contained only large molecular weight GLI peptides (apparent molecular weights of 6 and 12 Kd). Production of GLI peptides by the IEC-18 cells was stimulated by glucose (p less than 0.02) and inhibited by insulin (p less than 0.01). In conclusion, these results demonstrate that the IEC-18 cells produce both GLI peptides and glucagon, and thus support the notion that proglucagon processing is cell-specific. IEC-18 cells may therefore provide a tool for investigations of some aspects of GLI peptide and glucagon synthesis.
通过免疫荧光和放射免疫测定法，在大鼠回肠上皮细胞系（IEC-18）中证实了含有胰高血糖素样免疫反应性（GLI）肽的细胞的存在。当对细胞提取物进行凝胶过滤层析时，发现这些细胞除了含有大量的大分子GLI肽（表观分子量分别为4、6、8和10 kDa）和一种具有明显胰高血糖素免疫反应性的9 kDa肽外，还含有3.5 kDa的胰高血糖素。这与成年大鼠回肠提取物形成对比，后者仅含有大分子GLI肽（表观分子量为6和12 kDa）。IEC-18细胞产生GLI肽受到葡萄糖刺激（p<0.02），并受到胰岛素抑制（p<0.01）。总之，这些结果表明IEC-18细胞既产生GLI肽又产生胰高血糖素，因此支持了胰高血糖素原加工是细胞特异性的观点。因此，IEC-18细胞可能为研究GLI肽和胰高血糖素合成的某些方面提供一种工具。
