Recognition of Fatty acids by Gastw intestinal hormone producing cells.

由于脂肪酸可以刺激小肠中大部分胃肠道肽的释放，因此肠内分泌细胞中可能存在一个共同的脂肪酸识别系统。也就是说，在十二指肠中添加脂肪酸会使胰腺向十二指肠分泌的胰酶增加。具有甲基化羧基的三种脂肪酸（油酸、亚油酸和亚麻酸）没有产生这种反应。辛酸（一种短碳链脂肪酸）也没有。在选择脂肪酸作为理想食物时，也观察到对脂肪酸的相同特异性。我们假设肠细胞，包括肠内分泌细胞和舌头上的味蕾，会有一个共同的系统来识别脂肪酸。我们发现受体蛋白参与肠上皮细胞的脂肪感觉机制，以及原本在脂肪组织中表达的脂肪酸结合蛋白（FAT）在空肠上皮细胞刷状缘的选择性表达。免疫染色显示，对脂肪的免疫反应性特异性地定位于味蕾细胞的顶端部分。上述结果提示，味觉细胞中存在类似于肠上皮的膳食脂肪检测系统，脂肪参与了常见的脂肪酸感觉机制。

Since fatty acids stimulate the release of most of the gastrointestinal peptides from the small intestine, a common system for the recognition of fatty acids is likely to exist in enteroendocrine cells. That is, administering fatty acids in the duodenum produced an elevation in pancreatic enzyme secretion from the pancreas into duodenum. The three (oleic, linoleic, and linolenic) fatty acids with methylated carboxyl groups, did not produce this response. Neither did caprylic acid, a fatty acid with a short carbon chain. The same specificity against the fatty acids was observed in the fatty acid selection as desirable foods. We have hypothesized that enterocytes, including enteroendocrine cells and taste buds in the tongue, would have a common system for recognizing fatty acid.We found that the participation of receptor protein in the fat-sensory mechanism of intestinal epithelial cells, and selective expression of fatty-acid binding protein (FAT), originally expressed in adipose tissue, in the brush border of jejunal epithelial cells. Immunological stsaining revealed that immunoreactivity for FAT is specifically localized in the apical part of taste bud cells. These findings suggested that some dietary fat detecting system similar to that in the intestinal epithelium exists in taste cells, and that FAT participates in the common fatty-acid sensory mechanisms.