Involvement of enterochromaffin (EC) cells in diarrhea

1.产生5 -羟色胺的EC细胞和含有vip的神经广泛分布于消化道，被认为最重要的是参与肠道分泌的调节。双重免疫染色显示细胞与神经密切相关。生理费用；利用犬十二指肠环进行的体内实验支持了以下观点：腹泻是由EC细胞释放的血清素介导的，血清素导致VIP从邻近神经转移；这两个信使既串联工作，又并行工作，增强了彼此的影响。PACAP（垂体腺苷酸环化酶激活多肽）被证明能强烈激活肠上皮中的离子运输。C1^-释放对PACAP的增强作用被证明是通过刺激胆碱能和非胆碱能神经而产生的间接效应。特异性拮抗剂实验表明5-HT_3和5-HT_4是参与肠道分泌的5-羟色胺受体类型。SEA（葡萄球菌肠毒素A），以前被认为会引起严重的呕吐，被证明会导致狗的肠道分泌明显增强（腹泻）；电镜观察发现EC细胞释放的血清素参与其中。

1.Serotonin-producing EC cells and VIP-containing nerves are distributed extensively in the digestive tract and are believed to be most importantly involved in the regulation of intestinal secretion. Double immunostaining demonstrated intimate association of the cells and the nerves.2.Physiological expe ; riments in vivo using canine duodenal loops support the view that diarrhea is mediated by serotonin released from EC cells, which causes liveration of VIP from vicinal nerves ; both messengers working in series as well as in parallel, potentiating the effect of each other.3.PACAP (Pituitary Adenylate Cyclase-Activating Polypeptide) was demonstrated to intensely activate ion transport in the intestinal epithelium. Enhancement by PACAP by C1^- release was shown to be an indirect effect via stimulation of cholinergic and non-cholinergic nerves.4.Experiments using specific antagonists indicated 5-HT_3 and 5-HT_4 as the types of serotonin receptors involved in intestinal secretion.5.SEA (Staphylococeal Enterotoxin A), previously know as causeing severe vomit, was demonstrated to cause a marked enhancement of intestinal secretion (diarrhea) in dogs ; involvement of serotonin released from EC cells was suggested by electron microscope examination of the cells.