Functions of serotonin-containing EC cells in the GI tract

胃肠道中含有血清素的 EC 细胞的功能

• 批准号: 07670011
• 负责人: FUJIMIYA Mineko
• 金额: $ 1.34万
• 依托单位: Shiga University of Medical Science
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07670011/
• 关键词: Gastrointestinal; Serotonin; Serotonin Receptor; Motility; Luminal release; Immunoelectron microscopy; クロモグラニンA; 腸管; EC細胞

The functional role of serotonin (5HT)-containing enterochromaffin cells in the gastrointestinal tract has been studied. First of all, we examined the mechanism to regulate the release of 5HT from isolated perfused rat duodenum. Cholinergic muscarinic mechanism stimulated the release of 5HT into the intestinal lumen. CCK stimulated the release of 5HT into the lumen, this mechanism was mediated by the cholinergic mechanism. VIP and PACAP inhibited the release of 5HT into the lumen via the VIP-2 receptors on the EC cells. VIP/PACAPs and NO were strongly related on the inhibition of 5HT release. To examine the functional role of 5HT released from the EC cells, the effect of 5HT receptor antagonists on the intestinal motility was investigated. 5HT-3 receptor antagonist strongly blocked the duodenal motility. 5HT-4 receptor antagonist weekly blocked, however 5HT-1 or-2 receptor antagonist did not change the motility. Finally, we examined the change in the intracellular localization of 5HT after stimulation of luminal release of 5HT by immunoelectron microscopy. Since we obtained the evidence that the luminal release of 5HT was stimulated by the high intraluminal pressure, the isolated perfused duodenum was exposed to the high luminal pressure, fixed and prepared for immunoelectron microscopic study. Immunogold particles which react to 5HT were concentrated over the secretory granules in normal conditions, however they diffusely scattered over the extragranular cytoplasm and over the microvilli in the stimulated duodenum. These results suggest that 5HT might be diffusely released from the EC cells to the intestinal lumen by a diacrine manner of secretion.

含5-羟色胺(5-羟色胺)的肠嗜铬细胞在胃肠道中的功能作用已被研究。首先，我们研究了大鼠十二指肠离体液中5-羟色胺释放的调节机制。胆碱能毒碱机制刺激5-羟色胺向肠腔内释放。CCK通过胆碱能机制促进5-羟色胺向管腔内释放。VIP和PACAP通过EC细胞上的VIP-2受体抑制5-羟色胺的释放。VIP/PACAPs和NO对5-羟色胺释放的抑制作用密切相关。为探讨内皮细胞释放5-羟色胺的功能作用，本实验观察了5-羟色胺受体拮抗剂对肠动力的影响。5HT3受体拮抗剂对十二指肠运动有强烈的阻断作用。5-羟色胺-4受体拮抗剂每周阻断，而5-羟色胺-1或-2受体拮抗剂不改变运动。最后，我们用免疫电子显微镜观察了5-羟色胺腔内释放刺激后5-羟色胺在细胞内定位的变化。由于我们获得了高腔内压刺激5-羟色胺释放的证据，所以我们将分离的灌流十二指肠暴露在高腔压下，固定并准备免疫电子显微镜研究。正常情况下，与5-羟色胺反应的免疫金颗粒主要集中在分泌颗粒上，而在受刺激的十二指肠中则弥漫分布在颗粒外细胞质和微绒毛上。这些结果提示，5-羟色胺可能以一种双分泌方式从EC细胞向肠腔内扩散释放。

项目成果

藤宮 峯子, 奥宮 清人: "EC細胞におけるセロトニンの外分泌-免疫電顕的研究-" 消化管ホルモン(XV). 15. 33-38 (1997)

Mineko Fujimiya、Kiyoto Okumiya：“EC 细胞中血清素的外分泌分泌 - 免疫电子显微镜研究”胃肠激素 (XV) 15. 33-38 (1997)。

K.Okumiya, K.Matsubayashi, T.Maeda, M.Fujimiya: "Change in subcellular localization of gastrin-like immunoreactivity in epithelial cells of rat duodenum induced by carbachol" Peptides. 17. 225-232 (1996)

K.Okumiya、K.Matsubayashi、T.Maeda、M.Fujimiya：“卡巴胆碱诱导的大鼠十二指肠上皮细胞胃泌素样免疫反应性亚细胞定位的变化”肽。

M.Fujimiya,K.Okumiya,A.Kuwahara: "Immunoelectron microscopic study for luminal release of serotonin from rat enterochromaffin cells induced by high intraluminal pressure" Histochemistry and Cell Biology. (in press). (1997)

M.Fujimiya、K.Okumiya、A.Kuwahara：“高腔内压力​​诱导的大鼠肠嗜铬细胞腔内释放血清素的免疫电子显微镜研究”组织化学和细胞生物学。

M.Fujimiya, K.Okumiya, A.Kuwahara: "Immunoelectron microscopic study of luminal release of serotonin from rat enterochromaffin cells induced by high intraluminal pressure" Histochemistry and Cell Biology. 108. 105-113 (1997)

M.Fujimiya、K.Okumiya、A.Kuwahara：“高腔内压力​​诱导的大鼠肠嗜铬细胞腔内释放血清素的免疫电子显微镜研究”组织化学和细胞生物学。

M.Fujimiya, K.Okumiya, A.Kuwahara: "Immunoelectron microscopic study of luminal release of serotonin from rat enterochromattin cells induced by high intraluminal pressure" Histochemistry and Cell Biology. 108. 105-113 (1997)

M.Fujimiya、K.Okumiya、A.Kuwahara：“高腔内压力​​诱导的大鼠肠染色质细胞释放血清素的免疫电子显微镜研究”组织化学和细胞生物学。