Dopamine promotes colonic mucus secretion through dopamine D5 receptor in rats
Dopamine promotes colonic mucus secretion through dopamine D5 receptor in rats
复制标题
多巴胺通过多巴胺D5受体促进大鼠结肠粘液分泌
DOI：
10.1152/ajpcell.00261.2017
复制
发表时间：
2019-03-01
影响因子：
5.5
通讯作者：
Zhu, Jin-Xia
中科院分区：
文献类型：
--
作者：
Li, Yun;Zhang, Yue;Zhu, Jin-Xia
Dopamine regulates gastrointestinal mucosal barrier. Mucus plays important roles in the protection of intestinal mucosa. Here, the regulatory effect of dopamine on rat colonic mucus secretion was investigated. RT-PCR, immunofluorescence, Periodic Acid-Schiff reagent assay, Alcian blue-Periodic Acid-Schiff staining, and enzyme-linked immunosorbent assay were used to observe the expression of dopamine receptor and the direct effect of dopamine on the colonic mucus. Mice injected intraperitoneally with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) destroying enteric dopamine (DA) neurons, rats microinjected with 6-hydroxydopamine (6-OHDA) into the bilateral substantia nigra damaging central dopaminergic neurons, and dopamine D-5 receptor-downregulated transgenic mice were used to detect the effect of endogenous enteric dopamine or dopamine receptors on distal colonic mucus. Our results indicated that D-5 immunoreactivity was widely distributed on the colonic goblet cells. Dopamine dose-dependently increased rat distal colonic mucus secretion in vitro. D1-like receptor antagonist SCH23390 inhibited dopamine (1 mu M)-induced distal colonic mucus secretion. D1-like receptor agonist SKF38393 promoted mucin 2 (MUC2) secretion and increased the intracellular cAMP level of colonic mucosa. D-5 receptor- \downregulated transgenic mice showed a decreased colonic MUC2 content. MPTP-treated mice exhibited lower colonic dopamine content and decreased colonic mucus content. 6-OHDA rats had an increase in the dopamine content in colonic mucosa but decreases in the protein levels of D-1 and D-5 receptors and MUC2 content in the colonic mucosa. These findings reveal that dopamine is able to promote distal colonic mucus secretion through the D-5 receptor, which provides important evidence to better understand the possible role of dopamine in the colonic mucosal barrier.
