摘要
目的研究束缚应激导致的内脏高敏感性大鼠回盲部黏膜5-羟色胺(5-HT)含量的变化及替加色罗对应激大鼠回盲部黏膜5-HT含量的影响。方法雄性Wistar大鼠24只,分为对照组、应激组和替加色罗组,采用免疫组化方法观察3组大鼠回盲部黏膜5-HT的分布并作定量分析,应用免疫电镜观察应激组和替加色罗组大鼠回盲部肠上皮嗜铬细胞的5-HT含量。结果应激组大鼠回盲部组织5-HT阳性细胞的吸光度值显著低于对照组大鼠(0·326±0·035比0·362±0·042,P<0·001),替加色罗组大鼠为0·364±0·033,与应激组大鼠比较显著增高(P<0·001),在电镜下胶体金颗粒主要分布于肠嗜铬细胞的分泌颗粒,替加色罗组胶体金阳性的分泌颗粒明显多于应激组。结论应激大鼠肠黏膜5-HT阳性细胞释放5-HT的增加可能是其内脏高敏感性的发生机制之一,替加色罗改善内脏高敏感性的作用是部分通过调节胃肠道5-HT的含量达到的。
Objective To investigate the content and distribution of serotonin in the ileoceal mucosa of rats under partial restraint stress (PRS) and to study the effect of tegaserod on the content of serotonin in the positive cells. Methods Male Wistar rats (n = 24) were divided into three test groups. After shamstress (control group) or PRS had been applied to the rats for two hours, 1-methyl-2-pyrrolidinone (solvent) or tegaserod (a partial 5-HT4 receptor agonist) was administered intra-peritoneally to the corresponding groups. The cellular distribution and quantitative analysis of 5-HT in the ileoceal mucosa were achieved with immunohistochemical method and computerized image system. The 5-HT content of individual enterochromaffin cells (EC) in tegaserod group and PRS group were observed with immunoelectron microscopic technique. Results Serotonin immunoreactivity was mainly found in the epithelium and lamina propria of the mucosa. As compared with the control group, the optical density of serotonin-immunoreactive cells in ileoceal mucosa decreased in the PRS rats(0. 326±0. 035 vs 0. 362±0. 042 ,P 〈0. 001 ) ,the optical density of serotonin-immunoreactive cells in ileoceal mucosa in the tegaserod group (0. 364 ±0. 033 ) was much higher than in the PRS rats ( P 〈 0. 001 ). Immunoelectron microscopic study showed that in the tegaserod group, EC in the epithelium contained more serotonin-positive secretary granules than in the PRS rats. Conclusions The increased 5-HT release of positive cells in gut mucosa may be partly responsible for visceral hypersensitivity. The effect of tegaserod on visceral hypersensitivity, at least in part, is likely to act through the pathway involving regulation of gastrointestinal 5-HT release.
出处
《中华内科杂志》
CAS
CSCD
北大核心
2005年第9期687-689,共3页
Chinese Journal of Internal Medicine