P物质、血管活性肠肽和乙酰胆碱能神经在大鼠肠道内的分布及其关系

应用乙酰胆碱酯酶(AChE)组织化学和PAP免疫组织化学方法,比较观察P物质(SP)、血管活性肠肽(VIP)和AChE三种阳性神经元在大鼠十二指肠、空肠、回肠、结肠和直肠内的分布特征及其相互关系。结果显示:SP、VIP、AChE阳性神经神经元和纤维均分布于肠壁各层,从十二指肠、空肠到回肠逐渐增多,但从结肠到直肠则逐渐减少;AChE阳性神经元或纤维在肠壁各层最丰富,其中VIP以粘膜层和粘膜下神经丛较丰富,SP以肠肌丛较丰富;三者的分布密度为AChE>VIP>SP。AChE、SP和VIP阳性神经元胞体及神经纤维在不同肠段的分布密度有明显差异(P<0.05),提示可能与不同肠段肠动力调节功能有关。

Distribution and relationship of substance P, vasoactive intestinal polypeptide and cholinergic neurons in the intestinal tract of rat

A comparative study on the distribution and relationship of substance P (SP) ,vnsoactive intestinal polypeptide(rIP) and ace-tylcholinesterase (ACHE)-positive neurons in duodenum, jejunum, ileum, colon and rectum of rats was conducted by enzyme histoehemi-cal and peroxidnse-antiperoxidase (PAP) method. The resalts showed that SP-, VIP-and AChE-positive neurons and fibers were widely distributed in all laminae of intestinal tract of rat, displaying a distribution pattern of progressive increase in density from duodenum, jeju-num to ileum, and gradual reduction from colon to rectum. Abundant ACHE-positive neurons/fibers were observed across the laminae of intestinal tract, moderate density of VIP-and SP-positive nerves/neurons were observed in the mucnsa/submucosa and in Auerbach's my-enteric plexus (AMP), respectively. Statistics showed that the AChE-positive fibers were the highest in density, followed by VIP-pnsitive structures and SP-positive structures were the least in density. The significant difference in density of ACHE-, SP-and VlP-pnsitive neu-rons/fibers in different segments of intestinal tract might be related to the regulation of motility of intestine at different segments of intestinal tract.