蝘蜓消化管内分泌细胞的免疫组织化学定位

摘要

Objective To clarify the types, regional distributional and distributional density as well as morphological features of gastrointestinal (GI) endocrine cells in the digestive tract (DT) of a reptilian, Sphenomorphus indicus. Methods Using the immunohistochemical streptavidin-peroxidase (S-P)method. Results Five types of endocrine cells, namely 5-hydroxytryptamine (5-HT), somatostatin(SS), gastrin (GAS), substance P (SP) and glucagon (GLU) immunoreactive (IR) cells, were identified in the DT of S. indicus . 5-HT-IR cells, which were most commonly found in the pylorus, distributed throughout the DT at various densities. SS-IR cells were only found in the stomach, GAS-IR only in pylorus and duodenum, GLU-IR only in ileum and rectum, and SP-IR only in the rectum. The endocrine cells were round, oval, fusiform cuneiform, conical or irregular in shape. Most were found in the gastric glands of the stomach and in the epithelium of oesophagus and intestine. Conclusion The regional distribution and relative frequency of IR cells inS. indicus are similar to those of other Reptilia. However,some characteristic differences are observed in this species.%目的阐明爬行动物蝘蜓消化管各段内分泌细胞的类型、局部分布、分布密度和形态学特征.方法应用免疫组织化学技术中链霉卵白素-过氧化物酶(S-P)法.结果在蝘蜓消化管内鉴别出5种内分泌细胞,即:5-羟色胺(5-hydroxytryptamine,5-HT)、生长抑素(somatostatin,SS)、胃泌素(gastrin,GAS)、高血糖素(glucagon,GLU)、P-物质(substance P,SP)免疫活性(immnoreactive,IR)细胞.5-羟色胺免疫活性细胞是消化管中最主要的内分泌细胞类型,以不同密度分布于消化管各段,其中胃幽门部位分布密度最高.生长抑素免疫活性细胞在消化管内仅局限分布于胃部.胃泌素免疫活性细胞仅见于幽门和十二指肠部位.高血糖素免疫活性细胞仅分布于回肠和直肠.P-物质免疫活性细胞仅出现在直肠部位.螺蜓消化管内分泌细胞形态多样:圆形、椭圆形、纺锤形、梭形、楔形、锥形以及不规则形.胃部多数内分泌细胞分布于胃腺中,食管和肠管中多数内分泌细胞则分布于上皮细胞间.结论堰蜓和其它爬行动物胃肠内分泌细胞的分布存在一定共同特征,然而也存在着一些特有的差异.