胚胎小鼠胃肠道5-羟色胺及生长抑素免疫反应细胞的个体发生

Ontogeny of 5-HT and somatostatin immunoreactive cells in gastrointestinal tract of fetal mouse

目的观察胚胎期小鼠胃肠道内5-羟色胺(5-hydroxytryptamine,5-HT)免疫反应(immunoreactive,IR)细胞和生长抑素(somatostatin,SS)IR细胞的个体发生、分布、形态及数量变化。方法用抗5-HT、抗SS多克隆抗体对胚龄16-19d小鼠胃肠道相邻切片进行染色。结果小鼠胚胎发育第17天,消化道各段即可见5-HT-IR和SS-IR细胞。胚龄17-19d,小鼠十二指肠5-HT-IR细胞的数量明显多于小肠其余段和结肠,而腺胃中5-HT-IR细胞最少。SS-IR细胞的分布和数量变化类似于5-HT-IR细胞。5-HT-IR和SS-IR细胞形态多样,可见阳性染色的细胞突起伸抵腔面或伸至其他细胞之间。结论胚胎期小鼠胃肠道5-HT-IR细胞及SS-IR细胞的发生及数量变化规律有其种属的特异性。这两种内分泌细胞的形态特点为其同时具备外分泌和旁分泌作用提供了形态学依据。

Objective To study the ontogeny,distribution,morphological characteristics and the number changes of 5-hydroxy-tryptamine（5-HT）and somatostatin（SS）immunoreactive（IR）cells in the gastrointestinal tract of embryonic mouse. Methods The gastrointestinal tract sections of mouse embryos from embryonic day 16（ED16）to ED19 were stained with polyclonal antibodies against 5-HT and SS.Results The 5-HT-IR and SS-IR cells were found in mouse gastrointestinal tract at ED 17.At ED17-19,the numbers of 5-HT-IR cells in duodenum were significantly more than that in the remainder of small intestine and the colon,but least in glandular stomach.The distribution and numbers of SS-IR positive cells were similar to that of 5-HT-IR cells.The 5-HT-IR and SS-IR positive cells in gastrointestinal tract were various in shape.Some immunoreactive positive processes were found extending to the lumen or the adjacent cells. Conclusion The ontogeny and the number changes of 5-HT-IR and SS-IR cells in mouse gastrointestinal tract are different from the other species.The morphological characteristics of the two kinds of endocrine cells could provide morphological evidences for verifying that they may have both exocrine and paracrine functions simultaneously.