极北鲵肠内5-羟色胺、胃泌素和生长抑素内分泌细胞胚后发育

Postembryonic development of endocrine cells producing 5-HT,gastrin and somatostatin in the intestine of Salamandrella keyserlingii

目的观察极北鲵胚后发育期间肠内5-羟色胺(5-HT)、胃泌素(gastrin,GAS)和生长抑素(somatostatin,SS)3种内分泌细胞的分布、形态和数量变化。方法应用亲和素-生物素复合物(avidin-biotin complex,ABC)法免疫组织化学技术,对38-46期健康极北鲵肠内5-羟色胺(5-HT)、胃泌素(GAS)和生长抑素(SS)细胞进行染色,并统计分析不同时期极北鲵肠内3种内分泌细胞的密度。结果 5-HT免疫反应阳性细胞和GAS免疫反应阳性细胞最先在41期检出,而SS免疫反应阳性细胞在42期才检测到。5-HT细胞在41期最少,46期最多,呈年龄相关的递增趋势;GAS细胞在43期最少,44期最多,呈先减后增变化趋势;SS细胞在43期密度高于其它各时期。5-HT细胞最先分布在上皮基部,GAS细胞和SS细胞最先在肠上皮之间检测到。细胞形态多样,有椭圆形、三角形和锥体形等,但以锥体形为主。结论极北鲵胚后不同发育时期肠内3种内分泌细胞的形态与其个体生理活动的改变相适应,且在数量变化上有其种属特异性。

Objective To observe the changes of distribution, morphology and quantity of three types of endocrine cells secre-ting 5-hydroxy tryptamine （5-HT）, gastrin （GAS） and somatostatin （SS） respectively in the intestine of Salamandrella keyserlingii dur-ing postembrtonic development. Methods The cells secreting 5-HT, GAS and SS in the intestines of healthy Salamandrella keyserlingii larvae at 38th-46th stages were stained by Avidin-biotin complex （ABC） immunohistochemical method, and the densities of these three types of endocrine cells were statistically analyzed at different developmental periods. Results The 5-HT and GAS positive cells were first found in the small intestine at the 41st stage while the SS positive cells were detected at the 42nd stage; the quantity of 5-HT cells was minimum at the 41st stage and maximum at the 46th stage, increasing with the age; the number of GAS cells first decreased and then increased, reaching the minimum at the 43rd stage and maximum at the 44th stage; the density of SS cells was higher at the 43rd stage than all other stages. The 5-HT cells were first observed in the basal part of the epithelium, while the GAS and SS cells were ini-tially detected between the epithelium. The cells were found in various shapes, most being cone-shape, some ellipse and some triangle. Conclusion The morphology of the three types of endocrine cells in the intestines of Salamandrella keyserlingii larvae is adaptive to the alteration of individual physiological functions at different developmental stages, and the change of cell number is species-specific.