胸腺小体在胸腺发育中的形态发生及其功能探讨

用组织化学与免疫组织化学技术对8例人胎(胎龄16～32周)的胸腺进行研究,观察在其发育过程中胸腺小体的形态变化及增殖细胞核抗原(Proliferating Cell Nuclear Antigen,PCNA)、花生凝集素(Peanut Aggulutinin,PNA)和细胞角蛋白(Cytokeratin,CK)等的表达特征.结果显示:胸腺小体是在胸腺发育阶段由胸腺上皮细胞呈同心圆状排列而成,且胎儿胸腺中单个和融合状的胸腺小体都较成体胸腺中明显增多.围成胸腺小体的上皮细胞从周边向中央,角蛋白含量明显减少,增殖能力逐渐减弱,表现为逐渐退化的过程.证实胸腺小体是处理退变的上皮细胞的场所.另外,在胸腺小体的上皮细胞膜有PNA受体的表达,这提示在胸腺的发育成熟过程中,胸腺小体上皮细胞与胸腺细胞之间可能存在着相互识别相互诱导的作用.

MORPHOGENESIS AND FUNCTIONAL DIFFERENTIATION OF THYMIC CORPUSCLES DURING THE DEVELOPMENT OF FETAL THYMUS

Thymus specimens of 8 human fetuses from 16 to 32 weeks were studied histochemically with Methylgreen-Pyronine staining and immunohistochemically with monoclonal antibodies ( anti-PCNA, cytokeratin and PNA) by ABC method. The result showed that the thymic corpuslces Vere formed by thymic epithelial cells in concentric circles on melted together. The expressions of PCNA, PNA and cytokeratin in the thymic corpuscles indicated that the degenerating cells were dealt within the corpuscles, and that the thymic epithelial cells and the thymic cells might be recognized and induced each other during the developing of thymus.