人胎睾丸的组织发生

HISTOGENESIS OF THE HUMAN TESTES

用7~38周人胎35例,取睾丸固定于Carnoy液,石蜡包埋,以HE、PAS反应及甲绿哌喏宁法染色。7周初的性腺尚未分化,可见散在的原始生殖细胞。13周睾丸特征已明显,白膜厚,睾丸素清楚,索间有密集的嗜酸性间质细胞。14.5周部分睾丸索出现小腔,而成管状。睾丸索包含大而着色淡的原始生殖细胞及色深的原始支持细胞。胎早期原始生殖细胞含有丰富的糖原颗粒。睾丸门、白膜及表面上皮内均见散在或成群的生殖细胞。睾丸间质细胞分幼稚型、成熟型及退化型。13~15周以幼稚型为主;16~18周以成熟型为主,成熟型的胞质内含有RNA颗粒;20周后退化型增多,成熟型减少。38周时,睾丸间质细胞单个或成行存在,数量大为减少。

Testes of 35 human fetuses from 7-week gestation to newborn were studied.The testes were fixed in Carnoy’s solution and stained with HE,Unna’s method for RNA and McManus PAS reaction for glycogen.In 7-week old embryo(CRL 18mm),the gonad shows no morphological indication of sex,and still is indifferentiated.In the 13-week embryo,the basic structural of the testis such as thickened fibrous tunica albuginea,prominent sex cords and accumulative interstitial cells are clearly identifiable.The sex cords are now called testicular cords which were composed of primordial germ cells and supporting cells.The cords lumen appeared at 14.5-week of gestation and the germ cells in the cords are distinguished by the size of cell bodies,contain-ing a large amount of glycogen and large round nuclei with conspicuous nucleoli.The eosinophil accumulative interstitial cell(Leydig cell)may be divided into 3 types:inmature,mature and degenerating.In the 20-week embryo the number of the interstitial cells decreased sharply.