血管内皮生长因子和其受体Flt-1在青春期大鼠睾丸、附睾及附睾内精子上的表达研究

Expressions of VEGF and Flt-1 in the Testis,Epididymis and Epididymal Sperm of Adolescent Rats

目的:通过对血管内皮生长因子(VEGF)及其受体Flt-1在大鼠睾丸、附睾及附睾内精子上表达的研究,探讨其在雄性生殖系统中的作用。方法:免疫组化SP法和免疫荧光法检测20只青春期SD大鼠睾丸、附睾及精子上VEGF和Flt-1蛋白的表达情况。结果:VEGF和Flt-1在大鼠睾丸和附睾组织及精子上均有特征性表达。睾丸内VEGF蛋白表达于生精细胞、精子细胞发育中的顶体、Sertoli和Leydig细胞胞质内;Flt-1只见于精子细胞发育中的顶体及Leydig细胞胞质中。附睾中VEGF表达于各段上皮主细胞胞质内,而Flt-1表达于头、尾段上皮主细胞胞质内,体部免疫染色阴性;两者在附睾上皮亮细胞、晕细胞和基细胞中均为阴性表达。免疫荧光染色显示,VEGF和Flt-1共同定位于附睾内精子头部的顶体,尾部的颈、中和主段。结论:VEGF和Flt-1蛋白在大鼠睾丸、附睾及精子中的特异性表达提示,他们可由不同生精上皮细胞、间质细胞和附睾主细胞产生,可能以自分泌或旁分泌的形式单独或共同作用于睾丸和附睾的生殖细胞或Leydig细胞,直接或间接地影响精子的发生、发育和成熟过程,并与精子的活动和受精能力有关。

Objective ： To study the expressions of the vascular endothelial growth factor （VEGF） and its receptor fins-like tyrosine ki- nase-1 （Flt-1） in the testis, epididymis and epididymal sperm of adolescent rats and explore the functions of both the proteins in the male reproductive system. Methods ： The expressions of VEGF and Flt-1 were detected in 20 adolescent SD rats, immunohistochemi- cal staining used for both the testis and the epididymis and immunofluorescent staining for sperm. Results ： VEGF and Flt-1 proteins were specifically present in the testis, epididymis and sperm. In the testis, VEGF immunoreactive particles were localized in the cyto- plasm of spermatogenic cells, the developing acrosome of spermatids, Sertoli ceils and Leydig cells, while Flt-1 expressed mainly in the developing acrosome of spermatids and Leydig cells. In the epididymis, the cell-specific and region-specific expressions of VEGF and Flt-1 proteins were observed in the principal cells of epididymal epithelia, VEGF in the whole epididymis, while Fh-1 only in the caput and eauda segments. Both VEGF and Flt-I were localized in the acrosome of the sperm head as well as in the neck, middle and princi- pal segments of the sperm tail. Conclusion ： The specific expression patterns of VEGF and Flt-I in the rat testis, epididymis and sperm indicate that they may independently or collectively affect spermatogenesis and spermiotelcosis in either an autocrinological or a paracrinological way. Natl J Androl , 2008, 14 （10） ： 871-875