促性腺激素释放激素拮抗剂对大鼠睾丸支持细胞雄激素受体和Fas配体基因表达的影响

本实验利用注射促性腺激素释放激素拮抗剂（ＧｎＲＨ Ａ）引起睾丸生精细胞程序化死亡的大鼠模型，用地高辛标记的大鼠雄激素受体和Ｆａｓ配体的ＲＮＡ探针对大鼠睾丸石蜡切片进行原位杂交，观察雄激素受体和Ｆａｓ配体基因在生精细胞凋亡中的变化。结果显示，ＧｎＲＨ Ａ处理后曲细精管有退行性变，原位杂交表明此时Ｓｅｒｔｏｌｉ细胞的雄激素受体表达明显减低，而Ｆａｓ配体表达显著升高。提示Ｆａｓ配体的表达可能与生精上皮细胞程序化死亡关系密切。

Effect of gonadotrophin releasing hormone antagonist on androgen receptor and Fas ligand gene expression in rat testis

  Objectives: To study androgen receptor (AR) and Fas ligand (FasL) gene expression during the course of apoptosis of Sertoli cells.Methods: Adult male Sprague Dawley rats were given daily injections of Nal Glu GnRH A (1mg/kg body weight). The testes were removed on days 0(control), 2 and 5.Ten μm of paraffin embedded sections were subjected to in situ hybridization with the digoxin labeled RNA probes.Results: (1) In normal rat testis: the Sertoli cells showed abundant AR mRNA, particularly during stage VII and VIII of spermatocyte. FasL mRNA was detectable only in Sertoli cells. (2) After treatment with GnRH A: The degeneration of seminiferous epithilium occurred on day 5 of treatment. AR gene expression decreased significantly from day 2 of treatment. Fas L gene expression was also affected by GnRH A and showed a time course increase.Conclusion: The gene expression of FasL in rat Sertoli cells increased greatly during the course of apoptosis. Since the seminiferous epithelium was highly proliferative, many pathways of apoptosis during spermatogenesis were regulated by Sertoli cells, our results imply that FasL expression in Sertoli cells may induce the death of nearby spermatocytes.