Saito K, O'Donnell L, McLachlan R I, Robertson D M
Department of Urology, Yokahama City University School of Medicine, Kanagawa, Japan.
Endocrinology. 2000 Aug;141(8):2779-85. doi: 10.1210/endo.141.8.7628.
Spermiation is the process by which mature sperm are released from the Sertoli cell into the lumen of the seminiferous tubule. Previous studies have shown that FSH and LH/testosterone suppression causes a significant increase in the degeneration of mature elongated spermatids. The purpose of this study was to investigate the extent to which spermiation failure contributes to the overall failure of spermatogenesis during hormone suppression. We used in vivo models to selectively suppress either FSH, by passive immunization, and or testosterone, by administration of SILASTIC brand (Dow Corning) testosterone and estradiol implants to suppress LH and testicular testosterone production. Stereological quantitation of the number of step 17-18 spermatids before spermiation and the number of step 19 spermatids retained within the epithelium after spermiation showed that 2% of spermatids failed to spermiate in control animals, and 11% and 14% of spermatids failed to spermiate after 1 week of FSH inhibition or testosterone suppression, respectively. After 1 week of combined FSH and testosterone withdrawal, 50% of the spermatids in the testis failed to be released. A time course of testosterone suppression showed that after 4-5 weeks over 90% of spermatids failed to spermiate. We conclude that spermiation is highly sensitive to hormone suppression, with T and FSH acting synergistically to support spermiation, and that spermiation inhibition is a potential target for contraception.
精子释放是指成熟精子从支持细胞释放到生精小管管腔的过程。先前的研究表明，促卵泡激素（FSH）和黄体生成素/睾酮抑制会导致成熟延长型精子细胞的退化显著增加。本研究的目的是调查在激素抑制过程中，精子释放失败对生精过程整体失败的影响程度。我们使用体内模型，通过被动免疫选择性抑制FSH，以及通过植入SILASTIC品牌（道康宁）睾酮和雌二醇植入物来抑制LH和睾丸睾酮生成，从而选择性抑制睾酮。对精子释放前第17 - 18阶段精子细胞数量以及精子释放后上皮内保留的第19阶段精子细胞数量进行体视学定量分析，结果显示，对照动物中有2%的精子细胞未能完成精子释放，在抑制FSH或睾酮1周后，分别有11%和14%的精子细胞未能完成精子释放。在联合停用FSH和睾酮1周后，睾丸中50%的精子细胞未能释放。睾酮抑制的时间进程显示，4 - 5周后超过90%的精子细胞未能完成精子释放。我们得出结论，精子释放对激素抑制高度敏感，睾酮和FSH协同作用支持精子释放，并且抑制精子释放是避孕的一个潜在靶点。
