Awoniyi C A, Santulli R, Sprando R L, Ewing L L, Zirkin B R
Department of Population Dynamics, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, Maryland 21205.
Endocrinology. 1989 Mar;124(3):1217-23. doi: 10.1210/endo-124-3-1217.
We examined the effect of exogenously administered testosterone (T) on the quantitative restoration of advanced spermatogenic cells in adult rat testes rendered azoospermic by treating rats with polydimethylsiloxane (PDS) implants of T and estradiol (E). Experimental rats received PDS-TE implants for an initial 8-week period; control rats received empty implants. By 8 weeks of PDS-TE treatment, rats became severely oligospermic, and the T concentration within the seminiferous tubule fluid (STF) was reduced approximately 80% (from 57.8 ng/ml in controls to 9.6 ng/ml). After the initial 8-week PDS-TE treatment, PDS-TE implants were removed from one group of rats; a second group of PDS-TE-implanted rats received an additional PDS-T implant of 24 cm. Eight weeks after the removal of PDS-TE implants or the implantation of additional T, testis weight and numbers of advanced spermatogenic cells were restored to those of control rats. The STF T concentration 8 weeks after the removal of PDS-TE implants also was restored to that in control rats. In contrast, the STF T concentration increased to only 40% of control values in the rats that received an additional T implant. Despite this 60% reduction in T concentration compared to the control value, advanced spermatogenic cell number was restored to a value indistinguishable from that of intact controls. These observations indicate that spermatogenesis can be quantitatively restored in PDS-TE-implanted rats with exogenously administered T, and moreover, that this restoration does not require the high T concentration found in the STF of intact control rats.
我们研究了外源性给予睾酮（T）对成年大鼠睾丸中高级生精细胞数量恢复的影响。这些成年大鼠通过植入聚二甲基硅氧烷（PDS）包裹的睾酮（T）和雌二醇（E）而导致无精子症。实验大鼠最初8周接受PDS-TE植入物；对照大鼠接受空植入物。在PDS-TE治疗8周时，大鼠变得严重少精子症，生精小管液（STF）中的T浓度降低了约80%（从对照组的57.8 ng/ml降至9.6 ng/ml）。在最初8周的PDS-TE治疗后，一组大鼠移除PDS-TE植入物；另一组植入PDS-TE的大鼠额外植入了24 cm的PDS-T植入物。移除PDS-TE植入物或额外植入T后8周，睾丸重量和高级生精细胞数量恢复到对照大鼠的水平。移除PDS-TE植入物8周后的STF T浓度也恢复到对照大鼠的水平。相比之下，接受额外T植入物的大鼠中，STF T浓度仅增加到对照值的40%。尽管与对照值相比T浓度降低了60%，但高级生精细胞数量恢复到与完整对照大鼠无法区分的值。这些观察结果表明，外源性给予T可使植入PDS-TE的大鼠生精功能在数量上得以恢复，而且这种恢复并不需要完整对照大鼠STF中所发现的高T浓度。
