MAINTENANCE OF ADVANCED SPERMATOGENIC CELLS IN THE ADULT-RAT TESTIS - QUANTITATIVE RELATIONSHIP TO TESTOSTERONE CONCENTRATION WITHIN THE TESTIS
MAINTENANCE OF ADVANCED SPERMATOGENIC CELLS IN THE ADULT-RAT TESTIS - QUANTITATIVE RELATIONSHIP TO TESTOSTERONE CONCENTRATION WITHIN THE TESTIS
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DOI：
10.1210/endo-124-6-3043
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发表时间：
1989-06-01
期刊：
影响因子：
4.8
通讯作者：
EWING, LL
中科院分区：
文献类型：
--
作者：
ZIRKIN, BR;SANTULLI, R;EWING, LL
本文所描述的研究旨在检查大鼠生精管内是否存在维持精子发生所需的睾酮(T)阈值浓度，或者，睾丸内T浓度与维持精子发生之间是否存在剂量-反应关系。通过聚二甲基硅氧烷缓释胶囊给完整的成年雄性大鼠注射T，以在生精小管内以明确的浓度夹住T。植入体积增大的T填充胶囊后，血清、间质和生精小管液(STF)中T浓度呈线性增加。我们研究了睾丸内T浓度的阶跃降低对睾丸维持2个月的高级生精细胞数量的影响。尽管STF T浓度降低了80%(至.apprx)，但在数量上仍保持了完全的精子发生。13 ng/ml)。睾丸维持完全生精的能力对进一步降低STF-T浓度非常敏感。因此，将STF T的浓度从大约13 ng/ml降低到9 ng/ml，导致维持在睾丸中的高级精子细胞的数量减少了大约100倍。106.将STF-T浓度降低到约4 ng/ml时，每个睾丸的高级精子细胞数进一步减少100倍。106.综上所述，这些数据支持这样的观点，即正常大鼠睾丸曲细精管中存在的T远远超过维持正常生精所需的数量，并首次揭示了STF T浓度与大鼠睾丸高级生精细胞的定量维持之间存在剂量-反应关系。
The studies described herein were designed to examine whether there is a threshold concentration of testosterone (T) within the seminiferous tubules that is required to maintain spermatogenesis in the rat, or alternatively, whether there is a dose-response relationship between the intratesticular T concentration and the maintenance of spermatogenesis. T was administered to intact adult male rats via sustained release polydimethylsiloxane capsules in order to experimentally clamp T at well defined concentrations within the seminiferous tubules. Implantation of T-filled capsules of increasing sizes resulted in linear increases in T concentrations in serum, interstitial fluid, and seminiferous tubule fluid (STF). We examined the effect of step decreases in intratesticular T concentrations on the numbers of advanced spermatogenic cells maintained by the testis over a 2-month period. Quantitatively complete spermatogenesis was maintained despite an 80% reduction in the STF T concentration (to .apprx. 13 ng/ml) from control values. The ability of the testis to maintain complete spermatogenesis was extremely sensitive to further decreases in STF T concentration. Thus, reduction of the STF T concentration from approximately 13 to 9 ng/ml resulted in a reduction in the number of advanced spermatids that were maintained in the testis by approximately 100 .times. 106. Reduction of the STF T concentration to approximately 4 ng/ml resulted in a further reduction in the number of advanced spermatids per testis by 100 .times. 106. Taken together, these data support the contention that there is far more T present within the seminiferous tubules of intact rat testes than is required to maintain quantitatively normal spermatogenesis and reveal for the first time that there is a dose-response relationship between the STF T concentration and the quantitative maintenance of advanced sperematogenic cells in the rat testis.