给予睾酮会抑制大鼠出生后发育最早阶段的生精小管生长起始，并减少支持细胞数量。

Walczak-Jedrzejowska Renata, Słowikowska-Hilczer Jolanta, Marchlewska Katarzyna, Oszukowska Elzbieta, Kula Krzysztof

Department of Andrology, Medical University of Lodz, Poland.

Folia Histochem Cytobiol. 2009;47(5):S149-54. doi: 10.2478/v10042-009-0094-z.

UNLABELLED

Sertoli cell (SC) number determines testes size and their capacity to produce spermatozoa. In the rat SC proliferate until 15th postnatal day (PND). Their proliferation is stimulated by FSH and inhibited by estradiol, but the role for androgens is uncertain. In this study we analyzed the effects of testosterone administration on testes growth and SC number in relation to timing of the treatment. Male rats were injected with 2.5 mg of testosterone propionate (TP) from birth until 5th PND and autopsied either on 6th PND [TP1-5(6)] or on 16th PND [TP1-5(16)] (transient administration). Other rats received TP from birth until 15th PND [TP1-15] or between 5th and 15th PND [TP5-15] continuously and were autopsied on day 16th. Control groups (C) received vehicle. In the Cs serum level of estradiol was 20-fold higher (p<0.001) and FSH was 1,7-fold higher (p<0.05) on 6th PND than on 16th PND, while testosterone did not change. After TP blood level of testosterone increased 2200-fold on 6th PND (p<0.05), and 8-fold on 16th PND. In turn, continuous TP administrations resulted on 16th PND in the increase in testosterone serum level by 2000-times of C without influence on FSH. While the treatment from birth either during initial 5 days or continuously until 15th day decreased testicular weight (p<0.001), tubule length (p<0.05) and SC number (p<0.001), the treatment initiated on 5th PND had no effects. TP reduced serum estradiol level on 6th PND by 13-fold (p<0.01), but doubled it on 16th PND.

CONCLUSION

Neonatal rats secrete estradiol and FSH in the amounts greatly extending those presented during further development. Testosterone inhibits testicular growth and SC number acting during first 5 neonatal days by decreasing FSH secretion, but is not effective during further development. Direct inhibitory influence of testosterone or trough its increased aromatisation to estradiol beyond neonatal period may be responsible for sustained inhibition of testes growth and SC number during infancy.

未标记

支持细胞（SC）数量决定睾丸大小及其产生精子的能力。在大鼠中，支持细胞在出生后第15天（PND）前增殖。它们的增殖受促卵泡激素（FSH）刺激，受雌二醇抑制，但雄激素的作用尚不确定。在本研究中，我们分析了睾酮给药时间对睾丸生长和支持细胞数量的影响。雄性大鼠从出生至第5天PND注射2.5mg丙酸睾酮（TP），并分别在第6天PND [TP1 - 5(6)]或第16天PND [TP1 - 5(16)]进行解剖（短暂给药）。其他大鼠从出生至第15天PND [TP1 - 15]或在第5天至第15天PND [TP5 - 15]持续接受TP，并在第16天进行解剖。对照组（C）接受溶剂。在对照组中，第6天PND时雌二醇血清水平比第16天PND高20倍（p<0.001），FSH高1.7倍（p<0.05），而睾酮无变化。TP给药后，第6天PND时睾酮血水平增加2200倍（p<0.05），第16天PND时增加8倍。反过来，持续TP给药使第16天PND时睾酮血清水平比对照组增加2000倍，而对FSH无影响。虽然从出生开始在最初5天内或持续至第15天的治疗会降低睾丸重量（p<0.001）、小管长度（p<0.05）和支持细胞数量（p<0.001），但在第5天PND开始的治疗没有效果。TP使第6天PND时血清雌二醇水平降低13倍（p<0.01），但在第16天PND时使其翻倍。