Pudney J, Lacy D
J Reprod Fertil. 1977 Jan;49(1):5-16. doi: 10.1530/jrf.0.0490005.
Distinct differences in tha ability of isolated seminiferous tubules and interstitium to utilize steroid precursors for androgen production in vitro were observed during the reproductive cycle of the American grey squirrel, Sciurus carolinensis. In spermatogenically active testes, the seminiferous tubules and the interstitium readily synthesized androgens from labelled C21 steroid precursor; seminiferous tubules also produced significant amounts of 17alpha,20alpha-dihydroxyprogesterone. However, during sexual regression androgen synthesis was drastically reduced in both testicular components, while the production of 20alpha-reduced metabolites of progesterone and 17alpha-hydroxyprogesterone was increased. Many of the fine-structural changes occurring in Leydig and Sertoli cells during the reproductive cycle could be correlated with the capacity of isolated seminiferous tubules and interstitium to formulate androgens from labelled precursors.
在美国灰松鼠（Sciurus carolinensis）的繁殖周期中，观察到分离的生精小管和间质在体外利用类固醇前体产生雄激素的能力存在明显差异。在精子发生活跃的睾丸中，生精小管和间质很容易从标记的C21类固醇前体合成雄激素；生精小管还产生大量的17α,20α-二羟孕酮。然而，在性消退期间，两个睾丸成分中的雄激素合成急剧减少，而孕酮和17α-羟孕酮的20α-还原代谢产物的产生增加。在繁殖周期中，莱迪希细胞和支持细胞发生的许多细微结构变化可能与分离的生精小管和间质从标记前体合成雄激素的能力相关。
