Thyroid hormones are important in the development and regulation of testes. This study was conducted to determine the effects of hyper- and hypothyroidism on testicular development in prepubertal rats aged 20-70 days. Weaning male rats (20 days old) until day 70 age were randomly divided into four groups: control, hyperthyroid (hyper-T), hypothyroid (hypo-T) and hypothyroid treated with thyroxine (T4) (hypo-T+T4). The results indicated that thyroid hormones caused a significant effect in body and testis weights, and food and water consumption. In addition there were changes in serum concentrations of tri-iodothyronine, T4, thyroid stimulating hormone (TSH) and testosterone. Histomorphology showed a significant decrease in seminiferous tubule diameter in hyper-T compared to the other groups. Leydig cell numbers showed a significant elevation in hyper-T but not in hypo-T groups. Immunostaining indicated that TSH receptor (TSHR), thyroid hormone receptors α/β (TRαβ) and proliferating cell nuclear antigen (PCNA) have the roles in testicular development. Our findings suggest that hyper- and hypo-thyroidism regulate testicular cell proliferation and spermatogenesis in prepubertal rats, indicating that expression of TSHR, TRαβ and PCNA may be regulated by thyroid hormones that are involved in testicular development; and that the administration of T4 to the hypo-T+T4 group leads to an improvement in the testicular condition.

中文翻译：

---

甲状腺功能亢进和甲状腺功能减退对青春期前睾丸细胞发育和增殖的影响。

甲状腺激素在睾丸的发育和调节中很重要。进行这项研究以确定甲亢和甲状腺功能减退对20-70天龄青春期前大鼠睾丸发育的影响。断奶的雄性大鼠（20天大）至70岁，随机分为四组：对照组，甲状腺功能亢进（hyper-T），甲状腺功能减退（hypo-T）和甲状腺素（T4）治疗的甲状腺功能减退（hypo-T + T4）。结果表明，甲状腺激素对人体和睾丸的重量以及食物和水的消耗有显着影响。此外，血清三碘甲状腺素，T4，甲状腺刺激激素（TSH）和睾丸激素的含量也发生了变化。组织形态学显示，与其他组相比，hyper-T中曲细精管直径显着减小。睾丸间质细胞数目在hyper-T组中显着升高，但在hypo-T组中则没有。免疫染色表明，TSH受体（TSHR），甲状腺激素受体α/β（TRαβ）和增殖细胞核抗原（PCNA）在睾丸发育中起作用。我们的研究结果表明，甲状腺功能亢进和甲状腺功能减退调节青春期前睾丸细胞的增殖和精子生成，表明TSHR，TRαβ和PCNA的表达可能受参与睾丸发育的甲状腺激素的调节。并且将T4给予hypo-T + T4组可改善睾丸状况。我们的研究结果表明，甲状腺功能亢进和甲状腺功能减退调节青春期前睾丸细胞的增殖和精子生成，表明TSHR，TRαβ和PCNA的表达可能受参与睾丸发育的甲状腺激素的调节。并且将T4给予hypo-T + T4组可改善睾丸状况。我们的研究结果表明，甲状腺功能亢进和甲状腺功能减退调节青春期前睾丸细胞的增殖和精子生成，表明TSHR，TRαβ和PCNA的表达可能受参与睾丸发育的甲状腺激素的调节。并且将T4给予hypo-T + T4组可改善睾丸状况。