Bernal-Mañas C M, Cortes S, Morales E, Horn R, Seco-Rovira V, Beltran-Frutos E, Ferrer C, Canteras M, Pastor L M
Department of Cell Biology and Histology, Aging Institute, IMIB, School of Medicine, Regional Campus of International Excellence 'Campus Mare Nostrum', University of Murcia, Murcia, Spain.
Andrologia. 2014 Aug;46(6):672-9. doi: 10.1111/and.12134. Epub 2013 Jul 21.
The ageing testis is associated with germ loss in the seminiferous epithelium and a decrease in spermatogonia proliferation. In this work, we study whether the stages of the seminiferous epithelium cycle and/or the degree of histological tubular degeneration resulting from ageing is related with this decrease in spermatogonia proliferation. Eleven hamsters were used, five aged 6 months and six aged 24 months. In both groups, the proliferative activity was studied by BrdU immunostaining. The number of BrdU-positive and BrdU-negative cells was measured, providing the overall proliferation index in adult and aged testes. The mean number of BrdU-positive cells was also determined for each degree of histological degeneration of seminiferous epithelium, and a spermatogonia proliferation index was obtained for each stage of the seminiferous cycle. Ageing caused an overall decrease in the BrdU-positive cell percentage and a decrease in the number of BrdU-positive cells in the tubular sections with hypospermatogenesis, the sloughing of germ cells and maturation arrest, these changes being similar in both young and old animals. The spermatogonia proliferation index was only seen to be significantly lower in ageing hamster in stages VII-VIII of the seminiferous epithelium cycle. In conclusion, the overall decrease in proliferation observed in aged seminiferous epithelium is correlated with an increase in the number of degenerated sections of the seminiferous tubules, and this decrease is a phenomenon which occurs in specific stages of the seminiferous cycle.
衰老的睾丸与生精上皮中的生殖细胞丢失以及精原细胞增殖减少有关。在本研究中，我们探究生精上皮周期阶段和/或衰老导致的组织学上的小管退化程度是否与精原细胞增殖减少相关。我们使用了11只仓鼠，其中5只为6月龄，6只为24月龄。在两组中，通过BrdU免疫染色研究增殖活性。测量BrdU阳性和BrdU阴性细胞的数量，得出成年和老年睾丸的总体增殖指数。还针对生精上皮的每个组织学退化程度确定BrdU阳性细胞的平均数量，并针对生精周期的每个阶段获得精原细胞增殖指数。衰老导致BrdU阳性细胞百分比总体下降，并且在生精功能低下、生殖细胞脱落和成熟停滞的管状切片中BrdU阳性细胞数量减少，这些变化在年轻和老年动物中相似。仅在生精上皮周期的VII - VIII阶段，衰老仓鼠的精原细胞增殖指数显著降低。总之，在衰老的生精上皮中观察到的增殖总体下降与生精小管退化切片数量的增加相关，并且这种下降是在生精周期的特定阶段出现的一种现象。
