Tesi Matteo, Lazzarini Giulia, Magliaro Chiara, Abramo Francesca, Fanelli Diana, Miragliotta Vincenzo, Rota Alessandra
Department of Veterinary Sciences, University of Pisa, Italy.
Department of Veterinary Sciences, University of Pisa, Italy.
Anim Reprod Sci. 2020 Aug;219:106534. doi: 10.1016/j.anireprosci.2020.106534. Epub 2020 Jun 30.
There are age-related changes in testicular anatomy and physiology whereby there are modifications of sperm production and reproductive hormone functions. Effects of age on testicular microanatomy are well documented in humans, while there is limited understanding of these changes in dogs. The aim of this study was to evaluate age-related changes of seminiferous tubule morphology, interstitial fibrosis and spermatogenesis in dogs. Dogs (n = 32) were divided into four age groups: peripubertal (n = eight), relatively younger (n = seven), reproductively mature (n = seven) and relatively older (n = ten). Picrosirius Red stained sections were used for morphometrical analysis of testicular tissues, while the characteristics of seminiferous epithelium were assessed using a modified Johnsen scoring system for haematoxylin and eosin stained sections. Seminiferous epithelium and seminiferous tubule area increased from peripuberty to reproductive maturity, indicating there were changes during sexual maturation and subsequently there were decreases with further aging. There was a similar age-related trend for changes in seminiferous epithelium height with values being greatest in reproductively mature dogs; while there were no age-related differences in tubular diameter. Collagen content in the testicular interstitium gradually decreased from peripuberty to the age when dogs were reproductively mature and there were subsequent increases in relatively older dogs, thus, there was an association between the extent of testicular fibrosis and senescence. There was a decrease in spermatogenetic functions from relatively younger to older ages. Further investigations are warranted to establish mechanisms responsible for age-related changes of testicular morphology and related clinical implications.
睾丸的解剖结构和生理机能会随着年龄发生变化，精子生成和生殖激素功能也会随之改变。年龄对睾丸微观解剖结构的影响在人类中有充分的记录，但对犬类的这些变化了解有限。本研究的目的是评估犬类生精小管形态、间质纤维化和精子发生的年龄相关变化。将32只犬分为四个年龄组：青春期前（n = 8）、相对年轻（n = 7）、生殖成熟（n = 7）和相对年长（n = 10）。使用天狼星红染色切片对睾丸组织进行形态计量分析，同时使用改良的约翰森评分系统对苏木精和伊红染色切片评估生精上皮的特征。从青春期前到生殖成熟，生精上皮和生精小管面积增加，表明性成熟期间存在变化，随后随着年龄进一步增长而减少。生精上皮高度变化也有类似的年龄相关趋势，在生殖成熟的犬中值最大；而管径没有年龄相关差异。睾丸间质中的胶原蛋白含量从青春期前到犬生殖成熟时逐渐降低，在相对年长的犬中随后增加，因此，睾丸纤维化程度与衰老之间存在关联。从相对年轻到年长，精子发生功能下降。有必要进行进一步研究以确定导致睾丸形态年龄相关变化的机制及其相关临床意义。
