Brito Maíra Morales, Angrimani Daniel de Souza Ramos, Rui Bruno Rogério, Kawai Giulia Kiyomi Vechiato, Losano João Diego Agostini, Vannucchi Camila Infantosi
Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil.
Aging Male. 2020 Dec;23(4):279-286. doi: 10.1080/13685538.2018.1487931. Epub 2018 Jul 11.
The present research aimed to compare the hormonal profile, sperm quality and freezability of young and senile dogs. Dogs were assigned into Young Group ( = 11) and Senile Group ( = 11), additionally divided into Fresh Semen Group and Cryopreserved Semen Group. Males were evaluated for libido score and blood estrogen and testosterone assay. Sperm morphofunctional evaluations were performed based on Computer Assisted Sperm Analysis, morphology, mitochondrial activity, mitochondrial membrane potential, plasma and acrosomal membrane integrity, and DNA fragmentation. Sperm oxidative features were: protein oxidation, lipid peroxidation and production of advanced glycation end-products. Young dogs had higher libido score, sperm velocity average pathway, linearity of motility and mitochondrial activity index and lower percentage of major defects, total defects and proximal cytoplasmic droplet, despite the lack of difference between hormone profile of aged dogs. Fresh semen of senile dogs had increased percentage of spermatozoa with high mitochondrial membrane potential compared to young dogs and to cryopreserved sperm. Cryopreserved semen of young dogs had higher acrosomal membrane integrity compared to the Senile Group. In conclusion, sperm of aged dogs have reduced quality, signaled by higher morphological defects, ultimately altering sperm mitochondrial function and sperm kinetics. Furthermore, spermatozoa from senile dogs are more sensible to cryoinjury.
本研究旨在比较年轻犬和老年犬的激素水平、精子质量及冷冻保存能力。犬只被分为年轻组（n = 11）和老年组（n = 11），每组再进一步分为新鲜精液组和冷冻精液组。对雄性犬只进行性欲评分以及血液雌激素和睾酮检测。基于计算机辅助精子分析、形态学、线粒体活性、线粒体膜电位、质膜和顶体膜完整性以及DNA碎片化等指标进行精子形态功能评估。精子氧化特征包括：蛋白质氧化、脂质过氧化和晚期糖基化终产物的产生。年轻犬具有较高的性欲评分、精子平均运动速度、运动线性度和线粒体活性指数，以及较低的主要缺陷、总缺陷和近端细胞质滴百分比，尽管老年犬的激素水平无差异。与年轻犬及冷冻保存精子相比，老年犬的新鲜精液中具有高线粒体膜电位的精子百分比增加。与老年组相比，年轻犬的冷冻精液具有更高的顶体膜完整性。总之，老年犬的精子质量下降，表现为更高形态学缺陷，最终改变精子线粒体功能和精子动力学。此外，老年犬的精子对冷冻损伤更敏感。
