Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, University of São Paulo, Rua Prof. Orlando Marques de Paiva, 87, São Paulo, 05508-270, Brazil.
Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, University of São Paulo, Rua Prof. Orlando Marques de Paiva, 87, São Paulo, 05508-270, Brazil.
Anim Reprod Sci. 2021 May;228:106745. doi: 10.1016/j.anireprosci.2021.106745. Epub 2021 Mar 22.
Senescence leads to deleterious effects in testicular function, sperm quality and fertility in dogs. There, however, are no consistent results of vascular changes in the testes and epididymis during natural ageing in dogs. The aim of this study, therefore, was to compare testes and epididymis blood flow, biometry and echodensity between young and senile dogs. Ten young dogs (1-4 years) and eight senile dogs (over 7 years) were selected and assigned to two experimental groups: Young Group and Senile Group. Dogs were evaluated using testicular and epididymis B-mode (dimensions and echodensity) and Doppler ultrasonography (tissue perfusion parameters and blood flow velocity of the testicular artery). There were no differences between experimental groups for the echographic evaluation of testicular and epididymis parenchyma and biometric variables. The dogs in the Young Group had greater (P = 0.02) testes vascularization score and greater (P = 0.06) testicular artery blood flow velocity than those in the Senile Group. Furthermore, the older dogs had a greater (P = 0.06) pulsatility index of the testicular artery than those in the Young Group. Ageing, therefore, seems to cause natural hemodynamical changes to the testicular artery, resulting in reduced blood flow (ischemia) and tissue damage. Testes and epididymis vascular characteristics, therefore, may represent the causal factors for changes in spermatogenesis and, as a consequence, negatively affect the sperm quality of older dogs. In conclusion, senescence alters testicular artery blood flow and vascularization of the testes, without changing testicular and epididymis ultrasonographic dimensions and echodensity in dogs.
衰老会导致犬睾丸功能、精子质量和生育能力受损。然而，在犬自然衰老过程中，睾丸和附睾的血管变化并没有一致的结果。因此，本研究旨在比较年轻犬和衰老犬睾丸和附睾的血流、生物测量和回声密度。选择了 10 只年轻犬（1-4 岁）和 8 只衰老犬（7 岁以上），并将它们分为两组：年轻组和衰老组。使用睾丸和附睾 B 型超声（尺寸和回声密度）和多普勒超声（组织灌注参数和睾丸动脉血流速度）对犬进行评估。两组间睾丸和附睾实质及生物测量变量的超声评估无差异。年轻组的犬睾丸血管化评分较高（P = 0.02），睾丸动脉血流速度较快（P = 0.06）。此外，老年犬的睾丸动脉搏动指数也高于年轻组（P = 0.06）。因此，衰老似乎会导致睾丸动脉发生自然血流动力学变化，导致血流减少（缺血）和组织损伤。因此，睾丸和附睾的血管特征可能是精子发生变化的原因，并导致老年犬的精子质量下降。总之，衰老改变了睾丸动脉的血流和睾丸的血管化，而不改变犬的睾丸和附睾的超声尺寸和回声密度。
