University of Teramo, Faculty of Veterinary Medicine, Località Piano D'Accio, 64100, Teramo, Italy.
University of Teramo, Faculty of Biosciences and Technologies for Agriculture Food and Environment, Via R. Balzarini 1, 64100, Teramo, Italy.
Theriogenology. 2020 Dec;158:454-460. doi: 10.1016/j.theriogenology.2020.10.015. Epub 2020 Oct 8.
Pulse-wave Doppler (PWD) ultrasonography of the testicular artery was recently used to compare parameters in fertile and infertile males, or males with normal and abnormal semen quality, while no studies verified the concomitant histological feature of the testis. The experimental hypothesis of the present study was that the blood flow parameters measured by PWD at different levels of the testicular artery reflect sperm attributes evaluated on spermatozoa collected from the tail of the epididymis and testicular histological characteristics. Pulse-wave Doppler parameters were recorded on both testes from 16 dogs of unknown fertility. After routine castration, epididymal spermatozoa were collected and evaluated for sperm total and progressive motility, membrane integrity, and sperm morphology. Testes were submitted to histological and immunohistochemical evaluations to quantify microscopic attributes and connective tissue and vascular area extent, respectively. The findings showed that the increased PWD indexes were suggestive of testicular histological alteration since negative correlations were found between pulsatility index and resistive index, measured in the marginal testicular artery, and histological attributes such as the seminiferous epithelial thickness (R = -0.528, P = 0.016 and R = -0.554, P = 0.005, respectively) and the tubular area/total area ratio (R = -0.494, P = 0.024 and R = -0.563, P = 0.004, respectively). Some histological characteristics, such as tubular diameter, seminiferous epithelium thickness, and the tubular area/total area ratio of the testis are correlated with the percentage of primary abnormalities (R = -0.874, P = 0.001, and R = -0.847, P = 0.001, and R = - 0.865, P = 0.001, respectively). In testes with increased sperm primary abnormalities, higher pulsatility index was found compared with testes with normal spermatogenesis in supratesticular artery (1.07 ± 0.06 vs 0.82 ± 0.23, P < 0.05), marginal artery (0.73 ± 0.04 vs 0.61 ± 0.07, P < 0.05), and intratesticular artery (0.67 ± 0.03 vs 0.43 ± 0.1, P < 0.05). Similarly, the resistive index was found significantly higher in the same vessel tracts in testes with abnormal and normal spermatogenesis (0.62 ± 0.02, 0.53 ± 0.02, and 0.46 ± 0.02 vs 0.51 ± 0.06, 0.44 ± 0.04, and 0.32 ± 0.06, respectively; P < 0.05). Our data demonstrated for the first time the relationship between PWD indexes and the contextual testicular architecture, suggesting that the pulsatility and resistive indexes could be an effective tool in andrology. In light of different histological alterations in the testis, caution is warranted in the definition of thresholds for normal and abnormal testicular blood flow indexes.
最近，使用脉冲波多普勒（PWD）超声检查睾丸动脉，以比较有生育能力和不育男性、或精液质量正常和异常男性的参数，而没有研究验证睾丸的伴随组织学特征。本研究的实验假设是，在睾丸动脉的不同水平测量的 PWD 血流参数反映了从附睾尾部收集的精子的精子属性和睾丸组织学特征。对 16 只未知生育能力的狗的两只睾丸进行了 PWD 参数记录。常规去势后，从附睾中收集精子并评估精子总活力和前向运动、膜完整性和精子形态。对睾丸进行组织学和免疫组织化学评估，分别量化微观属性和结缔组织及血管面积比例。研究结果表明，由于在边缘睾丸动脉中测量的搏动指数和阻力指数与组织学属性（如生精上皮厚度（R = -0.528，P = 0.016 和 R = -0.554，P = 0.005）和管状区域/总面积比（R = -0.494，P = 0.024 和 R = -0.563，P = 0.004）呈负相关，因此增加的 PWD 指数提示睾丸组织学改变。一些组织学特征，如管状直径、生精上皮厚度和睾丸的管状区域/总面积比与原发性异常的百分比相关（R = -0.874，P = 0.001，和 R = -0.847，P = 0.001，和 R = -0.865，P = 0.001）。在原发性精子异常增加的睾丸中，与睾丸精子发生正常的睾丸相比，在睾丸上动脉（1.07 ± 0.06 比 0.82 ± 0.23，P < 0.05）、边缘动脉（0.73 ± 0.04 比 0.61 ± 0.07，P < 0.05）和睾丸内动脉（0.67 ± 0.03 比 0.43 ± 0.1，P < 0.05）中发现较高的搏动指数。同样，在睾丸动脉的同一血管中，异常和正常精子发生的阻力指数也显著升高（0.62 ± 0.02、0.53 ± 0.02 和 0.46 ± 0.02 比 0.51 ± 0.06、0.44 ± 0.04 和 0.32 ± 0.06，P < 0.05）。我们的数据首次证明了 PWD 指数与睾丸结构的关系，表明搏动指数和阻力指数可能是男科的有效工具。鉴于睾丸组织学的不同改变，在定义正常和异常睾丸血流指数的阈值时应谨慎。
