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.

中文翻译：

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精子发生异常犬睾丸脉搏多普勒搏动及睾丸动脉阻力指数升高

最近使用睾丸动脉的脉冲波多普勒 (PWD) 超声检查来比较可育和不育男性或精液质量正常和异常的男性的参数，而没有研究证实睾丸的伴随组织学特征。本研究的实验假设是，PWD 测量的睾丸动脉不同水平的血流参数反映了对从附睾尾部采集的精子评估的精子属性和睾丸组织学特征。记录了来自 16 只生育能力未知的狗的两个睾丸的脉搏波多普勒参数。常规阉割后，收集附睾精子并评估精子的总和进行性运动、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，以分别量化微观属性和结缔组织和血管面积范围。结果表明，增加的 PWD 指数提示睾丸组织学改变，因为在睾丸边缘动脉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）之间存在负相关（R = -0.528，P = 0.016 和 R = -0.554，分别为 P = 0.005）和管状面积/总面积比（分别为 R = -0.494，P = 0.024 和 R = -0.563，P = 0.004）。一些组织学特征，如肾小管直径、生精上皮厚度、睾丸的管状面积/总面积比与原发性异常的百分比相关（R = -0.874，P = 0.001，R = -0.847，P = 0.001，R = - 0.865，P = 0.001，分别）。在精子原发性异常增加的睾丸中，与睾丸上动脉（1.07 ± 0.06 vs 0.82 ± 0.23，P < 0.05）、边缘动脉（0.73 ± 0.04 vs 0.61 ± 0.07，P < 0.05）的正常精子发生的睾丸相比，发现更高的搏动指数) 和睾丸内动脉 (0.67 ± 0.03 vs 0.43 ± 0.1, P < 0.05)。同样，在精子发生异常和正常的睾丸的相同血管束中，电阻指数显着升高（分别为 0.62 ± 0.02、0.53 ± 0.02 和 0.46 ± 0.02 vs 0.51 ± 0.06、0.44 ± 0.04 和 0.36 ± 0.0. P < 0.05)。我们的数据首次证明了 PWD 指数与上下文睾丸结构之间的关系，表明搏动和阻力指数可能是男科的有效工具。鉴于睾丸的不同组织学改变，在定义正常和异常睾丸血流指数的阈值时需要谨慎。