Samir Haney, Nyametease Paul, Nagaoka Kentaro, Watanabe Gen
Laboratory of Veterinary Physiology, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan; Department of Theriogenology, Faculty of Veterinary Medicine, Cairo University, Giza 12211, Egypt.
Laboratory of Veterinary Physiology, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan; Department of Animal Science, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana.
Anim Reprod Sci. 2018 Oct;197:185-192. doi: 10.1016/j.anireprosci.2018.08.027. Epub 2018 Aug 23.
The objectives of this study were to determine if there is a seasonal pattern of testicular blood flow in male Shiba goats, and ascertaining whether or not there is a relationship among changes in testicular hemodynamics and circulating testosterone (T) and estradiol (E2). Twelve sexually mature male Shiba goats (Capra hircus), aged 19.5 ± 2.5 months were used in this study. Monitoring of the changes in testicular blood flow was performed once a week for 1 year, using color spectral Doppler ultrasonography. Plasma concentrations of testosterone (T) and estradiol (E2) were determined by radioimmunoassay. Among the four seasons, the greatest increases (P ≤ 0. 001) in the values for the resistive index (RI) and pulsatility index (PI) of the testicular artery were recorded in the summer. Also, PI and RI values recorded in spring were greater than those recorded in autumn, while for winter there were the least values for these indices. Likewise, concentrations of T and E2 showed seasonal changes. Concentrations of T and E2 were greater during the autumn and winter compared to those in spring and summer. Interestingly, E2 concentrations were negatively associated with Doppler indices of the testicular artery. In conclusion, although Shiba goats are considered to be non-seasonal breeding animals, there were distinct seasonal patterns of testicular blood flow as measured by color Doppler ultrasonography, especially in Doppler indices. These changes were coincident with the changes in the circulating E2 and may be attributable to the seasonal changes in ambient temperature or daylight length.
本研究的目的是确定雄性柴山羊睾丸血流是否存在季节性模式，并确定睾丸血流动力学变化与循环睾酮（T）和雌二醇（E2）之间是否存在关系。本研究使用了12只性成熟的雄性柴山羊（Capra hircus），年龄为19.5±2.5个月。使用彩色频谱多普勒超声，每周对睾丸血流变化进行一次监测，持续1年。通过放射免疫测定法测定血浆睾酮（T）和雌二醇（E2）的浓度。在四个季节中，睾丸动脉阻力指数（RI）和搏动指数（PI）的值在夏季增幅最大（P≤0.001）。此外，春季记录的PI和RI值大于秋季，而冬季这些指数的值最小。同样，T和E2的浓度也呈现季节性变化。与春季和夏季相比，秋季和冬季T和E2的浓度更高。有趣的是，E2浓度与睾丸动脉的多普勒指数呈负相关。总之，尽管柴山羊被认为是非季节性繁殖动物，但通过彩色多普勒超声测量发现，睾丸血流存在明显的季节性模式，尤其是在多普勒指数方面。这些变化与循环E2的变化一致，可能归因于环境温度或日照长度的季节性变化。
