College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungbuk National University, 410 Seongbongro (Gaeshin-dong), Cheongju, Chungbuk 361-763, Republic of Korea.
Biol Pharm Bull. 2010;33(2):273-8. doi: 10.1248/bpb.33.273.
The effects of a silk amino acid (SAA) preparation on the physical stamina and male reproductive function of mice were investigated. Eight-week-old male ICR mice (29-31 g) were orally administered SAA (50, 160 or 500 mg/kg) for 44 d during 30-min daily swimming exercise. The mice were subjected to a weight-loaded (5% of body weight) forced swimming on the 14th, 28th and 42nd day to determine maximum swimming time, and after a 2-d recovery period (treated with SAA without swimming exercise), parameters related to fatigue and reproductive function were analyzed from blood, muscles and reproductive organs. Repeated swimming exercise increased the maximum swimming time to some extent, in spite of a marked reduction in body weight gain, and SAA further enhanced the stamina in a dose-dependent manner. Forced swimming exercises increased blood parameters of tissue injury, but depleted blood glucose and tissue glycogen, which were substantially prevented by SAA treatment. In addition, SAA significantly reduced the muscular thiobarbituric acid-reactive substances and blood corticosterone content increased by forced swimming. Swimming exercise decreased the blood testosterone level, which was recovered by SAA, leading to enhanced sperm counts. These combined results indicate that SAA not only enhances physical stamina by minimizing damage to tissues, including muscles, as well as preventing energy depletion caused by swimming stress, but also improves male reproductive function by increasing testosterone and sperm counts.
本研究旨在探讨丝氨酸氨基酸（SAA）制剂对小鼠体力和生殖功能的影响。选用 8 周龄雄性 ICR 小鼠（体重 29-31g），每天进行 30min 游泳运动并灌胃给予 SAA（50、160 或 500mg/kg）44d。在第 14、28 和 42 天，对小鼠进行负重（体重的 5%）力竭游泳实验以检测最大游泳时间，经过 2d 的恢复期（不进行游泳运动但给予 SAA 处理），从血液、肌肉和生殖器官中分析与疲劳和生殖功能相关的参数。重复游泳运动在一定程度上增加了最大游泳时间，尽管体重增加明显减少，但 SAA 以剂量依赖性方式进一步增强了体力。力竭游泳运动增加了血液组织损伤的参数，但耗尽了血糖和组织糖原，而 SAA 处理显著阻止了这一现象。此外，SAA 还显著降低了游泳运动引起的肌肉丙二醛含量和血液皮质酮含量的增加。游泳运动降低了血液中的睾酮水平，而 SAA 恢复了这一水平，导致精子计数增加。这些综合结果表明，SAA 通过最小化包括肌肉在内的组织损伤以及防止游泳应激引起的能量耗竭来增强体力，同时通过增加睾酮和精子计数来改善雄性生殖功能。
