Department of Physiology, Faculty of Veterinary Medicine, Zagazig University, 44519 Zagazig, Egypt.
Department of Physiology, Faculty of Veterinary Medicine, Zagazig University, 44519 Zagazig, Egypt.
Theriogenology. 2019 Jul 15;133:87-96. doi: 10.1016/j.theriogenology.2019.04.035. Epub 2019 May 1.
Aerobic exercises are considered as an effective method of improving several undesirable health outcomes; however, their implications in the male reproductive axis have remained controversial. The present study evaluated the impact of physical exercise on the male reproductive system in rats and investigated the potential central and peripheral mechanisms involved in it. Twenty male Sprague-Dawley rats were randomly divided into control and exercise groups, with 10 rats per group. The rats were subjected to a swimming exercise for 60 min/day for five days a week and the protocol was followed for six constitutive weeks. We found that the swimming exercise significantly decreased the testicular weight and the testicular somatic index. Furthermore, there was a marked reduction in several sperm characteristics, including sperm count, motility, morphology, and viability in the exercised rats. The serum levels of reproductive hormones, i.e., testosterone (T), luteinizing hormone (LH), and follicle stimulating hormone (FSH) were significantly decreased. A histological examination of testes and epididymis revealed defective spermatogenesis. Molecular analysis revealed the downregulation of the expression of mRNAs of the hypothalamic kisspeptin (Kiss1), Kiss1 receptor (Kiss1r), gonadotropin-releasing hormone (GnRH1), GnRH1 receptor (GnRHr), and testicular Kiss1r along with an upregulation in the gene expression of GnRHr in the pituitary. We also observed a significant reduction in the activity and the expression of mRNAs of testicular superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) and a marked elevation in the levelsof malondialdehyde (MDA). These findings implied that chronic swimming exercise suppressed the Kisspeptin-GnRH signaling pathway, consequently reducing the production of male reproductive hormones. A simultaneous increase in the oxidative stress could contribute to exercise-induced inhibition of male reproductive functions. To conclude, an appropriate training program is important to maximize the benefits and minimize the side effects of physical exercises on the male reproductive system.
有氧运动被认为是改善多种不良健康结果的有效方法；然而，其对男性生殖轴的影响仍存在争议。本研究评估了运动对雄性大鼠生殖系统的影响，并研究了其中涉及的潜在中枢和外周机制。20 只雄性 Sprague-Dawley 大鼠随机分为对照组和运动组，每组 10 只。大鼠每天进行 60 分钟的游泳运动，每周 5 天，持续 6 周。我们发现，游泳运动显著降低了睾丸重量和睾丸体指数。此外，运动大鼠的精子特征，包括精子计数、活力、形态和活力，都有明显下降。血清生殖激素水平，即睾酮（T）、促黄体生成素（LH）和促卵泡激素（FSH）显著降低。睾丸和附睾的组织学检查显示精子发生缺陷。分子分析显示下丘脑 kisspeptin（Kiss1）、Kiss1 受体（Kiss1r）、促性腺激素释放激素（GnRH1）、GnRH1 受体（GnRHr）和睾丸 Kiss1r 的 mRNA 表达下调，同时垂体 GnRHr 的基因表达上调。我们还观察到睾丸超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和谷胱甘肽过氧化物酶（GPx）的活性和 mRNA 表达显著降低，丙二醛（MDA）水平显著升高。这些发现表明，慢性游泳运动抑制了 Kisspeptin-GnRH 信号通路，从而减少了雄性生殖激素的产生。同时，氧化应激的增加可能导致运动引起的雄性生殖功能抑制。总之，适当的训练计划对于最大限度地提高有氧运动对男性生殖系统的益处和最小化其副作用非常重要。
