Huh Jung Sik, Chung Byung Ha, Hong Chang Hee, Ryu Ji Kan, Kim Jang Hwan, Han Woong Kyu, Park Kyung Kgi
Department of Urology, Jeju National University Hospital, Jeju National University, Jeju, South Korea.
Department of Urology, Gangnam Severance Hospital, Yonsei University Health system, Seoul, South Korea.
Int J Impot Res. 2018 Jun;30(3):122-128. doi: 10.1038/s41443-017-0010-6. Epub 2018 May 4.
Short periods of testosterone suppression have been shown to reduce trabecular smooth muscle content and increase interstitial connective tissue accumulation in animal models. However, the long-term effects of testosterone suppression remain unclear. The aim of this study was to evaluate the long-term effects of testosterone suppression on penile structure and erectile function in rats. Subjects were divided into two groups by observation period (short-period group (group I), 12 weeks; long-period group (group II), 20 weeks). Each group comprised three different subgroups (10 rats each): sham-operated control, surgical castration, and testosterone replacement (4 weeks after an 8-week castration period). Group II subgroups included a sham control, surgical castration, and testosterone replacement (4 weeks after a 16-week castration period). Erectile function was assessed by measuring intracavernosal pressure in response to cavernous nerve stimulation, and expression of the endothelial nitric oxide synthase (eNOS) protein was determined by western blot analysis. Serum testosterone values were measured via radioimmunoassay. The results indicated that serum testosterone level, penile length and girth, cavernosal smooth muscle content, and eNOS activity decreased significantly in castrated animals. These effects were rescued by testosterone undecanoate injection. Erectile function was normalized over 4 weeks in rats that received androgen replacement. Expression of eNOS was decreased in the corpus cavernosum of castrated animals compared with controls, while androgen replacement normalized the expression of eNOS. These results were consistently observed regardless of the duration of androgen deprivation. Thus, these data suggest that androgen regulates the expression of eNOS in the rat penile corpus cavernosum and confirm the importance of androgens in the maintenance of erectile function. Additionally, long-term androgen deprivation does not induce irreversible structural or erectile functional changes in sexually mature adult male rats.
在动物模型中，短期睾酮抑制已被证明可减少小梁平滑肌含量并增加间质结缔组织积聚。然而，睾酮抑制的长期影响仍不清楚。本研究的目的是评估睾酮抑制对大鼠阴茎结构和勃起功能的长期影响。根据观察期将受试者分为两组（短期组（I组），12周；长期组（II组），20周）。每组包括三个不同的亚组（每组10只大鼠）：假手术对照组、手术去势组和睾酮替代组（去势8周后4周）。II组亚组包括假手术对照组、手术去势组和睾酮替代组（去势16周后4周）。通过测量海绵体神经刺激后海绵体内压评估勃起功能，并通过蛋白质印迹分析测定内皮型一氧化氮合酶（eNOS）蛋白的表达。通过放射免疫测定法测量血清睾酮值。结果表明，去势动物的血清睾酮水平、阴茎长度和周长、海绵体平滑肌含量和eNOS活性显著降低。十一酸睾酮注射可挽救这些影响。接受雄激素替代的大鼠在4周内勃起功能恢复正常。与对照组相比，去势动物海绵体中eNOS的表达降低，而雄激素替代使eNOS的表达恢复正常。无论雄激素剥夺的持续时间如何，均一致观察到这些结果。因此，这些数据表明雄激素调节大鼠阴茎海绵体中eNOS的表达，并证实雄激素在维持勃起功能中的重要性。此外，长期雄激素剥夺不会在性成熟的成年雄性大鼠中诱导不可逆的结构或勃起功能改变。
