Department of Gerontology, Sixth People's Hospital affiliated to Shanghai Jiaotong University, Shanghai, China.
Am J Med Sci. 2011 Jul;342(1):38-43. doi: 10.1097/MAJ.0b013e31820f835b.
The objective of this study is to investigate the effects of androgen on renal sodium excretion and renal functional in sodium-loaded rats.
Sixty male Wistar rats aged 8 weeks were used, of which 48 underwent orchiectomy and the other 12 underwent a sham procedure. The 48 orchiectomized rats were randomly divided into 4 groups (12/group): castrated rats (Cas), testosterone-supplemented castrated rats (TC), flutamide (androgen receptor blocker)-treated castrated rats (FC) and flutamide-treated testosterone-supplemented castrated rats (FTC). The 12 sham-operated rats served as controls. All 60 rats were fed with 8% NaCl chow for 8 weeks. Systemic blood pressure (BP) was recorded at 0, 4 and 8 weeks. Sodium excretion, microalbuminuria and creatinine clearance were calculated before and at the end of the experiment. Circulating levels of testosterone and angiotensin II and plasma renin activity were measured by radioimmunological method at the end of the experiment.
BP of controls and TC was higher at 8 weeks than at baseline; BP of Cas, FC or FTC was lower than that of controls. Plasma renin activity and angiotensin concentrations were lower in Cas, FC and FTC (groups with testosterone absent or blocked) than in controls and TC (groups with testosterone intact). Cas, FC and FTC displayed less microalbuminuria, higher sodium excretion and higher creatinine clearance than control and TC.
In salt-loaded rats, testosterone seems to activate the renin-angiotensin system, resulting in sodium retention, higher BP and renal injury.
本研究旨在探讨雄激素对钠负荷大鼠肾钠排泄和肾功能的影响。
60 只 8 周龄雄性 Wistar 大鼠，其中 48 只接受去势手术，12 只接受假手术。48 只去势大鼠随机分为 4 组（每组 12 只）：去势大鼠（Cas）、补充睾酮的去势大鼠（TC）、用氟他胺（雄激素受体阻滞剂）处理的去势大鼠（FC）和用氟他胺处理的补充睾酮的去势大鼠（FTC）。12 只假手术大鼠作为对照组。所有 60 只大鼠均给予 8%NaCl 饲料 8 周。分别于 0、4 和 8 周时记录系统血压（BP）。在实验前和实验结束时计算钠排泄量、微量白蛋白尿和肌酐清除率。实验结束时采用放射免疫法测定循环睾酮和血管紧张素 II 水平及血浆肾素活性。
对照组和 TC 组的 BP 在 8 周时高于基线；Cas、FC 或 FTC 组的 BP 低于对照组。在 Cas、FC 和 FTC（无或阻断睾酮）组中，血浆肾素活性和血管紧张素浓度低于对照组和 TC（有完整睾酮）组。Cas、FC 和 FTC 组的微量白蛋白尿减少、钠排泄增加、肌酐清除率升高，均优于对照组和 TC 组。
在盐负荷大鼠中，睾酮似乎激活了肾素-血管紧张素系统，导致钠潴留、血压升高和肾脏损伤。
