Alterações urodinâmicas em camundongos castrados e sua repercussão após reposição hormonal com testosterona

Abstract

The aging process faced by men enables the concomitant emergence of two conditions capable of affecting the normal functioning of the lower urinary tract (LUT), as well as of causing lower urinary tract symptoms (LUTS), namely: benign prostatic hyperplasia (BPH) and androgen deficiency in aging male (DAEM). The role played by testosterone in the LUT remains uncertain. The aim of the current study is to evaluate urodynamic findings in hypogonadal mice subjected to castration, and its outcome after testosterone administration in castrated mice. In total, 24 Black C57BL6 mice were randomized into 3 groups. The Sham group was subjected to incision in the scrotal sac and to testicular exposure; the Orchiectomy group was subjected to surgical castration; and the Orchiectomy + Testosterone group was simultaneously subjected to castration and to exogenous testosterone administration. Parameters such as the number of non-voiding contractions (NVC), Basal Pressure (BP), Pressure Threshold (PT), Bladder Capacity (BC), Urinary Frequency (UF), Bladder Complacency (C) and animal weight were evaluated. Statistical evaluation was performed in the GraphPad Prism software version 7.0, based on analysis of variance (ANOVA) and on Tukey’s test. Data normality distribution was analyzed through the Kolmogorov-Smirnov test. P ≤ 0.05 was statistically significant. The Orchiectomy + Testosterone group showed higher NVC (15.33 ± 5.32) than the Sham (4.29 ± 1.5) (P < 0.01) and Orchiectomy (2.17 ± 0.41) (P < 0.01) groups. The Orchiectomy group presented lower BP (13.5 mmHg ± 4.53) than the Sham (19.99 mmHg ± 1.88) (P = 0.05) and Orchiectomy + Testosterone (17.58 mmHg ± 6.36) groups. The Orchiectomy group presented lower PT (18.91 mmHg ± 3.49) than the Sham (24.71 mmHg ± 2.93) and Orchiectomy + Testosterone (23.34 mmHg ± 6.15) (P = 0.05) groups. BC was also lower in the Orchiectomy group (0.13ml ± 0.04) than in the Sham (0.28ml ± 0.06) (P = 0.03) and Orchiectomy + Testosterone (0.32ml ± 0.16) (P = 0.01) groups. The Orchiectomy + Testosterone group presented higher UF (7.59/min ± 3.26) than the Sham (3.65/min ± 0.51) (P < 0.01) and Orchiectomy (2.63/min ± 0.50) (P < 0.01) groups. Bladder complacency did not show significant differences between groups. Castration reduced all cystometric voiding parameters (NVC, BP, PT, Volume, UF), except for bladder complacency. Exogenous testosterone administration prevented the development of these changes in castrated mice. Keywords: Testosterone. Orchiectomy. LUTS. Hypogonadism.