The effect of testosterone alone and testosterone plus estradiol therapy on bladder functions and smooth muscle/collagen content in surgically menopause induced rats

Objectives: The aim of the study was to investigate the effect of testosterone alone and testosterone + estradiol therapy on bladder functions and smooth muscle/collagen content in surgically menopause induced rat model. Methods: The study included 34 female Sprague-Dawley rats, and the rats were divided into four groups. After bilateral oophorectomy, during a 60 days period, six rats received IM saline injection for one time, as a control group, and nine rats received testosterone undecanoate 100 mg/kg IM for one time, and nine rats received testosterone undecanctate 100 mg/kg IM for one time + daily 0.50 mg nasal spray of 17 beta estractiol. Ten rats were taken as sham group. Urodynamic studies were performed in all groups before and after the study. The rats were sacrificed after 60 days, and cystometric findings and smooth muscle/collagen ratio of the bladders were compared between the groups. Results: Increase in maximal bladder capacity and compliance were significantly higher in the testosterone treatment group and testosterone + estradiol treatment group than in the control group (p = 0.01 and p = 0.002, respectively for bladder capacity; p = 0.04 and p = 0.005, respectively for bladder compliance). Smooth muscle/collagen ratio of the bladders was significantly higher in the testosterone and testosterone + estradiol treatment groups than in the control group (p = 0.04 and p = 0.008, respectively). Conclusions: This study shows that bladder functions may deteriorate in postmenopausal period. In addition to estrogen replacement therapy, testosterone has a significant role to increase bladder smooth muscle, leading to improvement in bladder functions in postmenopausal women with urogenital system dysfunction. (C) 2008 Elsevier Ireland Ltd. All rights reserved.