The effect of testosterone replacement therapy on bladder functions and histology in orchiectomized mature male rats

To investigate the effect of testosterone replacement therapy on bladder functions and smooth muscle/collagen content in orchidectomized orchiectomized mature male rats.

The study included 25 mature male Sprague-Dawley rats divided into 3 groups. After bilateral orchiectomy, 8 rats received intramuscular saline injection, as a control group, and 8 rats received intramuscular injection of testosterone undecanoate 100 mg/kg as a treatment group. The sham group had 9 rats. Urodynamic studies were performed in all groups, before and after the study. The rats were killed after 60 days, and cystometric findings and smooth muscle/collagen ratio of the bladders were compared between the groups.

From the beginning to the end of the experiment, mean maximal bladder capacity increased 46.61% +/- 20.82 in the testosterone treatment group, while decreased 38.91% +/- 17.83 in control group, revealing a significant difference (P = .002). Smooth muscle/collagen ratio was significantly higher in the testosterone treatment group (1.53 +/- .34) than in the control group (1.05 +/- .32), (P = .01).

This study showed that bladder capacity and smooth muscle/collagen content improved with testosterone therapy in orchiectomized rats. Therefore, testosterone replacement therapy in late-onset hypogonadal men with urogenital dysfunction may have a positive role to improve bladder function by increasing bladder smooth muscle.