Low testosterone levels induce apoptosis via active 3-caspase dependent signaling in the bladder wall of male rats.

OBJECTIVE The bladder can be considered a target organ for testosterone action, and low testosterone levels possibly cause damage to bladder cells. We set out to study whether hypoandrogenism influences bladder wall cell damage in castrated and senile male rats. METHODS Thirty male Wistar rats were divided into three groups of 10 animals each: group I (3 months old), sham animals; group II (27 months old), senile animals; group III (3 months old), subjected to bilateral orchiectomy, and sacrificed 8 weeks after the procedure. Bladders were excised, weighed and sent for analysis. Stereological assays on collagen fibers and immunohistochemical analysis with active 3-caspase were performed on bladder cells. RESULTS Bladder weights were greater in the senile group than in the others. Stereological collagen fiber analysis demonstrated higher density in group III than in groups I and II (p < 0.05). The absolute density was 4.15 mm(3) in group I, 22.3 mm(3) in group II and 19.3 mm(3) in group III. Semiquantitative active 3-caspase analysis showed greater percentages in the senile group II than in groups I and III. CONCLUSIONS We can state that low plasma testosterone levels are related to higher collagen fiber density and active 3-caspase percentages in the bladder walls of orchiectomized and senile rats, respectively.