Effects of castration and late hormonal replacement in the structure of rat corpora cavernosa.

The objective of the study was to evaluate, through quantitative methods, the structural alterations in the corpora cavernosa of rats submitted to orchiectomy as well as the role of late hormone replacement in overturning the possible structural alterations. Twenty-five male rats were assigned into 5 groups with 5 animals each and treated as follows: ORCHIEC-1 = submitted to orchiectomy and sacrificed after 1 month; C-1 = control group sacrificed after 1 month; ORCHIEC-2 = submitted to orchiectomy and sacrificed after 2 months; C-2 = control group sacrificed after 2 months; and T = submitted to orchiectomy, underwent testosterone replacement with testosterone undecanoate (100 mg/kg) after 1 month, and sacrificed after 1 month of hormonal replacement. Smooth muscle, collagen, and elastic system fibers of penile corpora cavernosa were quantified. There was a significant decrease in the absolute values of smooth muscle, sinusoidal space, and total area of corpora cavernosa after 2 months in the castrated group when compared with controls. Overall, regarding density, no significant differences were observed among the groups. The hormonal replacement with testosterone was able to reverse the alterations observed. The method used for this research allowed demonstrating that absolute values are reliable to quantify the structural alterations of corpora cavernosa structures. The results suggest that hormonal replacement, even when instituted at a late stage, is effective in reversing the corpora cavernosa's structural alterations produced by castration.