Histopathological Changes in Penile Cavernousal Tissue and Tunica Albuginea in Rats after Medical and Surgical Castration and Their Role in the Mechanism of Erectile Dysfunction

Objective: Demonstration of histopathological changes in penile tissue due toandrogen deficiency should bring a better comprehension of the mechanisms of erectiledysfunction and provide a possibility for appropriate treatment modalities.The aim of our study was determination of both the histological changes in corpuscavernosum, tunica albuginea and subtunical area, and their reversibility withtestosterone undecanoate replacement after surgical and medical castration in rats.Materials and Methods: Rats were divided into seven groups as medicallycastrated (A and C), surgically castrated (B and C), sham (E), exogenous testosteronewithout castration (F) and controle (G) groups. Groups A and B were given testosteronereplacement (i.m. testosterone undecanoate). Leuprolide acetate was used for medicalcastration of groups A and C. Tissues of sacrified rats were examined by light andelectron microscope. In addition, histomorphometric analysis was used to compare thethicknesses of tunica albugineas of all the groups.Results: Serum testosterone levels of surgically and medically castrated ratsreturned to physiological levels after replacement therapy.Penile tissues from castrated groups histopathologically showed an increase inkollagen, infrequency and damaged smooth muscles, narrowed venous sinuses,apoptosis, thinner tunica albuginea, adipocyte accumulation in subtunical area, but nonof these changes were seen in replacement groups.Conclusion: The histological changes in penile tissues caused by testosteronedeficiency due to testicular, hipothalamo-hypophyseal gonadal system, systemicdiseases and aging, have a basic role in ethiopathogenesis of erectile dysfunction. Ifthese changes are known to be prevented or reversed by testosterone replacement, thistheraphy can be used more consciously for a wider spectrum of diseases. Besides,testosterone replacement may be an alternative theraphy for veno-occlusive disease andvascular insufficiency.This study differs from the others in the literature with having both the medicaland surgical castration groups as well as replacement groups together, and i.m.testosterone undecanoate replacement after madical castration of rats with leuprolideacetate is a novel experimental model.