The effect of surgical and medical castration on penile erectile tissue: ultrastructural study

BACKGROUND: This study aimed to evaluate the ultrastructural pathophysiological changes in penile erectile tissue caused by surgical and medical castration using light and electron microscopy.METHODS: Sprague-Dawley rats were divided into three groups. Group A underwent bilateral orchiectomy (N.=10), Group B received weekly LHRH agonist injections (N.=10), and Group C (sham-operated control group) served as the control (N.=10). After 4 weeks, all rats were sacrificed, and penile cavernosal tissues were harvested. The ultrastructure of trabecular smooth muscle cells, their relationship with sinus endothelial cells, and the collagen status in the intermediate tissue were examined using an electron microscope. Serum testosterone levels were measured on day 1 and week 4 across all groups.RESULTS: Serum testosterone levels were significantly lower in Groups A and B compared to the control group (30.06; 84.1; 215 ng/dL, respectively) (P<0.001). Tunical thickness was significantly reduced in both Groups A and B compared to the control group (19.00; 26.78; and 48.90 μm, respectively) (P<0.001). Additionally, tunical thickness in the surgical castration group (Group A) was significantly lower than in the medical castration group (Group B) (P<0.001). Ultrastructural analysis revealed atrophy and degeneration in smooth muscle fibers in Groups A and B, as well as disintegration of endothelial and smooth muscle cell connections, increased collagen production, and greater fibrotic changes.CONCLUSIONS: Ultrastructural evaluation demonstrated that testosterone deprivation impairs erectile function by disrupting cavernosal expansion, intercellular coordination, and venous compression, leading to erectile dysfunction.