Effect of Tadalafil on Testicular Histology and Sperm Parameters in An Experimental Varicocele Model

Objectives Varicocele is a common cause of male infertility, often associated with oxidative stress and impaired testicular blood flow. This study aimed to evaluate whether orally administered tadalafil, through its cGMP‐mediated vasodilatory and antioxidant effects, can protect against histological damage and altered sperm parameters in a rat model of experimental left varicocele. Methods Twenty‐four male rats were assigned to three groups: control‐sham (Group 1), left varicocele (Group 2), and left varicocele with daily oral tadalafil administration (Group 3; 1 mg/kg/day by oral gavage). After 75 days, left testicular tissues were harvested for histopathological and apoptotic analysis, and sperm samples were collected from left epididymal tissues. Histopathological evaluation was conducted using the modified Johnsen score, and apoptosis was assessed by the apoptotic index. Sperm count, motility, acrosomal defects, and morphological defects were also analyzed. Results In our study, Group 2 (varicocele) showed significantly lower modified Johnsen scores ( p = 0.005) and sperm motility ( p = 0.042), and a higher apoptotic index ( p < 0.001) compared to Group 1 (control‐sham). Compared to Group 2, tadalafil treatment in Group 3 significantly improved sperm motility ( p < 0.001) and reduced the apoptotic index ( p = 0.004), while the increase in Johnsen score was not statistically significant ( p = 0.140). The thickness of the tunica media layer was significantly higher in Groups 2 ( p = 0.008) and 3 ( p = 0.004) compared to Group 1, while no difference was observed between Groups 2 and 3. Conclusion Tadalafil demonstrates potential efficacy in preserving testicular tissue and maintaining sperm parameters against damage induced by varicocele. These findings support further investigation into the role of phosphodiesterase type 5 (PDE5) inhibitors as adjunctive agents in male reproductive health.