Erythropoietin and sildenafil protect against ischemia/reperfusion injury following testicular torsion in adult rats

Abstract

Testicular torsion/detorsion causes severe tissue damage due to ischemia/reperfusion injury. The present study investigated the protective effect of erythropoietin and sildenafil against ischemia/reperfusion injury following unilateral testicular torsion/detorsion in adult rats. A total of 28 adult male rats were included, and were divided into the following groups: Group A (n=5), sham operated; groups B (n=5), C (n=5), D (n=5) and E (n=8), undergoing right testis torsion and detorsion after 90 min. Group B received no drug treatment. Rats in the groups C and D received low-dose (1,000 IU/kg) or high-dose (3,000 IU/kg) erythropoietin, while those in group E received sildenafil (0.7 mg/kg), through intraperitoneal injection after 60 min of torsion. The right testis was extracted 24 h after detorsion, and the tissue was subjected to histopathological examination and immunohistochemical assessment of cleaved caspase-3 expression. Histological alterations and the quality of spermatogenesis were scored according to the Cosentino and the Johnsen scoring systems, respectively. The results demonstrated normal testicular architecture in group A, while the other groups showed ischemic cellular damages, with the worst scores observed in group B. Groups D and E presented better scores compared with group C. Regarding the quality of spermatogenesis, the best scores were observed in group A, and the worst in group B. Groups C, D and E presented similar results, which were improved in comparison to group B, however, not compared to group A. Furthermore, cleaved caspase-3 levels were lower in groups A, D and E, with equal results observed. Group C had higher levels of cleaved caspase-3 compared with these groups, but lower than group B, which presented the highest cleaved caspase-3 levels. In conclusion, erythropoietin and sildenafil protect testis from ischemia/reperfusion injury by decreasing cellular damage and attenuating apoptosis.

Keywords: erythropoietin; ischemia/reperfusion injury; rats; sildenafil; testicular torsion; testis.

Figure 1.

Histological images of hematoxylin and eosin staining of rat testicular tissues in the (A) sham-operated, (B) torsion/detorsion without treatment, (C) torsion/detorsion + low-dose erythropoietin,(D) torsion/detorsion + high-dose erythropoietin, and (E) torsion/detorsion + sildenafil groups (original magnification, ×100).

Figure 2.

Histological images of immunohistochemical stain for cleaved caspase-3 in the (A) sham-operated, (B) torsion/detorsion without treatment, (C) torsion/detorsion + low-dose erythropoietin,(D) torsion/detorsion + high-dose erythropoietin, and (E) torsion/detorsion + sildenafil groups (original magnification, ×400).