The effect of zinc aspartate pretreatment on ischemia-reperfusion injury and early changes of blood and tissue antioxidant enzyme activities after unilateral testicular torsion-detorsion

Background/purpose

The aim of this study is to investigate the effect of zinc aspartate (ZA) pretreatment on ischemia-reperfusion (I/R) injury and blood and tissue antioxidant enzyme activity early after unilateral testicular torsion-detorsion (T/D).

Methods

Forty prepubertal male Sprague-Dawley rats (weight 160 to 220 g) were divided into 4 groups each containing 10 rats. Surgery was conducted under intraperitoneal 1-shot ketamine (50 mg/kg) anesthesia. The scrotum was entered through a midline incision. Rotating the left testis 720° in a clockwise direction was the model of the testicular torsion. Group 1 was for the basal values. Group 2 had 4 hours T/D. Group 3 also had 4 hours T/D and pretreated with 50 mg/kg intraperitoneal ZA injection half an hour before detorsion. Group 4 was designed as a sham group. In the Group 2 and Group 3, the tunica vaginalis was opened, and left testicles were rotated clockwise 720° and maintained in this torsion position by fixing with a silk suture to the scrotal wall. The scrotum was closed and 4 hours later reentered for testicular detorsion. After spermatic cord detorsion, the scrotum was closed. At the end of 4 hours detorsion period, bilateral orchiectomies were performed, and 5-mL intracardiac blood samples were taken. Blood and tissue superoxide dismutase (SOD), catalase (CAT) activities, and malondialdehyde (MDA) levels were measured, and histopathologic examination was performed.

Results

Group 2 and group 3 had decreased blood SOD and CAT activities and elevated MDA levels indicating I/R injury. The 2 groups were also different from each other for these parameters reflecting the beneficial effect of ZA pretreatment (P < .05). The decreased ipsilateral tissue SOD and CAT activities in group 2 were different from the other groups including group 3 (P < .05). Ipsilateral tissue MDA levels of both group 2 and group 3 were elevated. Group 2 had higher values than group 3 (P < .05). In addition, specimens from group 2 had a significantly greater histologic injury than group 3 (P < .05). These findings were also supporting the beneficial effect of ZA pretreatment. All measurements of contralateral tests were similar to the basal values for all groups (P > .05).

Conclusions

ZA pretreatment reduces I/R injury by its antioxidant effects after unilateral testicular T/D and affects the antioxidant enzyme systems.