Objective: To observe long-term effects of contralateral testis with unilateral testicular torsion/detorsion in prepubertal rats

and investigate the protective effect of Shengmai injection on it. Method: Twenty-four healthy male SD rats aged 5 weeks were equally randomized into a Shengmai injection group (experimental group)

saline group(control group)and a sham operation group

8 rats per group. The rats with testicular torsion were killed after 7 weeks of surgery and excised their right testes and epididymides immediately for the measurement of superoxide dismutase (SOD)

nitric oxide synthase (NOS) activity and malondialdehyde (MDA) content in the testis

the weights of testis and the sperm motility in epididym. Result: Compared with the controls

the experimental group and the sham operation group exhibited a remarkable increase in the weights

the sperm motility

SOD activity (P<0.05) and an obvious decrease in NOS activity

MDA content(P<0.05). Compared with the sham operation group

the experimental group showed no significant changes in the sperm motility

the weights of testis

SOD

NOS activity and MDA content. Conclusion: The contralateral testis of prepubertal rats can be damage dafter unilateral testicular torsion/detorsion. Shengmai injection has the long-term protective effect role in prepubertal rat testicular injury after torsion/detorsion.