Effects of unilateral grade I testicular injury in rat.

Objectives: The effect of unilateral blunt testicular trauma on subsequent testicular function is still debated. None of the experimental studies had the exact grading of testicular injury and evaluation of hormone status and hence this study was designed.

Methods: Twenty male prepubertal (20 days old) Wistar rats were divided into two groups: group 1 (n = 10) underwent sham surgery; group 2 (n = 10) underwent blunt trauma to the right testis by a 5-g sterile weight dropped three times on the testis from a height of 10 cm. T(1)-weighted and T(2)-weighted magnetic resonance images were taken within 6 hours to confirm grade I injury. At 60 days of age, blood samples were obtained from each rat for follicle-stimulating hormone, luteinizing hormone, testosterone, and estradiol levels, and both testes of each rat were harvested separately for DNA flow cytometric analysis.

Results: Group 2 rats had significantly reduced (P <0.001) haploid cell populations in both right and left testis compared with the corresponding testis of the group 1 rats. Within group 2, the right testis was significantly (P <0.001) more affected. Serum levels of testosterone were significantly lower (P <0.05) and follicle-stimulating hormone (P <0.01) and estradiol (P <0.05) levels were significantly higher in group 2 rats than in group 1 rats. However, the luteinizing hormone levels were not significantly different.

Conclusions: Grade I unilateral blunt testicular trauma in prepubertal rats significantly affected germ cell maturation in both ipsilateral and contralateral testis and altered the sex hormone profile.