INVESTIGATIVE UROLOGY

Effects of unilateral grade I testicular injury in rat
Srinivas M, Chandrasekharam VVSS, Degaonkar M, Gupta DK, Jha P, Jagannathan NR, Das SN
Department of Pediatric Surgery, Department of Nuclear Magnetic Resonance, Department of Reproductive Biology and Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, India
Urology 2002; 60:548-51

• 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. T1-weighted and T2-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.
  
  
• Editorial Comment
  Unilateral testicular lesions have the potential to affect also the contralateral testis function, probably due to immunologic damage following rupture of the blood-testis barrier. Nevertheless, the effect of unilateral blunt testicular trauma on subsequent testicular function is still poorly known. In the present work, the authors evaluated the effects of grade I testicular injury on germ cell status of the ipsilateral and contralateral testis, as well as the sex hormone status, in Wistar rats. All 10 rats in the experimental group had grade I trauma to the right testis that was confirmed by T1-weighted and T2-weighted magnetic resonance imaging (MRI). To our knowledge, this is the first study comparing the extent of damage in the traumatized and contralateral testis within the same experimental group, by using the sensitive techniques of MRI for confirming grade I trauma, and DNA flow cytometry for detecting germ cell alterations in the testis. The present results indicate significantly worse damage to the traumatized testis compared to the contralateral testis after unilateral blunt testicular trauma. Also, the study demonstrates that even grade I unilateral blunt testicular trauma significantly affects overall testicular function, by elevating FSH and estradiol levels, and lowering testosterone levels when compared to controls. In summary, the authors elegantly concluded that grade I unilateral blunt testicular trauma in prepubertal rats significantly affects germ cell maturation in both ipsilateral and contralateral testis and alters the sex hormonal profile.

Dr. Francisco J.B. Sampaio
Chairman, Urogenital Research Unit
State University of Rio de Janeiro
Rio de Janeiro, Brazil