Histological and histochemical evaluation of changes in contralateral testicular angiotensin converting enzyme activity in unilateral testicular torsion

Testicular torsion is a pathological condition that causes ischemia on ipsilateral side and degenerative changes on the contralateral testis. Testicular angiotensin converting enzyme (tACE) is expressed in male germ cells, especially after termination of meiosis during spermiogenesis. tACE has been reported to have effects on spermiogenesis and fertility, sperm motility, capacitation and acrosome reaction. The aim of this study was to investigate the damage on contralateral testis after testicular torsion with light and electron microscopy and changes in tACE expression immunohistochemically.In this study, 36 adult, male Wistar rats were used. Rats were divided into six groups. Group I; Control, Group II; Sham group in which testes were fixed from their upper and lower poles, sutures were taken 12 hours later and testes were excised 24 hours after the latter procedure, Group III; Right testis was excised after 6 hours 720° counter clockwise torsion of left testis, Group IV; Left testis was detorsed after 6 hours of similar torsion and right testis was excised 24 hours later, Group V; Right testis was excised after 12 hours of similar 720° torsion of left testis, Group VI; Left testis was detorsed after 12 hours of similar torsion and right testis was excised 24 hours later.At the end of the experiment, right testes were taken for light and electron microscopic investigation, tACE immunereactivity was determined with Avidin- Biotin-Peroxydase method. Data were analysed with Mann-Whitney U test using proper computer program. p< 0.05 was accepted to be statistically significant.When evaluated under light microscopy, degenerative seminiferous tubules, germ cells with heterochromatic and pyknotic nucleus, seperation between germ cells and vacuolization in some tubules were observed on right testes. Electron microscopy revealed thinning of basement membrane, intracytoplasmic vacuolization in germinal cells and loss of intercellular junctions. When changes in tACE immunreactivity was assessed, it was 2.72 ± 0.14 in control group and 2.71 ± 0.15 in sham group, respectively. This ratio dropped to 2.16 ± 0.16 in Group III (p< 0.05). It was 2.38 ± 0.08 in Group IV, 2.64 ± 0.09 in Group V and 2.47 ± 0.17 in Group VI, respectively. In only 6 hours torsion group, this score was observed to be significantly decreased when compared to control group. Rest of the changes in the other groups were not statistically significant.In conclusion, unilateral testicular torsion causes contralateral histological changes. Decrease of tACE immunreactivity after 6 hours and its increase after prolongation of torsion period may reveal a compensatory mechanism to protect and maintain spermatogenesis. tACE is an enzyme that takes part in pathological processes like testicular torsion but further studies are required to enlighten the activities of this enzyme.