Nirupama M. and Yajurvedi H. N
The study was to investigated whether stress induced testicular damage and its reversibility are duration of exposure dependent or not. Adult male rats were subjected to restraint for 1 hour and after a gap of 4 hours to forced swimming exercise for 15 minutes daily for 1, 4 and 6 months. There was a significant duration dependent decrease in testicular weight, number of germ cells in stage VII of spermatogenesis, concentrations of ascorbic acid and tocopherol; increase in counts of abnormal spermatozoa and degeneration of seminiferous tubules. In addition, in all the durations, a significant uniform decrease in the activities of testicular 3β-hydroxysteroid dehydrogenase and antioxidant enzymes, the serum testosterone levels and total sperm count and a significant increase in malondialdehyde levels were found. The rats exposed to stress for 1 month and allowed to recover for 4 months, showed restoration in the relative weight of testes, abnormal sperm counts, counts of A spermatogonia and spermatids and activities of superoxide dismutase, glutathione-s-transferase and the concentrations of malondialdehyde and tocopherol levels whereas other parameters showed significant increase over stressed rats, although they were lower than controls. All these parameters of rats exposed to stress for 4 or 6 months and allowed to recover for 4 months did not differ from respective stress groups. The results indicate that increase in duration of stress exposure leads to progressive deterioration in structure and functions of the testis and changes are irreversible following 4 months exposure in rats.