Objective: 

The objective of this study was to examine the effect of melatonin administration on lipid peroxidation in the testis tissue of diabetic rats subjected to acute swimming exercise.

Methods: 

The study included 80 adult male Sprague-Dawley rats which were divided into 8 groups: Group 1, general control; Group 2, melatonin-administered control; Group 3, melatonin-administered diabetic control; Group 4, swimming control; Group 5, melatonin-administered swimming; Group 6, melatonin- administered diabetic swimming; Group 7, diabetic swimming; Group 8, diabetic control group. In order to induce diabetes, the experimental animals were injected with 40 mg/kg intraperitoneal (ip) streptozotocin (STZ) "Sigma, S-0130". The injections were repeated at the same dose after 24 hours. The animals whose blood glucose was found 300 mg/dlt and above 6 days after the last injection were accepted as diabetic. These animals were administered 3 mg/kg/day ip melatonin for 4 weeks. Levels of MDA and GSH were determined (by TBARS and ELLMANN methods, respectively) in the testis tissue of the rats decapitated at the end of the 4-week study.

Results: 

The highest MDA values in the testis tissue were found in groups 7 and 8 (p<0.001). Testis MDA values in groups 4 and 6 were lower than the levels in group 7 and 8, but higher than those in other groups (p<0.001). Group 5 had the highest testis GSH values (p<0.001). Group 6 had testis GSH values lower than group 5, but higher than all other groups (p<0.001). The lowest testis GSH levels were found in groups 7 and 8 (p<0.001).

Conclusions: 

Results obtained from the study indicate that melatonin administration can prevent the increase in free radical production and the inhibition of the antioxidant activity resulting from diabetes and acute exercise.