Aim: The endocrine function of the testis was carried out by Leydig cells which produce testesterone. In experimental studies, it was demonstrated that N₂O had negative effects on spermatogenesis especially in increasing concentrations with respect to time. In this study, we assessed the effects of N₂O administration on rats at different exposure times on testesterone levels.

Materials and Methods: A total of 55 Wister-Albino rats were kept in specially prepared cown and divided into two groups as study and control. The study consisted of 4 groups: The mixture of 20% O₂ and 80% dry air-gas mixture was applied for 30 days to control group (n=10), group I received 10% N₂O + 20% O₂ and 70% dry air-gas mixture for 10 days (8 hours/day)(n=15), same protocol was applied to group II for 20 days (n=15) and for 30 days to group III (n=15).

Results: There was no statistically significant difference between study groups (groups I, II and III) and the control group in respect to body weights, testicular weights and testesterone levels.

Conclusion: In our study, there was no change in the levels of testesterone.