Mogulkoc, RBaltaci, AKOztekin, EAydin, LTuncer, I2020-03-262020-03-2620050172-780Xhttps://hdl.handle.net/20.500.12395/19762OBJECTIVE: The present study aimed at determining how 3-weeks intraperitoneal melatonin administration affected oxidative stress caused by experimental hyperthyroidism. MATERIALS AND METHODS: The study was conducted on 30 male rats of Spraque-Dawley species. The experimental animals were divided to 3 groups (control, hyperthyroidism and hyperthyroidism+melatonin). The supplementation was continued for 3 weeks after which the animals were sacrified and tissue malondyaldehyde (MDA) and glutathione (GSH) levels were determined. RESULTS: MDA levels in kidney and testis tissues in hyperthyroidism group were higher than those in control and hyperthyroidism+melatonin administered groups (p < 0.001) and levels in hyperthyroidism + melatonin administered group were higher than those in the control group (p < 0.001). The highest GSH levels were obtained in hyperthyroidism + melatonin-administered group (p < 0.001) and GSH levels in hyperthyroidism group were higher than those in the control group (p < 0.001). CONCLUSION: Results of the study demonstrate that hyperthyroidism induced by 3-weeks L-thyroxine administration increased oxidative stress in kidney and testis tissues and that although melatonin administration inhibited this stress to a certain extent, it could not bring the stress down to the level in controls.eninfo:eu-repo/semantics/openAccesshyperthyroidismmelatonin administrationoxidant stresskidneytestisArticle26680681016380687Q4WOS:000236048900036Q4