Atici, EmineMogulkoc, RasimBaltaci, Abdulkerim KasimMenevse, Esma2023-05-222023-05-2220181868-1883http://hdl.handle.net/11727/9095Background: A recently discovered hormone, irisin is accepted to be significantly involved in the regulation of body weight. Thyroid functions may be, directly or indirectly, associated with irisin. Aim: The aim of the present study is to determine the effect of experimental thyroid dysfunction on irisin levels in rats. Methods: The study registered 40 adult male Sprague-Dawley rats, which were allocated to groups as follows: 1. Control; 2. Hypothyroidism induced by injection of 10 mg/kg/day intraperitoneal propylthiouracil (PTU) for 3 weeks; 3. Hypothyroidism (PTU 2 weeks) + L-thyroxin (1.5 mg/kg/day for 1 week); 4. Hyperthyroidism induced in rats by 3-week thyroxin (0.3 mg/kg/day); 5. Hyperthyroidism + PTU. At the end of the study, blood samples were collected to quantify free triiodothyronine (FT3), free triiodothyronine (FT4) and irisin levels. Results: FT3 and FT4 levels were reduced in hypothyroidism and were significantly elevated in hyperthyroidism (p < 0.001). Irisin values, on the other hand, were found to be elevated in both hypothyroidism and hyperthyroidism groups (p < 0.001). Conclusion: The results of the study suggest that irisin values increase in thyroid dysfunction, hypo-and hyperthyroidism, and that when hypothyroidism is corrected by thyroxin administration and hyperthyroidism by PTU injection, plasma irisin values go back to normal.enginfo:eu-repo/semantics/closedAccesshyperthyroidismhypothyroidismirisinPTUthyroxinearticle3330004288126000052-s2.0-85037853523