Durak, İ.Çimen, M.Y.B.Kaçmaz, M.Büyükkoçak, S.Öztürk, H.S.2025-05-102025-05-1020001528-739410.1080/0098410001567092-s2.0-0034646934https://doi.org/10.1080/009841000156709https://hdl.handle.net/20.500.14720/6321Antioxidant defense capacity was investigated in myocardial tissue from guinea pigs treated with 5-fluorouracil (5-FU) at a dose of 400 mg/kg/d daily for 5 d administered intraperitonally. Treatment with 5-FU lowered the activities of cardiac superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) accompanied by higher catalase (CAT) activity. Further, antioxidant potential (AOP) values were lower but oxidation resistance (OR) and malondialdehyde (MDA) levels were higher in the 5-FU-treated tissue. With regard to myocardial iron (Fe) and copper (Cu) levels, no significant differences were found between the groups. Results suggest that 5-FU treatment causes impairment in the myocardial antioxidant defense system and leads to cardiac peroxidation. It has been postulated that these changes might be responsible for the 5-FU cardiotoxicity seen in some patients, and antioxidant therapy might provide a therapeutic advantage. © 2000 Taylor & Francis Group, LLC.eninfo:eu-repo/semantics/closedAccessArticle597N/AQ25855891077724910777249WOS:000086199800005