EXAMINATION OF OXIDATIVE/ANTIOXIDATIVE STATUS AND TRACE ELEMENT LEVELS IN DOGS WITH MAMMARY TUMORS

B. Ozturk, T. S. F. Toydemir, S. S. Arun, I. Kirsan, O. Erdogan, A. Ates, S. O. Enginler, U. B. Barutcu, M. E. Or, S. Ozdemir

Abstract: The aim of this study was to detect differences in oxidative/antioxidative status in dogs with and without mammary tumors by monitoring the extent of lipid peroxidation (TBARS), activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST), and reduced glutathione (GSH) as well as trace elements required for antioxidative activities such as copper (Cu), zinc (Zn), selenium (Se), and manganese (Mn). Samples of mammary tumors were obtained from the experimental group by surgery, and healthy mammary glands, from the control group by surgical biopsy. Blood samples were collected before the surgery (day 1) and on 15th day post-surgery, while mammary tissue samples were collected after the surgery for the detection of antioxidant status, levels of trace elements, and histopathology. Antioxidant activities and levels of trace elements were compared between days 1 and 15 for serum samples, as well as between the control and experimental groups for tissue samples using repeated measures ANOVA and Student’s t test, respectively. Significantly higher activities of antioxidative enzymes SOD/CAT and GST were detected in serum samples (day 1) and tissue homogenates (tumor tissue), respectively, from dogs with mammary tumors compared to the control group; however, significantly higher SOD activity was observed in tissue homogenates from the control group, suggesting host defense against the tumor. The levels of trace elements also showed variations dependent on the occurrence of mammary tumors. In conclusion, higher plasma and tissue antioxidant activities in dogs with mammary tumors suggests the importance of considering antioxidants while
deliberating future treatment options for canine mammary tumors. Moreover, higher level of copper in tumor tissue suggests that it functions as a co-factor for antioxidant complexes.

Keywords: antioxidant; blood; canine mammary tumor; general anesthesia; mastectomy

Date published: 2017-09-20