Acetylcholinesterase activity and total antioxidant levels in dogs with mammary tumors before and after surgical removal

Objective. The aim of this study was to evaluate AChE activity in total blood and the FRAP levels in samples from dogs with mammary tumors before and after surgery, as well as the relationship between these variables with immunohistochemical markers of tumor (E-caderina, ki-67, COX-2). Materials and methods. In this study, 13 dogs with mammary tumors were divided into two groups (A and B). The group A was formed by dogs with tumors smaller than 3 cm of diameter, and the group B was formed by dogs with tumor of 3 cm of diameter or larger. The AChE activity and FRAP levels were evaluated before and after surgery and the immunohistochemistry were performed at the tumors. Results. The AChE activity was significantly increased (p<0.05) in dogs with mammary cancer compared to control animals, and neither surgery or tumor size affected the AChE activity (p>0.05). FRAP levels before surgery were significantly lower (p<0.05) compared to control animals. Also, FRAP levels increased significantly after surgery in animals of the group A compared to data before surgery, a fact not observed in dogs from the group B. E-cadherin showed low significant positive correlation with FRAP levels (r=0.37, p-value=0.05); COX-2 showed a moderate significant positive correlation to FRAP (r=0.55, p-value<0.05); and COX-2 showed a low significant positive correlation to AChE (r=0.32, p-value=0.01). Conclusions. AChE and antioxidant levels are modified in dogs with mammary cancer. These variables are involved in various physiological functions, and thus, they might be related to disease pathogenesis.