Antioxidant enzyme activity in dogs with acute uraemia managed with haemodialysis

Impairment in antioxidant enzyme activity is involved in several compli- cations in human patients managed with intermittent haemodialysis (HD). Different factors, concerning uraemia and HD treatment, can promote oxidative stress in these patients. HD may generate oxidative stress due to several factors, such as reduced dialyzer biocompatibility, extensive contact between blood and synthetic surfaces of extra- corporeal circuit, and poor dialysate sterility. The aim of the present study was to evaluate antioxidant enzyme activity between pre- and post- haemodialysis treatment in dogs with acute uraemia, and its cor- relation with systemic inflammatory response syndrome (SIRS), and dis- seminated intravascular coagulation (DIC). Ten uremic dogs managed with HD (HDG) and ten clinically healthy dogs (CG) were included. Enzymatic activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) were assessed in blood hemolysates of dogs of both groups. In HDG dogs, blood samples were taken imme- diately before HD, and at the end of HD (15 seconds into bypass at standard blood flow of 50 mL/min). HDG dogs were classified accord- ing to IRIS guidelines for AKI. The presence of SIRS and DIC were diag- nosed on the basis of emathological, biochemical and coagulation profile according to the recently published criteria. Enzymatic activities of CAT, SOD and GPx were compared among CG, pre HD treatment (n = 17) and post HD treatment (n = 17), using the Tukey's Multiple Comparison Test. Enzymatic activities of CAT, SOD and GPx showed no significant differences between pre-dialysis and post-dialysis values, although GPx was significantly increased (P < 0.0001) in HDG com- pared to CG. Dogs with DIC (n = 4) showed significantly lower CAT (P < 0.0001) and GPx (P < 0.0001) levels, than dogs without DIC (n = 6). CAT and GPx activities in patients with SIRS (n = 3) appeared to be significantly lower than patients without SIRS (n = 7). In our cohort of dogs, intermittent HD did not seem to significantly affect antioxi- dant enzyme activity. However the reduced enzymatic activities in ure- mic dogs with DIC and SIRS is worthy of further investigations.