Effect of propofol on oxidative stress status in erythrocytes from dogs under general anaesthesia

BACKGROUND Alterations of the normal redox balance might be attributed to increase of plasma free-radical concentration and a disruption of the antioxidant defense system. One of the adverse effects of general anaesthetics is the exogen sources of reactive oxygen radicals that are responsible for several diseases. The purposes of the current study were to evaluate the effect of propofol on oxidative stress and to compare the differences between propofol induction only and induction plus continuous infusion on antioxidant status in dogs. FINDINGS Beagle dogs were evaluated in the present study. The dogs were assigned randomly to receive three treatments in a crossover model. The three treatments were: group 1 (n = 9), 2% isoflurane; group 2 (n = 9), anaesthesia induced with an intravenous (IV) bolus dose of 6 mg/kg propofol and maintained with 1.5-2% isoflurane; group 3 (n = 9), total IV anaesthesia (induction with 6 mg/kg propofol, infusion with 0.6 mg/kg/min propofol). The results of this study show that dogs exposed to isoflurane had decreased antioxidant enzymes activities, whereas dogs injected with propofol had increased antioxidant enzymes activities. CONCLUSIONS The results of this study showed that an infusion dose of propofol has antioxidant effects in dogs. These effects may be beneficial to patients in whom free radicals play a role in oxidative stress, such as those with ischemia. Further studies are needed to evaluate whether these antioxidant effects of the anaesthetic are of clinical value.