Comparison between Xylazine-Tiletamine-Zolazepam and Fentanyl-Tiletamine-Zolazepam Anaesthetic Combinations on Plasma Oxidative Status in Sheep

Abstract

It is important to determine varying effects of anaesthetics agents. One of the adverse effects of general anaesthetics are the exogenous sources of reactive oxygen species. In this study, the effects of xylazine-tiletamine-zolazepam (XTZ) and fentanyl-tiletamine-zolazepam (FTZ) combinations on plasma oxidant-antioxidant indicators were compared in sheep. Ten ewes received two different anaesthetic combinations in a ten-day interval. XTZ group was injected with xylazine and tiletamine-zolazepam. FTZ group was injected with fentanyl and tiletamine-zolazepam. Blood samples were collected before and at the 30, 60, 120 min, 24 h and 3 days after anaesthesia. Both anaesthetic regimens caused an increase in malondialdehyde (MDA) concentrations in plasma. The MDA concentrations at 60, 120 min and 24 h in the XTZ group were significantly higher than in the FTZ group. Glutathione (GSH) concentration at 30, 60, 120 min and 24 h was significantly lower than baseline values in XTZ group, while there was only a decrease at 120 min in the FTZ group. GSH concentrations in the XTZ group were significantly lower at 60 and 120 min compared with the FTZ group. Beta carotene concentration was decreased at 120 min and 24 h in the XTZ group, while it decreased only at 120 min in the FTZ group. Glutathione peroxidase (GSH-Px) and catalase (CAT) activities decreased at 120 min and 24 h only in the XTZ group. There were no significant differences in β-carotene concentration, activities CAT and GSH-Px activities between groups. In conclusion, both XTZ and FTZ anaesthetic regimens induced oxidative stress in sheep. XTZ combination has more detrimental effect than FTZ combinations on particularly MDA and GSH concentrations. Therefore, FTZ anaesthetic combination is considered to be more suitable for sheep anaesthesia, due to less deteriorating effects on oxidant/antioxidant balance.