Effects on the Lipid Peroxidation and the Antioxidant Defense Systems of the Use of Isoflurane or Sevoflurane in Calves Undergoing Surgery

Background: Incoming anaesthesia created by the use of many drugs with different physicochemical properties is a source of stress and trauma for the body. This event increases the oxidative response and changes the balance between oxidant/ antioxidant capacity in the organism in favor of oxidant capacity. This situation is defined as oxidative stress. For these reasons, studies are conducted to determine the effects of general anaesthetic agents on oxidant and antioxidant systems in the organism. In this study, it was aimed to determine the effects of isoflurane and sevoflurane used for general anaesthesia in humans and animals on lipid peroxidation and antioxidant defense system in calves. Materials, Methods & Results: The study included 14 calves of different breeds, ages, sexes, and weighing, average 2 weeks old. The cases randomly were divided into 2 groups, the isoflurane group (group I), and the sevoflurane group (group II), and each group included 7 animals. Before general anaesthesia, 0.04 mg/kg atropine was administered intramuscularly to all animals for premedication. At 15 min after atropine administration, isoflurane was administered at an inspiratory concentration of 3-5% in group I, and sevoflurane was administered at an inspiratory concentration of 5-7% in group II, via a face mask for 15 min for the induction of anaesthesia. Endotracheal intubation was performed in all cases at the 15 min of the induction period following the onset of general anaesthesia symptoms. After the induction, anaesthesia was continued at an inspiratory concentration of 1.5-3% in the isoflurane group and inspiratory concentration of 2.5-4% in the sevoflurane group. Blood samples were taken just before anaesthesia, just before skin incision, at the end of anaesthesia and surgery, and at the 24 h postoperatively. The malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and glutathione (GSH) levels were measured spectrophotometrically in samples. In group I, MDA and antioxidant parameters SOD, CAT, GSH-Px, GSH did not observe a significant change in their concentrations through the study (P > 0.05). In group II, MDA value decreased significantly before incision (P < 0.05), at the end of anaesthesia and surgery compared to the pre-anaesthesia level (P < 0.001), and then although increased significantly at 24 h postoperatively, the value was still lower than the pre-anaestesia level (P < 0.05). It was determined that SOD activity increased significantly after sevoflurane compared to pre-anaesthesia (P < 0.05) however, the increases in SOD activity detected during sevoflurane were not statistically significant (P > 0.05). During the study, a statistically insignificant increase was observed in the concentrations of CAT, GSH-Px, GSH compared to pre-anaesthesia (P > 0.05). Pre-anaesthesia values of all measured biochemical parameters did not differ significantly between groups (P > 0.05). Before skin incision, at the end of anaesthesia and surgery, and at the 24 h postoperatively MDA was lower (P < 0.05) and SOD activity was higher (P < 0.05) than in group I in group II. There was no statistically significant difference between the two groups in terms of CAT, GSH-Px, GSH levels between the other measurement times (P > 0.05). Discussion: An important advantage of sevoflurane compared to currently available anaesthetics is that it provides rapid induction due to its low solubility in blood and tissues, and rapid recovery due to its low solubility in fat. This feature is proof that the side effects of sevoflurane anaesthesia are minimal. The findings of this study show that sevoflurane exposure decreases lipid peroxidation and enhances antioxidant defense. The potential effect of sevoflurane on oxidative stress may lead to its preferred clinical use of sevoflurane compared to isoflurane.