Plasma glutathione peroxidase (gpx 3) activity in the freshwater turtle Trachemys scripta elegans after isoflurane inhalation anesthesia

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Olivera Valčić
Svetlana Milanović
Milan Došenović
Jòzsef Özvegy
Milena Radaković
Branislav Vejnović
Miloš Vučićević


Introduction. Gluthatione peroxidases are selenoenzymes which have a crucial role in the protection of animals against oxidative stress.

Materials and Methods. From September 2017 to April 2018 a group of eight red-eared sliders were admitted at the Clinic for Small Animals, Faculty of Veterinary Medicine University of Belgrade for elective diagnostic celioscopy.The turtles were of unknown age, weight from 1.20 kg to 1.86 kg. The anesthesia protocol involved using ketamine and medetomidine  both at a low dosage (10 mg kg-1 and 0.1 mg kg-1 , respectively) as induction after which anaesthesia was maintained using isoflurane  at 3% (vapour setting) in 100 % oxygen (0.5 L/min). Medetomidine was reversed with atipamezole 0.2 mg kg-1, given intramuscularly (IM). The elective celioscopy was done according to standard protocols. One day prior to anesthesia heparinized blood samples were taken using the subcarapacial venous plexus for venipuncture. The second sampling took place three hours after the anaesthetics were administered.

Results and Conclusions. GPx3 (n=8) activity in the blood plasma was measured by the coupled test as described by Günzler et al. (1974). Data were tested for normality by the Shapiro-Wilk normality test and the groups were compared using a paired t- test.

Blood plasma GPx 3 activity was significantly higher (p= 0.008545) after a three hour recovery period from inhalation anesthesia performed for elective diagnostic celioscopy. The measured post-anesthesia values were on average higher by almost 80% compared to the measurements prior to anesthesia. It can be concluded that the statistically significant increase in the activity of plasma GPx3 from 91.02±36.05 mKat/l prior to anesthesia to 160.21 ±58.94 mKat/l three hours after anesthesia is due to the change in oxygen concentration which is increased to 100% during the procedure thus exposing the turtles to conditions of high oxygen concentrations.


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Valčić, O., Milanović, S., Došenović, M., Özvegy, J., Radaković, M., Vejnović, B., & Vučićević, M. (2021). Plasma glutathione peroxidase (gpx 3) activity in the freshwater turtle Trachemys scripta elegans after isoflurane inhalation anesthesia. Veterinarski Glasnik, 75(1), 76-82.
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