The effects of excessive starvation on antioxidant defence and lipid peroxidation in intensively reared, commercial-size pikeperch (Sander lucioperca L.)

Abstract

The present study investigated the influence of various lengths of starving periods on lipid peroxidation and on parameters of the glutathione redox system – as reduced glutathione (GSH) concentration and glutathione peroxidase (GPx) activity – in meat and liver of commercial-size pikeperch. Forty cultured, market size (average body weight: 732.2 ± 129.8 g), mixed sex pikeperch were divided into 5 groups (n = 8 in each), where the experimental groups were withdrawn from feed for 3 and 6 weeks. After respective periods, fish were slaughtered immediately. Increasing the length of the starving period reduced the body weight, mainly due to losses in intraperitoneal and intramuscular fat. Due to starvation, higher rate of lipid peroxidation was found, as measured by the significantly higher malondialdehyde (MDA) concentration in the liver (36.59 ± 11.11 vs. 17.90 ± 3.13 μmol/g wet weight) and meat (35.25 ± 6.28 vs. 26.99 ± 9.60 μmol/g wet weight), which was probably caused by the impairment of the glutathione redox system. Lower GSH concentration (1.42 ± 0.32 vs. 2.81 ± 0.32 µmol/g protein) and GPx activity (1.53 ± 0.38 vs. 2.59 ± 0.35 U/g protein) were also found in liver. The results indicate that long-term starvation impaired the amount and/or activity of glutathione redox system, and consequently increased the rate of lipid peroxidation in pikeperch. Keywords: Antioxidant defence, Lipid peroxidation, Pikeperch, Starvation, Glutathione, Malondialdehyd