Oxidative Stress Biomarkers in Liver of Sea Trout (Salmo trutta m. trutta L.) affected by Ulcerative Dermal Necrosis Syndrome

摘要

Antioxidant defense system and oxidative stress biomarkers were determined in the liver tissue from males and females of sea trout (Salmo trutta m. trutta L.) affected by Aeromonas hydrofila infection causing ulcerative dermal necrosis (UDN) syndrome. Histological results from hepatic parenchyma in UDN-affected trout show that cytoplasmic vacuolation of hepatocytes, loss of normal basophilia by cytoplasm, presence of pigment deposition in the parenchyma are a signs of liver deterioration. Impaired circulation in the liver of UDN-affected females manifests in oedema and an occurrence of a large number of erythrocytes in the sinusoids and the intercellular space. In both UDN-affected males and females, protein oxidation showed higher values as compared to the healthy trout. UDN syndrome caused a decrease of antioxidant enzyme activities. This might be due to inactivation of the above-mentioned enzymes by the end products of protein oxidation. The importance of the glutathione-mediated antioxidant defense system in UDN-induced oxidative stress was demonstrated. Results showed that UDN syndrome led to an oxidative stress in liver tissue able to increase of the oxidatively modified protein level.