Effects of Flavobacterium psychrophilum extracellular products and lipopolysaccharide antigens on the antioxidant enzyme system activity of rainbow trout (Oncorhynchus mykiss) fry

The aim of this study was to investigate the response different doses lipopolysaccharide (LPS) and extracellular product (ECP) antigens (25, 50, 100, 250, 500 µg) obtained from Flavobacterium psychrophilum changes in oxidative stress parameters (catalase [CAT], superoxide dismutase [SOD], glutathione peroxidase [GPx], glucose 6-phosphate dehydrogenase [G6PD], reductase [GR], malondialdehyde [MDA]) juvenile rainbow trout. For purpose, 6 F. (102–106) were applied fish, lethal dose 50 % (LD50) value determined as 1.33·104. Changes MDA levels antioxidant enzymes by applying 25 LD50 fish for 14 days. Accordingly, while increased GR, G6PD, GPx, SOD activity, it decreased CAT activity. Initially, 25, µg ECP LPS fish; after 21 days, a these fish. Fourteen days later, taken, examined. As result, that application there an increase