L. P. Smirnov

Biochemical response of blue mussels Mytilus edulis L. from the white sea to rapid changes in ambient temperature

The effect of rapid changes in ambient temperature on the biochemical profile of the blue mussel, Mytilus edulis L., was studied under aquarian conditions. It was shown that modifications in the content of reserve and structural lipids and their fatty acids, activity of lysosomal enzymes (β-glycosidase, cathepsins B and D), cytosolic calcium-dependent proteases (calpains) and phase II enzymes of xenobiotic transformation (glutathione S-transferase) reflect a nonspecific compensatory response of bivalves to the stress-inducing effect of environmental factors and indicate a metabolic rearrangement which occurs in mussels within the first hours of temperature changes. High initial level of glutathione S-transferase activity in control mussels as well as elevation of glutathione concentration during experiment may promote favorable recovery of mussels from the hypometabolic state.

Lipids of Microorganisms of the Family Vibrionaceae, Causative Agents of Fish Diseases

Lipid fractions and fatty acid compositions of microorganisms from the genera Aeromonas, Pseudomonas, and Vibrio(the family Vibrionaceae) that cause diseases of various fish species were studied. Motile aeromonads and vibrios displayed higher relative contents of membrane lipids and oleic acid and lower relative contents of storage lipids compared with nonmotile aeromonads and pseudomonads, which is connected with the activities of their movements. Nonmotile aeromonads and vibrios exhibited higher levels of polyunsaturated fatty acids and higher absolute phospholipid contents compared to motile aeromonads and pseudomonads. This is likely to be related to the host specificity of these bacteria and reflects the specific patterns of fatty acid compositions of the infected fish (salmonid and cyprinid) tissues.

Cytoplasmic protein vaccine against bacterial hemorrhagic septicemia (Aeromonosis) of fish

Water-soluble proteins fromAeromonas sobria, a causative agent of bacterial hemorrhagic septicemia of fish, were separated into six fractions by gel chromatography on Sephadex G-100. Injections of fraction II (67 kDa) provided the highest protection of carp against the disease. Injections of proteins contained in fraction II caused stronger effects on certain biochemical parameters in the fish liver (fatty acids of phospholipids and cathepsin B and D activities) in comparison to infections of the live culture.

Seasonal variability of some biochemical parameters in the whitefish (Coregonus muksun and Coregonus lavaretus)

The base levels and seasonal variability of ethoxyresorufin-O-deethylase (EROD) activity, glutathione-S-transferase (GST) activity, reduced glutathione concentration (GSH) and phospholipids concentration (PhL) of Coregonus lavaretus (Linnaeus, 1758) and Coregonus muksun (Pallas, 1814) were investigated. The relationships between this biochemical markers, hepatosomatic index and seasonal growth were also examined.

Role of glutathione in functioning of the system of antioxidant protection in fish (review)

Oxidative stress causes damage to cell components by reactive oxygen species (ROS) originating from the effect of various chemical pollutants, such as heavy metal cations, polyaromatic hydrocarbons, organochlorine and phosphororganic pesticides, polychlorine biphenyls, dioxins, and other xenobiotics. To avoid pathological consequences of interaction between biological molecules and high-reactive ROS, cells have a detoxification mechanism that uses glutathione, a nonprotein thiol. Glutathione is a component of cellular protection against the toxic action of xenobiotics and metal cations. In the last decade, the effect of environmental pollutants on changes in glutathione concentrations in tissues of aquatic organisms has been touched on in a large number of works. This review summarizes data of the up-to-date studies on glutathione variability in fish tissues under the effect of biogenic and industrial xenobiotics.

Some biochemical parameters of the transformation of xenobiotics in the freshwater pearl mussel Margaritifera margaritifera

We determined the concentration of glutathione (GSH) and the activity of glutathione S-transferase (GST) in the gills and hepatopancreas of the freshwater pearl mussel Margaritifera margaritifera L. It was found that the concentration of GSH in the gills decreases with a decrease in temperature, which indicates that metabolic processes in these ectothermic animals are decelerated. It was also found that changes in the concentration of GSH and in the activity of GST do not depend on age; thus, these biochemical markers can be used as bioindicators regardless of age. No substrate-specific activity of GST was observed, which means that freshwater pearl mussels have limited ability to metabolize compounds with different chemical structures.

Biochemical Characterization of Aeromonad Strains Differing in Pathogenicity

A virulent strain of motile aeromonad (77-18) differed from an avirulent strain (78-16) in the contents of lipids and phospholipids and odd-numbered fatty acids, activity of hydrolytic enzymes, and amount of proteins with molecular weights of 47–56 kDa. It is assumed that proteins with molecular weights of 47–56 kDa, proteolytic enzymes active within a wide pH range, and odd fatty acids may act as pathogenicity factors. Each of these compounds or their combination determines a certain stage of infection.