Fatty Acid Composition of Total Lipids in Atlantic Salmon Salmo salar L. Parr and Smolts Reared in Aquaculture at Various Lighting Regimes.

Continuous artificial lighting (24LD) was introduced experimentally in the standard technology to grow salmon juveniles in a southern region (Republic of North Ossetia-Alania) and its effect on fatty acid (FA) composition of total lipids in muscles and the liver was assessed in parr and smolts of the Atlantic salmon Salmo salar L. Changes in the key FA were observed in the FA spectrum of fish, indicating that smoltification was complete and that smolts were ready for new habitat conditions. Thus the content of polyunsaturated FAs (PUFAs) significantly increased as a result of an increase in (n-3) PUFAs, and, in particular, marine-type 22:6(n-3), and high values were observed for (n-3)/(n-6) and 22:6(n-3)/18:3(n-3) PUFA ratios. The most significant changes were detected in muscles. In all experimental groups, a decrease in saturated FAs (SFAs) and an increase in total lipid unsaturation was attributed primarily to PUFAs, while monounsaturated FAs (MUFAs) decreased along with SFAs. The experimental data on the lipid and FA composition in salmon juveniles and a higher proportion of smolts in the test groups indicated that smoltification was the most successful in groups with continuous lighting and 24-h feeding and a natural regime of lighting and feeding.

Phospholipid Composition of Fingerlings of Atlantic Salmon Salmo salar during Growth and Development in Aquaculture: The Effect of Different Lighting and Feeding Regimes.

The effect of different feeding and lighting regimes (natural and continuous) on the phospholipid composition of Atlantic salmon fingerlings reared in commercial aquaculture in the summer-autumn period in North Ossetia-Alania was studied. Qualitative and quantitative determination of phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol, lysophosphatidylcholine, sphingomyelin was performed by high-performance liquid chromatography. A decrease (September-November) in the content of the studied phospholipids in fingerlings decreased, which should be considered primarily as a biochemical adaptation of development and preparation of juveniles for the upcoming smoltification. The effects of lighting and feeding regime on phospholipid composition were found mainly in the fish reared under constant lighting and 24/7 feeding and the fish reared under natural light and feeding during daylight hours. However, the observed changes were not specific to a particular experimental group of fish in the framework of this study.

Activities of Energy Metabolism Enzymes in Atlantic Salmon Salmo salar L. Smolts and Parr Grown under Different Light Regimens.

Activities of enzymes of energy and carbohydrate metabolism in muscles and the liver were studied in Atlantic salmon Salmo salar L. smolts and parr grown under continuous or natural lighting and different feeding regimens in autumn followed by a short photoperiod in winter. Enzyme activities were found to differ between test and control salmon groups and between parr and smolts sampled at the end of the winter period. Smolts grown under continuous lighting and round-the-clock feeding differed from other groups by having higher cytochrome c oxidase (COX) activity and lower aldolase activity in muscles. Differences in aerobic metabolism in muscles between parr and smolts were found to be the same in all experimental groups, COX and aldolase activities being relatively higher in smolts. The pattern of changes in enzyme activities in the liver from parr to smolts differed between different experimental groups. Based on the results, the photoperiod was assumed to affect the activities of energy metabolism enzymes in salmon juveniles and may eventually affect the completion of smoltification.

Comparative Study of Lipid Content in Leptoclinus maculatus Postlarvae from Kongsfjord and Rjipfjord, Svalbard Archipelago.

A comparative study of lipid profile of the daubed shanny Leptoclinus maculatus postlarvae from fjords of different domains (arctic-boreal Kongsfjord and high-arctic Rjipfjord) of Svalbard Archipelago waters in summer was performed. A more efficient accumulation of lipids in the fishes from Kongsfjord compared to Rjipfjord due to triacylglycerols and wax esters was established. These differences may be related mainly to the trophic conditions of the habitat (species composition, abundance, and availability of food items). The higher level of cholesterol esters than wax esters at the L1 stage of development of the daubed shanny postlarvae compared to older fishes pointed to their active feeding mainly on phytoplankton. The differences in the content of certain classes of phospholipids may indicate adaptive changes at the level of biomembranes, contributing to the maintenance of cell homeostasis in response to abiotic environmental factors, and reflect their additional intake with food at the early stages of fish development.

Na+/K+-ATPase Activity in Smolts of Pink Salmon Oncorhynchus gorbuscha (Walbaum, 1792) from the White Sea Exposed to Fresh, Estuarine, and Sea Water.

The Na+/K+-ATPase (NKA) activity in smolts of pink salmon Oncorhynchus gorbuscha (a salmon species introduced in 1959 into the rivers of the Kola Peninsula) was studied in a ten-day cage experiment with fresh, estuarine, and sea water; the fish were caught during seaward migration in the Indera River of the White Sea basin. The development of tolerance to increased salinity in pink salmon smolts was accompanied by NKA activation. In estuarine water characterized by salinity fluctuations (from fresh to sea water) and in the marine environment (28‰), the NKA activity in pink salmon smolts was significantly higher than in the individuals kept in the cages installed in fresh water. The hypoosmoregulatory ability of pink salmon fry was registered, these data indicated that smoltification in this fish species took place in early ontogenesis. The changes in NKA activity evidenced the readiness of migrating pink salmon fry for the marine phase of their life cycle.

Fatty Acids Distribution in Seston, Tissues, and Faecal Pellets of Blue Mussels Mytilus edulis L.

The n-3 polyenoic fatty acids (phytoplankton origin) dominate in the fatty acid composition of seston, which is a food source for bivalves; this indicates the predominance of diatoms in the seston composition. The distribution of the main classes of lipids and their fatty acids in the tissues of blue mussels depends on the mollusk body size. As the body size of the mollusk increases, the ratio of membrane lipids decreases, and high-energy saturated and monounsaturated fatty acids accumulate in storage lipids. The bulk of the n-3 polyenoic acids consumed by mollusks in seston (i.e., their food) accumulates in the tissues of mollusks and is used for their metabolism, whereas the long-chain saturated fatty acids, oleic acid and the n-6 polyenoic acids, are excreted with faecal pellets.

Activity of Metabolic Enzymes in Farmed Rainbow Trout Oncorhynchus mykiss Walb. Affected by Bacterial Septicemia: The Effect of Food Additives.

The effect of food additive including antioxidant dihydroquercetin and polysaccharide arabinogalactan on the activity of metabolic enzymes in muscles and liver of artificially grown rainbow trout Oncorhynchus mykiss affected by bacterial infection was investigated. The results of the study indicated an increase in the resistance of trout to the action of bacterial infection with the enrichment of the diet with the studied bioactive components, apparently mediated, among other factors, by the activation of metabolic pathways of synthesis of energy and reducing equivalents.

Activity of the Enzymes of the Energy and Carbohydrate Metabolism in the Organs of the Three-Spined Stickleback Gasterosteus aculeatus from Different Biotopes of the White Sea.

The activity of the key enzymes of the energy and carbohydrate metabolism (cytochrome c oxidase, lactate dehydrogenase, aldolase, and glucose-6-phosphate dehydrogenase) have been studied in the three-spined stickleback Gasterosteus aculeatus spawning in different biotopes of the White Sea (Sel'dyanaya Bay, Sukhaya Salma Strait, and Kolyushkovaya Lagoon). It was found that individuals of stickleback from different spawning grounds differed mainly in the level of anaerobic metabolism and in the degree of utilization of carbohydrates during glycolysis. The results testify to the existence of adaptive mechanisms for the restructuring of the metabolic pathways of the energy metabolism depending on habitat conditions in different biotopes during the spawning period.

Dynamics of Estradiol Level during Metamorphosis in the Daubed Shanny (Leptoclinus maculatus, Fries, 1838) from Spitsbergen Island.

The estradiol content of muscles during metamorphosis in the daubed shanny (Leptoclinus maculatus) from different fjords of Spitsbergen Island, Svalbard, have been studied using mass spectrometry. The level of estradiol at the L4 larval stage of development is significantly lower than at the L2 stage. Values of this parameter in adults are significantly higher than in post-larvae (stage L5). Variations in the estradiol level during metamorphosis can be associated with the growth stimulation and regulation of the process.

Characteristics of the energy metabolism of the White Sea herring Clupea pallasii marisalbi Berg (Clupeiformes, Clupeidae) of Onega Bay, Dvina Bay, and Kandalaksha Bay of the White Sea.

The activity of the enzymes of the energy and carbohydrate metabolisms (cytochrome-c oxidase, L-lactate dehydrogenase, aldolase, and glycerol-1-phosphate dehydrogenase) have been studied in White Sea herring (the 1+, 2+, and 3+ age groups) sampled in Onega Bay, Dvina Bay, and Kandalaksha Bay of the White Sea. The bays differ in the hydrological regime, ecological and feeding conditions. The individual variability of the enzyme activity was the largest in the herring of the age 1+. The flexibility of the intensity and vector of the basic metabolic reactions probably supports the energy homeostasis, preconditions the switching to the most effective way of using the resources, and regulates the synthesis of the structural and storage molecules, as well as vectors the adaptation strategy of herring specimens of each age group to the hydrological regime, environment, and feeding conditions of the particular bay, corresponding to their age-related characteristics.

The level of cytokines and expression of caspase genes in rheumatoid arthritis.

The level of TNFα and IL6 in the blood plasma of patients with rheumatoid arthritis (RA) who received antiinflammatory therapy with methotrexate (MT) was significantly lower than in the patients without MT treatment. The level of caspase 6 and 9 gene transcripts in peripheral blood lymphocytes in patients with rheumatoid arthritic diagnosed for the first time and in patients with MT treatment were not significantly different. At the same time, the level of caspase 3 mRNA expression was significantly higher in the cells of the RA patients with MT therapy compared to the patients without MT therapy.

[Degradation of skeletal muscle protein during growth and development of salmonid fish].

Published data and the results of the authors' own studies on the role of intracellular proteolytic enzymes and the metabolic and signaling processes regulated by these enzymes at certain stages of growth and development of salmonid fishes are analyzed in the present review. The major pathways of intracellular proteolysis relying on autophagy, proteasome activity, and calpain activity are considered, as well as the relative contribution of these pathways to proteolysis in skeletal muscle of the fish. Skeletal muscle accounts for more than half of the weight of the fish and undergoes the most significant changes due to the action of anabolic and catabolic signals. Special attention is paid to the intensity of protein degradation during the active growth period characterized by a high rate of protein synthesis and metabolism in fish, as well as to protein degradation during the reproductive period characterized by predomination of catabolic processes in contrast to the growth period. Skeletal muscle plays a unique role as a source of plastic and energy substrates in fish, and, therefore, the process of muscle protein degradation is regarded as a key mechanism for the regulation of growth intensity in juvenile salmon and for maintenance of viability and reproductive capacity of salmonid fish during the maturation of gametes, starvation, and migration related to spawning. The possibility of using a set of parameters of intracellular proteolysis to characterize the early development of salmonids is demonstrated in the review.

[Circadian CLOCK Gene Variants, Parameters of Arterial Stiffness and Blood Pressure Levels in Subjects Without Arterial Hypertension].

CLOCK gene polymorphic variants, parameters of arterial stiffness and blood pressure (BP) variability were studied in 115 normotensive Russian patients without cardiovascular diseases (62 men, 53 women; mean age 36.4+/-1.01 years). Examination included ECG, 24h BP monitoring, duplex scan of carotid arteries, registration of vascular stiffness parameters, and genotyping of the following polymorphic markers of CLOCK: 3111T>C (3-untranslated region), 862T>C (exon 9) and 257T>G (promoter region) by PCR-RFLP method. Pulse wave velocity was not significantly different among carriers of various 257T>G, 862T>C, 3111T>C genotypes. Augmentation index (Aix night, Aix max) values were lower in individuals with genotypes allegedly associated with essential hypertension and ischemic heart disease (257GG, 862CC, 3111CC). Arterial stiffness index (ASI) was significantly higher in men having CC genotype of 862T>C. Polymorphic variants 257T>G and 862T>C SNPs of CLOCK gene were found to be associated with parameters reflecting BP variability (morning rise of diastolic BP and rate of BP rise). These results provide a basis for suggestion that the CLOCK gene polymorphism is one of factors determining elastic properties of vascular wall. The suggestion is supported by discussion of possible molecular mechanisms of circadian genes impact on elasticity and rigidity of vessel.

[Activity of Enzymes Involved in the Energy and Carbohydrate Metabolism and the Level of Some Molecular-Genetic Characteristics in Young Salmons (Salmo salar L.) with Different Age and Weight].

In order to investigate the metabolic regulation in Atlantic salmon fries (Salmo salar L.) during their growth, development, and in the course of size divergence, age-related changes in the activity of enzymes involved in the energy and carbohydrate metabolism, including myosin heavy chain isoform expression, RNA/DNA ratio in the white muscles and liver of specimens at ages of 0+; 1+, and 2+, as well as correlations of these characteristics with the body weight of fish specimens were analyzed. Multidirectional changes in the activity of enzymes taking part in aerobic and anaerobic energy metabolism, as well as a decrease in the protein synthesis with age, were revealed. There was a positive correlation between the activities of cytochrome oxidase, lactate dehydrogenase, aldolase, and myosin gene expression in the muscles, cytochrome oxidase activity, glucose-6-phosphate dehydrogenase, and glycerol-3-phosphate dehydrogenase in the liver with the body weight of salmon specimens within the age groups.

The role of lysosomal proteinases and estradiol in neurodegeneration induced by beta-amyloid.

Activation of lysosomal degradation process in nervous tissue may be neuroprotective. One of the factors that may influence on expression of lysosomal proteinases is the sex hormone, estradiol (E2). In this regard the expression of lysosomal proteinases after intracerebral injection of beta-amyloid peptide (Aß) was investigated as well as the neuroprotective effect of E2 in Aß-induced neurodegeneration. Intracerebral injection of Aß was shown to cause the significant increase in expression of cathepsin D in rat hippocampus and cerebral cortex. On the background of Aß intoxication, E2 treatment resulted in further increase in cathepsin D gene expression in hippocampus region and in its lowering to the control level in cerebral cortex. It was demonstrated for the first time that neuroprotective effect of E2 may be mediated by cathepsin D up-regulation.

[Intracellular Protein Degradation in Growth of Atlantic Salmon, Salmo salar L].

A brief review on the common characteristics and specific features of proteolytic machinery in fish skeletal muscles (based on Atlantic salmon, Salmo salar L., Salmonidae) has been given. Among a variety of proteases in the muscle tissue, those determining protein degradation level in developing and intensively growing muscles in salmon young and by this way regulating protein retention intensity and growth at all namely lysosomal cathepsins B and D and calcium-dependent proteases (calpains) were comprehensively studied. Revealed age-related differences in intracellular protease activity in salmon skeletal muscles indicate the role of proteolysis regulation in growth in general and a specific role of the individual proteolytic enzymes in particular. The data on negative correlation of cathepsin D and calpain activity levels in muscles and the rate of weight increase in juvenile salmon were obtained. A revealed positive correlation of cathepsin B activity and morphometric parameters in fish young presumably indicates its primary contribution to non-myofibrillar protein turnover.

[Modulation of Ca(2+)-Dependent Proteiolysis under the Action of Weak Low-Frequency Magnetic Fields].

The study aimed to determine the molecular targets of magnetic fields in living objects. Time-dependent effects of weak low-frequency magnetic field tuned to the parametric resonance for calcium ions were studied on model organisms (fish, whelk). The dynamics of Ca(2+)-dependent proteinase activity under the exposure to magnetic fields with given parameters was determined and minimal time of exposure in order to achieve inactivation of these proteinases was find out as well. As hyperactivation of Ca(2+)-dependent proteinases is a basis of degenerative pathology development the therapeutic potential of weak low-frequency magnetic fields enabling to modulate Ca(2+)-dependent proteinase activity is supported.

[Comparative Characteristics of the Lipid and Fatty Acid Status of Eyed-Stage Atlantic Salmon Embryos Reared in Natural and Artificial Environments].

The lipid status of Atlantic salmon (Salmo salar L.) embryos has been compared between embryos developing in incubator nests installed in the natural environment (UmbaRiver, Kola Peninsula) and those developing in a laboratory (in aquaria). The developmental stage of eye pigmentation selected for comparison is characterized by the highest sensitivity of the embryos to environmental factors. The content of certain classes of total lipids and fatty acids was different between the two groups of embryos, and the ratios between the relative content values for some of the compounds were different as well. The difference may be due to environmental factors (temperature, oxygen levels, running water in the nests, etc.) affecting the developing embryos, and they may determine the subsequent embryonic and postembryonic development of the fish.