A simulated geomagnetic storm unsynchronizes with diurnal geomagnetic variation affecting calpain activity in roach and great pond snail.

It has been suggested that geomagnetic storms could be perceived by organisms via disruption of naturally occurring diurnal geomagnetic variation. This variation, in turn, is viewed by way of a zeitgeber for biological circadian rhythms. The biological effects of a geomagnetic storm, therefore, could depend on the local time of day when its main phase occurs. We have assessed calpain activity in tissues of roach (Rutilus rutilus) and great pond snail (Limnaea stagnalis) after exposure to a simulated geomagnetic storm, reproduced at different times of day, in order to evaluate this hypothesis. Significant decrease in calpain activity was observed in organisms exposed to the simulated geomagnetic storm whose main phase, and initial period of a recovery phase, did not coincide with the expected peak of diurnal geomagnetic variation. The results obtained are considered an experimental confirmation of the aforementioned hypothesis. Improvement of a correlative approach for the assessment of biological effects of geomagnetic activity can be achieved by considering information on the synchronization of geomagnetic storm's main phase with diurnal geomagnetic variation.

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.

[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.

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.

[BIOCHEMICAL RESPONSE OF BLUE MUSSELS MYTILUS EDULIS L. FROM THE WHITE SEA TO RAPID TEMPERATURE CHANGES].

The effect of a rapid temperature change on the biochemical status of blue mussels Mytilus edulis L. from the White Sea was studied under conditions of aquarium experiment. It is shown that modifications of the composition of reserve and structural lipids and their fatty acids, of the activity of lysosomal enzymes (ß-glucosidases, cathepsins B and D), of calcium-dependent proteases of cytocol (calpains) and of the enzyme of the second phase of biotransformation of xenobiotics - glutathione-S-transferase, reflect an unspecific compensatory reaction of bivalves to stress action of environmental factors and indicate reconstruction of blue mussel metabolism as early as within first hours of temperature change. The initial high level of glutathione-S-transferase activity in control blue mussels as well as an increase of glutathione concentration in the course of experiment may facilitate successful exit of mussels from the state of reduced metabolism.

[Calpains and their endo- and exogenous regulators in various neurodegeneration models].

On the basis of experimental series with murine models there was obtained the evidence on calcium-dependent protease activity changes in rat brain at induced neurodegeneration. The properties of the proteolytic and regulatory components of calpain system under the effect of neurotoxic stimuli--amyloid beta-peptide or glutamate--were characterized; the basic endogenous regulatory mechanisms of calcium-dependent proteolysis modulation were determined as well. Neuroprotective properties of exogenous calpain regulators differing in the mechanisms of action (sex steroids, calcium regulators) were tested on studied neurodegeneration models.

[The effect of weak low-frequency magnetic fields on the intracellular calcium-dependent proteinases of fish].

The in vivo and in vitro effects of weak, low-frequency magnetic fields with resonance parameters for calcium ions upon intracellular calcium-dependent proteinases (calpains) in the crucian carp (Carassius carassius (L.) and roach (Rutilus rutilus (L.) were studied. It has been revealed that the impact of a weak low-frequency magnetic field leads to considerable decrease in the activity of calpains in the fish skeletal muscles and brain.

[Calpain system dysregulation in rat brain at beta-amyloid-induced neurodegeneration].

Experimental evidences of calcium-dependent proteolysis dysregulation in brain of murine model of Alzheimer disease were obtained. Experimental treatment consisted in intra-hippocampal injection of amyloid beta-peptide (AP1-40) promoted activation of main calpain forms in murine brain along with decrease incontent of natural calpain inhibitor, calpastatin. As a result of prognostic experiment on the correction of neurodegeneration induced in murine the neuroprotective properties of steroid hormone estradiol were confirmed and one of the possible protective action mechanisms was suggested. Obtained results allow considering both biochemical modifications in protein facilities of pathology-affected brain and the mechanisms of neurodegeneration and neuroprotection.

[Modulation of Ca(2+)-dependent proteinase activity in invertebrates and fish under the action of weak low-frequency magnetic fields].

The effect of weak low-frequency magnetic field on intracellular Ca(2+)-dependent proteinases (calpains) of fish and invertebrates was studied in in vivo and in vitro experiments. It has been found that intravital effect of weak low-frequency magnetic field tuned to the parametric resonance for Ca2+ ions led to a significant decrease in calpain activity in examined animals. It was shown that preparations of Ca(2+)-dependent proteinases from invertebrates and fish have been also substantially inactivated at the effect of indicated factor. Observed phenomenon is in the correspondence with an interference model of the impact of weak low-frequency magnetic field on the biological objects.

[Proteases of calpain family in water invertebrates and fish].

The activity of Ca2+-dependent proteases, or calpains (EC 3.4.22.17), in a wide range of aquatic invertebrates (Oligochaeta, Hirudinea, Crustacea, Insecta, Gastropoda, Bivalvia) and vertebrates (Osteichthyes) was estimated. Detected molecular properties ofcalpains from the tissues of different species allow considering the complication of their structural organization and regulatory mechanisms between invertebrates and vertebrates in comparative-evolutionary aspect. Certain conclusions can be drawn about changes in the functional role of this proteolytic system in the cell metabolism.

[Correlation of intracellular Ca(2+)-dependent proteinase activity and the content of membrane lipid components in mussel, Mytilus edulis, under heavy metal accumulation].

Correlation of calpain activity level and some membrane lipid component contents in organs of mussels, Mytilus edulis L., was shown in aquarial experiment on the study of mussel response reactions on the exposure of different levels of copper and cadmium. The correlation observed possibly could be explained by the effector role of membrane lipid components (arachidonic acid, phosphatidylinositol) on Ca(2+)-channels. Thus, the correlation between tissue lipid composition and protein functional activity was demonstrated with intracellular Ca2+ level as a key member.

[Proteinases of the calpain family: structure and functions].

Results of studies presented in recent papers and personal data related to investigation of structure, classification, phylogeny of calcium-dependent peptidases or calpaines have been analyzed. The most extensively studied functions of calpains in cell activity have been examined. Some not yet resolved questions concerned with the biological role of a great number of proteins of the calpain family have been defined.

[Calcium-dependent proteinases of some invertebrates and fishes].

In comparative-evolutionary aspect, the experimental data are considered about activity, biochemical properties, and peculiarities of structural organization of proteins of the calpain family in some invertebrates and fishes. Peculiarities of calpain-like proteins of invertebrates--the predecessors of calpains of higher animals are revealed. By the example of the studied taxons, there is traced complication of the structural organization and mechanisms of control of the calpain activities, which reflects stages of molecular evolution of the protein family.

[Handling and maintenance of gerbils during the spacecraft Foton-M3 mission].

Pressurized low-sized module Kontur with an independent life support system (LSS) was developed by the Institute of Biomedical Problems cooperatively with the Special Design Bureau of Experimental Equipment to house gerbils (Meriones unguiculatus) aboard robotic technology-purpose spacecraft. Design of the module precludes pollution of the environment The fully equipped module weighs 69 kg; average daily power consumption is 62 watts. The environmental parameters for 12 animals flown on Foton-M3 in the period of September 14-26, 2007 were controlled within the following ranges: pO2 - 143-156 mm Hg, (mean 150 mm Hg), pCO2 - 0.76 mm Hg maximum (mean 0.64 mm Hg), temperature - 23-28 degrees C (mean 26.7 degrees C), relative humidity - 29% and 57% at the beginning and end of the flight, respectively (mean 39%). The animals consumed the palletized food prepared of natural products with a moisture content of approx. 20%. The day-night periods were 12 hrs. long. The daytime video recording of the animals went on continuously in the throughout the flight. The experiment showed that the module meets the requirements of experiments with mammals aboard returnable robotic spacecraft and piloted space stations. At the moment, the model is being redesigned for a 30-day BION-M1 mission.

[Development of chow for Mongolian gerbils suitable for the conditions of space flight].

One of formidable issues of experiments with animals in space flight is water supply. For Mongolian gerbils (Meriones unguiculatus), classed as cricetid rodents, water in chow is enough. These animals are a new object for space biology. Our purpose was to compose a full-value formula and design a chow making and long-term storage technology to provide Mongolian gerbils for in microgravity. The chow is required to have a 28-d shelf life. To assess the chow suitability on autonomous space fight, the gerbils we house in a cage with the geometry reproducing the current design of the future space animal module. The assessment was performed with adult male gerbils weighing 50.5 +/- 3.4 g on the average. The animals ate up 40.1 +/- 3.9%, i.e. less than 50% of the feed all through the period of experiment. However, by the end of the experiment the body mass and exterior remained essentially unchanged In was concluded that the chow formula can be prescribed to Mongolian gerbils housed in self-contained modules.

[Physiologically active argon-based gas mixtures as a means of creating fire-safe gaseous environments in pressurized modules of varying purpose].

Development of acute hypoxic hypoxia in consequence of fire in various pressurized modules was studied. The investigation was aimed to look into the effects of inert argon and dramatic oxygen reduction in gaseous environment on animals (Wistar rats, mice c57bl/6, balb/c and f1cbaxbalb/c hybrids, Japanese quail embryos) and microorganism (Escherichia coli strains k-12 jf 238 and k-12 jm 83). Also, inflammability of some widely used materials was assessed in order to provide inputs to developers of fire-safe gaseous mixtures for pressurized habitats. It was shown that argon is favorable to survivability of animals and to maintenance of a high level of oxygen consumption. Gaseous mixtures with oxygen content less than 15 volume % suppressed burning of selected materials. Results of the investigation offer possibilities for designing new hypoxic fire-safe gas mixtures that will provide adequate human performance and ensure survival in extreme situations.

[Impact of hypoxic gas mixtures on embryogenesis of the Japanese quail].

Avian embryogenesis is of great interest to investigators, as the germ developing outside mother's body, is capable to react briskly to any alteration in the outer world. The paper present experimental evidence of the impact of oxygen with physical and chemical properties modified by short-cycle no-heating adsorption (SNA) in a hypoxic gas mixture (10% O2) on the early embryogenesis of the Japanese quail. Low concentrations of oxygen are known to be a dramatically disturbing factor for embryo's morphology. It was demonstrated experimentally that four days before incubation bird are highly sensitive to oxygen deficiency which is responsible for developmental abnormalities. The use of SNA oxygen reduced the frequency of pathologies in the Japanese quail germs as compared with their controls incubated in gas environment containing medical oxygen generated by low-temperature rectification.