Vol 469, No 1 (2016)

A possible effect of nitric oxide (NO) on metabotropic glutamate receptor (mGluR) function in the amino acid afferent synapse was investigated in the isolated labyrinth of the frog Rana temporaria. The modification of the amplitude of responses of metabotropic glutamate receptor agonist trans-ACPD was analyzed during bath applied NO donor S-nitroso-N-acetyl-DL-penicillamine SNAP (0.1–100 μM) or nitric oxide synthase inhibitor L-NAME. It was shown that NO donor SNAP (1 μM) inhibited mGluR induced responses, and the inhibitor of NO-synthase L-NAME (100 μM) increased the amplitude of trans-ACPD evoked answers. The results suggest that NO can depress mGluR function due to modulation of functions of the endoplasmic reticulum channels.

We have found the physiological mechanism of intensification of the excessive fluid removal from the body under the action of glucagon-like peptide-1 and its analog exenatide. Under the water load in rats, exenatide significantly increased the clearance of lithium, reduced fluid reabsorption in the proximal tubule of the nephron and intensified reabsorption of sodium ions in the distal parts, which contributed to the formation of sodium-free water and faster recovery of osmotic homeostasis. Blocking this pathway with a selective antagonist of glucagon-like peptide-1 receptors slowed down the elimination of excessive water from the body.

Myelinated fibers and myelin-forming cells in the spinal cord at the L3–L5 level were studied in C57BL/6N mice that had spent 30 days in space. Signs of destruction of myelin in different areas of white matter, reduction of the thickness of myelin sheath and axon diameter, decreased number of myelin-forming cells were detected in “flight” mice. The stay of mice in space during 30 days had a negative impact on the structure of myelinated fibers and caused reduced expression of the markers myelin-forming cells. These findings can complement the pathogenetic picture of the development of hypogravity motor syndrome.

Adult males of the water vole have been found experimentally to recognize their neighbors and react to them differently depending on the degree of spatial proximity in nature. Most tensions (estimated by the number of aggressive acts in the encounters) were observed between distant neighbors (from neighboring settlements), which did not belong to the same groups with established hierarchy and a relatively reduced aggression. These are probably perceived as the most likely competitors (because of their spatial proximity). At the same time, male voles kept away from the obviously unfamiliar ones, though they do not express any apparent aggression.

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 most massive components of the microplankton were studied in the open sea waters for the first time at the end of the autumn season. It has been found that abundance of the virio- and bacterioplankton exceeded that observed in winter in the coastal zone. Against the background of a relatively uniform distribution of bacteria, the viral abundance and the lysis-mediated bacterioplankton death rate reached the maximum values in the most cold and salty waters of the northern sea areas.

The first results of the use of the Allium test for estimation of toxicity of bottom sediments in the Yenisei River and the effect of external γ-radiation under laboratory conditions are presented. The effect of stimulation of the onion root growth, i.e., the absence of toxicity was discovered in toxicological experiments using bottom sediments and under external γ-radiation. The stimulating effect of radiation on the growth of onion roots limits the use of the Allium test for testing samples from the Yenisei River ecosystem in the zone subjected to the impact of radioactive discharges from the Mining and Chemical Combine.

Uninfected donor T cells were treated in vitro by model immune complexes that contained either HIV or hepatitis C virus (HCV) antigens. Unlike HCV antigen-containing complexes, the immune complexes that contained HIV antigens have been shown to activate peripheral blood T cells of uninfected donors under in vitro conditions. Both the antiviral antibodies and HIV antigen were involved in the activation process. The unique properties of the immune complexes formed by HIV antigens and antiviral antibodies are believed to result from the virus-specific antibody properties and molecular conformation of the antigen–antibody complex.

It has been demonstrated that β-endorphin stimulates the zymosan-induced secretion of reactive oxygen species and suppresses the spontaneous production of IL-1β and IL-10 by murine peritoneal macrophages in vivo.