Hormonal regulation of anabolic processes and of protein utilization efficiency in the early postnatal period

The levels of thyroid, pituitary and steroid hormones-thyroxine, triiodothyronine and 11-hydroxycorticosteroids in the blood serum, somatotropin in the pituitary, and processes of protein assimilation were studied in rats in the early postnatal period. The highest endogenous production of thyroxine, triiodothyronine and somatotropin was detected in 15-day-old rats. The highest level of protein utilization was detected in 7 to 15-day-old rats, followed by the lowering of the utilization on changing over to definitive nutrition. Endogenous production of the anabolic hormones thyroxine, triiodothyronine and somatotropin was found to correlate with a high level of protein utilization in rats within the first days of life after birth.     

Interaction of Lipophilic Conjugates of Modified siRNAs with Hematopoietic Cells In Vitro and In Vivo

Russian Journal of Bioorganic Chemistry - Delivery of siRNAs to blood cells is one of the most difficult tasks since there are no efficient and nontoxic methods of delivering nucleic acids to these...     

European checkerspots (Melitaeini: Lepidoptera,Nymphalidae) are not aposematic – the point of view of great tits (Parus major)

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Lectins of marine hydrobionts

Data from the literature and results of our research on lectins isolated from some kinds of marine hydrobionts such as clams, ascidians, sea worms, sponges, and algae are presented in this review. Results of comparative analysis of the basic physicochemical properties and biological activity of lectins isolated from various sources are discussed.     

Role of oxidative stress and mitochondria in onset of urinary bladder dysfunction under acute urine retention

Acute urine retention is a frequent complication in patients with benign hyperplasia of the prostate gland. According to studies made on experimental animals and people, it is accompanied by the deterioration of the bladder blood supply. This study attempts to explore the relationship of intramural blood flow, production of reactive oxygen species, and functional state of the bladder detrusor in modeling of acute urine retention in rats, as well as the impact of mitochondria-targeted antioxidants (which are supposed to alleviate the effects of oxidative stress induced by experimental ischemia) on these parameters. The study showed beneficial effects of mitochondria-targeted antioxidant SkQR1 in preventing damage of the bladder caused by acute urinary retention, which suggests the therapeutic use of this type of compounds for the treatment of ischemic abnormalities of the urinary bladder.     

Heat-induced activation of reducing properties of of sea water

It was shown using the Ellman's reagent that chloride and bicarbonate anions are the heat-induced reducing agents of sea-water, and their combined action is more than additive. Sulfate anions do not exhibit these properties. The influence of sea-water anions on the heat-induced production of hydrogen peroxide was studied by enhanced chemiluminescence in a peroxidase-luminol-p-iodophenol system. In NaCl and NaHCO3 solutions, at concentration and pH values equal to those of sea-water, the production of H2O2 upon heating increased, as compared with water, whereas sulfate anions depressed its formation. By using coumarin-3-carboxylic acid as a fluorescent detector of OH radicals, a substantial increase in the production of radicals in the presence of chloride and bicarbonate anions upon heating was shown. The effect is due to the electron donor properties of these anions, which lead to the decomposition of H2O2 with the formation of OH radicals. The results obtained were considered from the viewpoint of the equivalence of heat and electromagnetic radiation of an absolutely black body. It is supposed that the high-energy quanta of its spectrum lead to the dissociation of anions with the formation of a hydrated electron and radicals. Then a recombination of radicals with the formation of various molecular products takes place.     

Heat-induced formation of reactive oxygen species and 8-oxoguanine, a biomarker of damage to DNA

Heat-induced formation of 8-oxoguanine was demonstrated in DNA solutions in 10^–3 M phosphate buffer, pH 6.8, by enzyme-linked immunosorbent assays using monoclonal antibodies against 8-oxoguanine. A radiation-chemical yield of 3.7 × 10^–2 µmol J^–1 for 8-oxoguanine production in DNA upon γ-irradiation was used as an adequate standard for quantitation of 8-oxoguanine in whole DNA. The initial yield of heat-induced 8-oxoguanine exhibits first order kinetics. The rate constants for 8-oxoguanine formation were determined at elevated temperatures; the activation energy was found to be 27 ± 2 kcal/mol. Extrapolation to 37°C gave a value of k₃₇ = 4.7 × 10^–10 s^–1. Heat-induced 8-oxoguanine formation and depurination of guanine and adenine show similarities of the processes, which implies that heat-mediated generation of reactive oxygen species (ROS) should occur. Heat-induced production of H₂O₂ in phosphate buffer was shown. The sequence of reactions of thermally mediated ROS formation have been established: activation of dissolved oxygen to the singlet state, generation of superoxide radicals and their dismutation to H₂O₂. Gas saturation (O₂, N₂ and Ar), D₂O, scavengers of ¹O₂, O₂^–• and OH^• radicals and metal chelators influenced heat-induced 8-oxoguanine formation as they affected thermal ROS generation. These findings imply that heat acts via ROS attack leading to oxidative damage to DNA.     

Algae of Peter the Great Bay of the Sea of Japan as a source of lectins

Algae of Peter the Great Bay (Sea of Japan) were for the first time bioassayed as a source of lectins. From 28 algal species of three orders, only some extracts from brown (Phaeophyta) and red (Rhodophyta) seaweeds were found to cause agglutination of human erythrocytes. The hemagglutinating activity of extracts from three species of brown algae and the red alga Tichocarpus crinitus was caused by lectins; for a majority of extracts from the investigated algae, this activity was due to the presence of substances of non-lectin nature.     

Prolongation of oxidative stress by long-lived reactive protein species induced by X-ray radiation and their genotoxic action

Abstract The formation of long-lived reactive protein species of bovine serum albumin (BSA), ovalbumin, casein and casein hydrolyzate with a half-life of 3-5 hours was shown using chemiluminescence induced by X-ray radiation. It was found that long-lived reactive protein species are capable of generating reactive oxygen species (ROS) (H(2)O(2), OH(?), HO(2)(?, 1)O(2)) in the aquatic environment over a long period of time in vitro. The interaction of X-ray-irradiated BSA with DNA in vitro led to the formation of 8-oxoguanine (8-oxo-7,8-dihydroguanine), a biomarker of oxidative damage to DNA. Some natural antioxidants are effective scavengers of ROS (inosine, tryptophan, methionine and ascorbate). They protect DNA from the action of long-lived reactive protein species leading to ROS generation and the formation of 8-oxoguanine. The intravenous injection of X-ray radiation-induced, long-lived reactive protein species to rats, as well as the peroral and intraperitoneal administration of these products to mice, gave rise to cytogenetic injuries in the cells of their red bone marrow through the formation of micronuclei in polychromatophilic erythrocytes. The administration of the same natural antioxidants used for in vitro experiments soon after irradiation made it possible to effectively eliminate the genotoxic action of oxidative stress caused by radiation-induced, long-lived reactive protein species. Our data represent clear evidence that the oxidative damage to proteins induced by X-rays is directly involved in the induction of a response to DNA damage in rodents.