Nauchnye doklady vysshei shkoly. Biologicheskie nauki最新文献

The effect of gonadectomy and sex-steroid hormones treatment on functional interhemispheric asymmetry to the reaction of pain cry avoidance of another species (emotional reactions) and motor and exploratory activity of open-field behavior in Wistar rats of 3 months old has been investigated. A spreading depression technique for hemisphere inactivation has been used. The hemispheric asymmetry of the reactions in intact rats was characterized by sex dimorphism; the left hemisphere dominated to a great extent in males than in females under the control of emotional reactions; in motor and exploratory activity in open-field behavior of rats the left hemisphere dominated in males and the right one--in female. In both sexes the neonatal gonadectomy levelled the interhemispheric differences in reactions under investigation. The following treatment of females with estradiol and males with testosterone didn't restore the asymmetry. After the castration at the age of 3 months the correlation between the size and direction of interhemispheric differences became reverse. The treatment of females with testosterone and males with estradiol both castrated in adulthood restored the interhemispheric asymmetry in males and had no effect in females. The treatment of intact rats with hormones of opposite sex led to the enhancement of left hemisphere dominance in motor and exploratory activity in males and levelled the asymmetry in females. It has been shown that in adult rats sex-steroids effect predominantly the right hemisphere.

The action of metal ions which are present in nutritious medium on the synthesis of extracellular enzymes by sporulating bacteria is analysed. An important role of these ions in post-secretory modification of protein molecules and formation of functionally active molecules of enzyme is shown. The effect of metal ions on some cell envelope properties and extracellular enzyme secretion is under discussion.

The preparation of Hypericum perforatum L. has been shown to possess radioprotective properties. The effect found depends on the time of its taking and its concentration. A statistically reliable protection of marrow and the mucus of the thin intestine of mice from X-rays is observed.

The structure gene of extracellular alkaline ribonuclease Bacillus intermedius (binase) has been cloned in E. coli cells in composition of pMT 316 plasmid carrying the inhibitor gene (barstar of barnase--binase structure homologue. The possibility to use such vector has been proved during the barstar action on binase catalytic activity. Using biochemical immunochemical analysis the expression of binase gene in E. coli cells has been confirmed. The recombinant clone E. coli which contains both plasmids simultaneously--carrying gene for barster and for benase has been produced. The given vector is suggested to be used for cloning of inhibitor gene to obtain a viable producer of alkaline intracellular ribonuclease.

The increase of cytochrome P-450 by 34% and its catalytic activity with substrate amidopyrine by 57% as compared with control has been shown under hypoxia (0.029 MPa, 1 h). Hyperoxia (0.2 MPa, 1 h) increases the metabolism of amidopyrine by 148%, benzo[a]pyrene by 158% and aniline by 114% and consecutive affection of hypoxia and hyperoxia--by 247, 45 and 138% correspondingly at fixed cytochrome P-450 amount in both series. The amount of diene conjugates and Schiff's bases under hypoxia increases by 40 and 69% correspondingly, the activity of SOD and catalase decreases by 25 and 23%. The activity of hyperoxia raises the diene conjugate content by 19% at all this SOD activity increases by 95%. Consecutive affection of hypoxia and hyperoxia increases the level of diene conjugates and Schiff's bases by 26 and 23% correspondingly, without changing SOD and catalase activity. The relative microsomal viscosity of lipid layer and zones of enzyme-lipid contacts decreased by 20 and 24% under hypoxia, but under hyperoxia and consecutive affection and hypoxia and hyperoxia it increases by 29-28% and 56-40% correspondingly.

The biological action of chromium in the human or animal organism depends on valency: normal physiological activity is displayed at the expense of CrIII, but toxic activity is more characteristic of CrVI. In the digestive tract and pulmonary tissue CrVI may restore in CrIII.

A sequence of biochemical reactions in yeast from moment of RNAse interaction with cell membrane to cell division has been studied. RNAse addition in growth medium causes the increase of Ca2+ entering rate in cells in 2.4 times. Under this condition the increase of membrane enzyme adenylate cyclase correlating with the growth of cAMP content in cell and rise of cAMP-dependent protein kinase activity have been observed. A hypothetic scheme of cellular response on the RNAse effect is suggested.

New antibiotic-resistant strains Bacillus intermedius--producers of phosphohydrolase and protease have been obtained and characterized. Strain S 19 is the more active producer of extracellular enzymes. Autotrophic mutants obtained on its basis possess reduced activity of phosphohydrolase.

The effectiveness of interferon (IFN) action depends not only on the type of IFN but also on the sensitivity of target cells to IFN. Revealing the reasons of different sensitivity of cells to IFN is of significant importance for understanding the mechanisms of cell reaction regulation. The review presents the principle historical stages of study of cell resistance to IFN, some aspects of cell insusceptibility to antiviral and antiproliferative action of various types of IFN are considered. Types of cell resistance to specific IFN effects have been determined. The mechanisms of development of cell resistance and possibilities in correction of cell insusceptibility to IFN are discussed.