Zhurnal evoliutsionnoi biokhimii i fiziologii最新文献

In representatives of class of birds (pigeons Columba livia) using electrophysiological methods for the first time there was performed analysis of effects of microinjections into the hypothalamic ventrolateral preoptical area (VLPA) of antagonists of the adenosine A(2A) type receptors on the sleep-wale cycle under natural conditions and on realization of somnogenic effect of Heat shock protein 70 kDa (Hsp70). The following has been established: 1) microinjections of adenosine A(2A) receptors antagonist (8-(3-Chlorostyryl) caffeine (ChC)) into VLPA at the beginning of inactive phase of the 24-h period dose-dependently increase wakefulness and suppress sleep; 2) microinjections of Hsp70 into VLPA produce somnogenic effect manifested as an increase of the total time of slow sleep (SS) and enhancement of mechanisms of initiation and maintenance of SS; 3) block of adenosine A(2A) receptors by ChC suppresses the Hsp70-induced SS. The obtained data indicate participation of adenosine A(2A) receptors located in VLPA in modulation of the sleep-wake cycle under natural conditions and in realization of somnogenic effect of Hsp70 in pigeons. A hypothesis is put forward that the somnogenic action of Hsp70 is mediated by modulating effect of this chaperone on function of adenosine proteins-receptors.

The spatial specificity of auditory approaching and withdrawing aftereffects was investigated in an anechoic chamber. The adapting and testing stimuli were presented from loudspeakers located in front of the subject at the distance of 1.1 m (near) and 4.5 m (far) from the listener's head. Approach and withdrawal of stimuli were simulated by increasing or decreasing the amplitude of the wide-noise impulse sequence. The listeners were required to determine the movement direction of test stimulus following each 5-s adaptation period. The listeners' "withdrawal" responses were used for psychometric functions plotting and for quantitative assessment of auditory aftereffect. The data summarized for all 8 participants indicated that the asymmetry of approaching and withdrawing aftereffects depended on spatial localization of adaptor and test. The asymmetry of aftereffects was largest when adaptor and test were presented from the same loudspeaker (either near or far). Adaptation to the approach induced a directionally dependent displacement of the psychometric functions relative to control condition without adaptation and adaptation to the withdrawal was not. The magnitude of approaching aftereffect was greater when adaptor and test were located in near spatial domain than when they came from far domain. When adaptor and test were presented from the distinct loudspeakers, magnitude approaching aftereffect was decreasing in comparison to the same spatial localization, but after adaptation to withdrawal it was increasing. As a result, the directionally dependent displacements of the psychometric functions relative to control condition were observed after adaptation as to approach and to withdrawal. The discrepancy of the psychometric functions received after adaptation to approach and to withdrawal at near and far spatial domains was greater under the same localization of adaptor and test in comparison to their distinct localization. We assume that the peculiarities of approaching and withdrawing aftereffects observed reflect their spatial specificity. It is possible that spatial peculiarities of approaching and withdrawing aftereffects can be associated with specialized mechanisms for analysis of motion at the different distance from subject.

The distribution of the immunoreactivity for gamma-aminobutyric acid (GABA), choline acetyltransferase (ChAT), calcium-binding proteins (CaBPr) and histochemistry of cytochrome oxidase activity (CO) was studied in turtles (Testudo horsfieldi, Emys orbicularis) isthmal complex of visual nuclei. Magnocellular nucleus (IMc) was shown to reveal mainly the strongly stained GABA-, parvalbumin (PV)-ir neurons and CO-positive cells, as well as variable both in number and degree of intensity of ChAT-, cal- bindin (CB)-, and calretinin (CR)-ir cells. After the local tracer injection into the optic tectum GABA-ir neurons containing also retrograde label were found in IMc. The most caracteristic of the parvocellular nucleus (IPc) was the content of strongly stained ChAT-ir neurons, dense GABA-ir and CO-active terminal fields, as well as the neurons variable by the amount and the degree of immunoreactivity for CaBPr and GABA. Principal similarity in these features in the turtle IMc and IPc and of those in the avian isthmal nuclei of the same name allows suggesting their homology and consequently the same participation in selective processing of the visual information flow. The comparison with lower vertebrates confirms the evolutionary conservatism of visual isthmal complex among vertebrates and the existence of its progressive differentiation in the process of evolution.

There are obtained data indicating that morphogenesis and, probably, formation of structurally functional interaction of the CART- and dopaminergic neurons occur as early as during embryonic development. Meanwhile development of the AGRergic system and formation of its structural and functional communications are observed in the course of postnatal development of rat. Analysis of literature and re- sults of our own investigation show that differentiation of dopaminergic neurons in hypothalamus and midbrain occurs on the background of development of CARTergic neurons and in the absence of AGRP. Taking into account our data on activating action of the CART-peptide and inhibitory effect of AGRP on dopaminergic brain neurons, we believe that the leading component at formation of functional interactions of these systems is the later maturing AGRPergic system.

Seasonal changes of relative blood reticulocyte counts, free plasma hemoglobin and mechanical erythrocyte resistance were studied in the long-tailed ground squirrel (Citellus undulatus), under different functional conditions (winter hibernation, forced arousal in winter, and summer activity). A significant increase in reticulocyte counts in the ground squirrel blood was observed in April and October, indicating enhancement of erythropoeisis. This conclusion is also confirmed by a significant increase in free plasma hemoglobin at these periods. It has been also shown that erythrocytes of hibernating and forcibly awaken winter ground squirrels have a significantly lower mechanical resistance in comparison with those of active summer animals. The obtained data indicate that during the periods preceding the onset of winter hibernation and transition to summer activity there occurs a seasonal replacement of the erythrocyte pool by a pool more adapted to performance of functions in the novel functional state of the animal-hibernator.

Peculiarities of the state of lipid metabolism and of processes of lipid peroxidation--the antioxidant protection have been considered in female representatives of the native and alien population of Tofalaria in the age aspects. The obtained data indicate specificity of changes of level of parameters lipid metabolism not only in response to duration of effect of climatic factors, but also depending on belonging to different ethnic groups. Thus, in girls of the natural population of Tofalaria there is noted activation of adaptational-compensatory processes as compared with the alien ones, which is expressed as a significant decrease of atherogenic blood fractions and the general activation of the system of antioxidant protection. However, with age, in both ethnic groups a change of character of reactions of lipid peroxidation and lipid metabolism is noted, which is more expressed in the alien population.

Analyzing existing literature sources and his own experimental data, the author has concluded that (i) regulatory peptides arise solely as a result of cleavage of protein precursors, but not by non-ribosomal synthesis; (ii) the peptide regulation of physiological functions emerged as a part of autocrine regulation system almost simultaneously with life itself; peptide paracrine regulation appeared in the colonial prokaryotes, and peptide endocrine regulation in the multicellular eukaryotes; (iii) the regulatory peptides and their receptors could occur either sequentially (in any order) or simultaneously; (iv) conservatism of the primary structure of regulatory peptides is not significantly different from that of proteins; (v) the regulatory peptides are presented in the most evolutionarily ancient species wider than specialists think.

Regularities of the appearance of family have been analyzed in the superfamily of bees. It is shown that conversion of family in the highly organized eusocial bee species into the biological unit is coupled to perfection of instincts of care of offspring of the female-founderess and to an increase its lifespan duration at enhancement of various forms of domination. There is substantiated the concept that development of offspring of the dominating females under similar conditions ruling out intranest competition as well as enhancement of interconnection and interdependence between members of the family has led to the appearance of family selection.

Effect of hypoxia (diapason of 0.57-8.17 mg O2 l(-1)) on functional characteristics of nucleated erythrocytes of the benthonic marine fish Scorpaena porcus L. was studied under conditions in vivo and in vitro. It has been established that characteristic of cellular system of this species is a balanced unhibition of membranous and metabolic functions under conditions of external deficit of oxygen (experiments in vivo). This is expressed in the ability of cells to maintain within norm the intracellular ATP concentration and transmembrane gradients for Na+ and K+ with low activities of Na+, K(+)-ATPase and hexokinase. This phenomenon seems to be based on the process of a decrease of the number of functioning ion channel at the level of the cell cytoplasmic membrane; this process reduces energy expenditure for maintenance of cationic gradients (the phenomenon of metabolic arrest). The same is also indicated by an increase of intensity of fluorescence of FDA and R123 in the scorpaena erythrocytic suspensions in hypoxia (experiments in vitro). Mechanisms underlying this phenomenon are discussed.

The functional state of the adenylyl cyclase signaling system (ACSS) and its regulation by hormones, the inhibitors of adenylyl cyclase (AC)--somatostatin (SST) in the brain and myocardium and 5-nonyloxytryptamine (5-NOT) in the brain of rats of different ages (5- and 7-month-old) with experimental obesity and a combination of obesity and type 2 diabetes mellitus (DM2), and the effect of long-term treatment of animals with intranasally administered insulin (II) on ACSS were studied. It was shown that the basal AC activity in rats with obesity and DM2 was increased in the myocardium, and to the lesser extent in the brain, the treatment with II reducing this parameter. The AC stimulating effects of forskolin are decreased in the myocardium, but not in the brain, of rats with obesity and DM2. The treatment with II restored the AC action of forskolin in the 7-month-old animals, but has little effect on it in the 5-month-old rats. In obesity the basal AC activity and its stimulation by forskolin varied insignificantly and weakly changed in treatment of animals with II. The AC inhibitory effects of SST and 5-NOT in the investigated pathology are essentially attenuated, the effect of SST to the greatest extent, which we believe to be associated with a reduction in the functional activity of Gi-proteins. The II treatment of animals with obesity and with a combination of obesity and DM2 restored completely or partially the AC inhibiting effects of hormones, to the greatest extent in the brain. Since impaired functioning of ACSS is one of the causes of the metabolic syndrome and DM2, their elimination by treatments with II can be an effective approach to treat these diseases and their CNS and cardiovascular system complications.