[Nuclear ribonucleoproteins containing pro-mRNA. XIV. Structural study using ethidium and fluorescamine]. / Iadernye ribonukleoproteidy, soderzhashchie pro-mRNK. XIV. Issledovanie struktury s ispol'zovaniem étidiia i fluoreskamina.

Nuclear 30S RNP particles were studied by means of fluorescence techniques. It's shown that fluorescamin interacts with NH2-groups of protein molecule. As a result, covalent fluorescent label is formed. Quantum yield (rho), fluorescence spectra, lifetime of excited state (tau) and polarization of fluorescamin complexes with 30S particles were studied. Excitation spectra have their maximum at 395 nm, and fluorescence spectrum at 480 nm. These figures correspond to spectra of fluorescamin complexes with NH2-groups of lysine. Mean quantum yield (rho = 0.27) and lifetime of excited state of fluorescence (tau = 7.8 nsec) were measured. It's shown that fluorescamin forms two types of fluorescent complexes in 30S particles. These complexes differ only by their rho(rho1 = 0.11, rho2 = 0.30) and rho(rho1 = 3.6 nsec, rho2 = 10.0 nsec) by 2.7 times. Migration radius between fluorescamin bound to protein and ethydium bromide adsorbed on double-stranded regions of pre-mRNA in RNP-particles was measured. It's equal to 32 A. Adsorbtion isotherms of ethydium bromide were measured by fluorescence in 0.1 and 0.4 M NaCl. Data obtained showed that 6% of pre-mRNA in 30S particles bound the dye as a strong complex, i. e. this part of pre-mRNA is double-stranded. RNase treatment of RNP had no effect on this value. But the increase of NaCl concentration up to 0.4 M caused the dissociation of protein subunits to some extent followed by appearance of up to 40% free NH2-groups interacting with fluorescamin. Measuring of energy migration from fluorescamin to ethydium bromide showed that double-stranded pre-mRNA regions strictly bound to protein sticked out from RNP particle at a distance of about 27 A. The increase of NaCl concentration up to 0.4 M leads to disruption of this strict bond of double-stranded regions with protein. As a result, these regions of pre-mRNA become labile and move away from the RNP particle at more than 30 A. According to theoretical calculations, there is about 1--2 pre-mRNA hairpins (18--9 base pairs respectively) per one 30S particle.

[The Drosophila mobile element jockey, being a typical LINE, is transcribed from the internal promoter by RNA polymerase II]. / Mobil'nyi élement drozofily zhokei, iavliaiushchiisia tipichnym LINE, transkribiruetsia s vnutrennego promotora RNK-polimerazoi II.

Two polyadenylated transcripts of the jockey are detected at different stages of Drosophila melanogaster ontogenesis and in the cell culture. They have the same length as complete and deleted copies of jockey and correspond to the DNA strand containing open reading frames coding for polypeptides which are homologous to retroviral RNA-(DNA)-binding proteins and to their reverse transcriptases. The results of the experiments, where transcription was inhibited with alpha-amanitin in vivo, indicate that jockey is transcribed by RNA polymerase II. The analysis of expression of CAT constructions made on the basis of jockey, and the detection of a fixed site for transcription initiation in jockey genomic and transfected copies have shown that jockey transcription is controlled by an internal promoter located not farther than 12 nucleotides from the beginning of the element. Such an inward location of the promoter allows it to be preserved in replication via reverse transcription and accounts for the distribution of jockey and probably other LINEs throughout the genome. This is the case of the first internal promoter described for RNA polymerase II. The comparison of starting sequences of LINEs in Drosophila makes it possible to detect core sequences of such a promoter.

[Interaction of products of su(Hw) and su(f) genes with MDG4 region regulating its transcription suppresses mutations in Drosophila caused by insertion of this gene]. / Vzaimodeistvie produktov genov su(Hw) i su(f) s oblast'iu MDG4, reguliruiushchei ego transkriptsiiu, supressiruet mutatsii u drozofily, vyzvannye vstraivaniem étogo gena.

The mdg4 (gypsy) mobile element of Drosophila contains two closely situated regions binding to proteins from nuclear extracts. One of these is an imperfect palindrome having homology with the lac operator of Escherichia coli, the other contains a reiterated sequence (5'PyPuTCTGCATACTPyPy) homologous to the octamer which is the core of many enhancers and upstream promoter elements. The transient expression of deletion mutants has shown that these DNA regions are negative and positive regulators, respectively, of mdg4 transcription. As was demonstrated earlier, mutations induced by the presence of mdg4 at different loci are suppressed, owing to either repression or activation of mdg4 transcription in Drosophila lines carrying unlinked mutations in su(Hw) or su(f) genes. We have shown that binding to a negative regulator (silencer) is weakened in nuclear extracts isolated from cell lines carrying su(f) mutations which activate mdg4 transcription; therefore, the su(f) gene codes for a protein capable of mdg4 repression. Furthermore, binding to a positive regulator is weakened in nuclear extracts isolated from cell lines carrying su(Hw) gene mutations which decrease the level of mdg4 transcription; hence, the su(Hw) gene encodes a protein which activates mdg4 transcription.

[Metabolism of homocarnosine and gamma-amino butyric acid in different regions of rat brain under hyperoxia]. / Obmen gomokarnozina i gamma-aminomaslianoi kisloty v razlichnykh otdelakh mozga krys pri giperoksii.

The content of homocarnosine, GAMA, histidine, glutaminic acid and activity of glutamate decarboxylase were studied in four regions of rats brain: cerebral hemispheres, midbrain, diencephalon and cerebellum, in norm and under hyperoxia. A considerable decrease in the content of homocarnosine, GAMA and histidine is observed in all the studied regions of the rat brain in the convulsion stage of oxygen poisoning. A decrease in the glutamate decarboxylase activity is the reason for a drop in the GAMA content. Homocarnosine in the brain is bound functionally with the GAMA level.

[Polyamine contents in the brain and liver of rats during acclimatization to the cold]. / Soderzhanie poliaminov v mozgu i pecheni krys v protsesse akklimatsii k kholodu.

The content of polyamines, spermidine and spermine in the brain and liver was studied in rats during acclimation to cold for 45 days. In the brain the amount of spermidine after one and three days does not change, on the 7th and 15th day it decreases and by the end of acclimation returns to the control value. The content of spermine lowers by 29% by the third day of acclimation and on the 7th day returns to the initial level and does not change up to it end. In the liver the amount of spermidine rises significantly on the third day of acclimation, returns to the control level on the 7th day and then its amount falls. The content of spermine is increased in all period of acclimation and only by the 45th day it returns to its initial level.

[Homocarnosine in the brain of rats during cold adaptation]. / Gomokarnozin v golovnom mozgu krys pri kholodovoi adaptatsii.

24-hr effect of 2 degrees C-cold decreased the content of homocarnosin by 47.5% in the rat brain. 3-day effect decreased it by 51.2% and 7-day action decreased it by 62.2%. In cold-adapted rats (45 days) the homocarnosin content in the brain remains decreased by 56.5% and practically does not differ from the control level on the 7th day of cold-adaptation.

[Content of N-acetyl-L-asparate, N-acetyl-L-glutamate and N-acetyl-L-aspartyl-L-glutamate in the brain of mammals at increased oxygen tension]. / Soderzhanie N-atsetil-L-aspartata, N-atsetil-L-glutamata v mozge mlekopitaiushchikh pri povyshennom davlenii kisloroda.

The contents of N-acetyl-l-asparate and N-acetyl-l-glutamate, N-acetyl-l-aspartyl-l-glutamate were studied in the brain of rats of six age groups: newborns and on the 1st, 7th, 14th, and 30th day after birth. The amount of N-acetyl-l-asparate, N-acetyl-l-glutamate and peptide in the rat brain for 30 days of the postanal life is 8, 3.5 and 14.3 times as high, respectively. Under hyperoxic the amount of peptide, N-acetyl-l-asparate and N-acetyl-l-glutamate in the brain of rats of all the examined groups decreases especially in 14-, 21- and 30-day animals.

[Homocarnosinase activity in the rat brain areas kidneys under different states of hyperbarooxygenation]. / Gomokarnozinaznaia aktivnost' v otdelakh golovnogo mozga i pochkakh krys pri raznykh rezhimakh giperbarooksigenatsii.

The homocarnosinase activity in different brain areas and kidneys of the normal rats and under different conditions of hyperbarooxygenation are determined. The highest activity of this enzyme is observed in cerebellum. The high homocarnosinase activity is typical of kidneys as well. The action of oxygen in a dose of 0.425 MPa for 60 min (in the absence of convulsions) increases the homocarnosinase activity in the cerebral hemispheres by 18.6%, in the midbrain by 18.6%, in midbrain and diencephalon--by 56.5%, and in the medulla oblongata--by 40.6%. The homocarnosinase activity in the cerebellum decreases by 16.7%, in kidneys--by 18.5%. At the convulsive stage of oxygen intoxication caused by the effect of 0.7 MPa dose of oxygen the homocarnosinase activity in cerebral hemispheres rises by 158.5%, in the midbrain and diencephalon--by 141.5%, in the medulla oblongata by--161.1%. Under the same conditions homocarnosinase activity in the cerebellum is unchanged as compared with the control.

[Monoamine oxidase activity in the brain during adaptation to cold and simultaneous exposure to cold and hyperbaric oxygenation]. / Aktivnost' monoaminoksidaz mozga pri kholodovoi adaptatsii i sovmestnom deistvii kholoda i giperbarooksigenatsii.

One--day cold exposure decreases the monoamine oxidase type A activity by 52--54% (serotonin and noradrenaline substrates); the monoamine oxidase type B activity by 14%. Three--day cold exposure leaves the monoamine oxidase type B activity unchanged and decreases the monoamine oxidase type A activity by 29--32%; the enzyme of the latter type acquires the ability for deamination of glucosamine, putrescine and GABA. Under cold adaptation (45 days, 2 degrees C) the monoamine oxidase type A activity remains reduced as on the 3rd day, the type B activity decreases by 19%; enzyme substrate specificity does not change at all. Preliminary cold adaptation prevents alteration of the monoamine oxidase substrate specificity under hyperbaric oxygenation.

[Polyamines and activity of acid peptide-hydrolases in hyperoxia]. / Poliaminy i aktivnost' kislykh peptidgidrolaz pri giperoksii.

The content of spermidine and spermine polyamines in the rat brain under hyperoxic convulsions and four hours after convulsions decreases sharply. The intraperitoneal administration of polyamines before hyperbaric oxygenation decreased the rate of development of hyperoxic convulsions in rats. In the model experiments polyamines prevented changes in the acid peptide-hydrolase activity in the lysosomal and soluble fractions, which occur under hyperoxia.

[Mechanisms of the effect of cold adaptation on the resistance to hyperoxia]. / O mekhanizmakh vliianiia adaptatsii k kholodu na ustoichivost' organizma k giperoksii.

Hyperoxia after 3-day exposure at 2-4 degrees C induces more obvious disturbance of metabolites in rats than each of the factors separately. Along with decreased arginase activity in the brain and liver by 23 and 32% resp., the urine content decreases as well by 36 and 37% resp. Resistance of these animals against hyperoxia is reduced. But a preliminary 45-day cold-adaptation at 2-4 degrees C leads to a considerable activation of liver arginase and to increased content of urine in brain and liver by 32 and 30%, resp. The activation of arginase--urine system preserves under hyperoxia: the cold-adapted animals prove more resistant against hyperoxia effect. The above dynamic changes seem to be one of possible unspecific biochemical mechanisms of increasing the organism resistance against effects of extreme factors.

[Monoamine oxidase activity and brain levels of histamine and polyamines in various extreme exposures]. / Monoaminoksidaznaia aktivnost' i soderzhanie gistamina i poliaminov mozga pri nekotorykh ékstremal'nykh vozdeistviiakh.

The activity and kinetic properties of monoaminoxidase, the level of histamine and polyamines are studied under three extreme factors--hyperoxia, hypoxia and cold stress. The similarity of the metabolic responses of the organism to the investigated extreme factors is shown. All studied parameters indicate that the selected regime of hyperoxia has the most negative effect on the organism; hypoxia has the slightest effect and cold stress takes an intermediate position.

[The effect of the delta-sleep peptide on the adrenaline level in rat tissues under normal conditions and during cold stress]. / Vliianie peptida del'ta-sna na soderzhanie adrenalina v tkaniakh krys v norme i pri deistvii kholodnovogo stressa.

Adrenalin content in the brain, liver and adrenal glands under the effect of cold stress grows by 314, 500 and 56% as compared to the control. A single administration of the delta-sleep inducing peptide (DSIP) in a dose of 12 microgram/100 g to intact animals makes the adrenalin content in the brain higher 1, 3, 6 and 24h after administration; two and three days later the adrenalin content in the brain does not change. The amount of adrenalin in the liver of the same animals increases 1, 3, 6 h and 1, 2, 3 days after DSIP administration. Intraperitoneal administration of DSIP induces an increase of the adrenalin level in the adrenal glands of rats an hour and a day after administration. Two days later the level of adrenaline decreases by 41%; 3, 6 h and 3 days after DSIP administration the content of adrenaline remains unchanged. As a result of the DSIP administration in a dose of 12 micrograms/100 g to the animals in the state of cold stress, the content of adrenalin increases in the rat brain by 129, in the liver--by 300, adrenal glands--by 44% as compared with the control.

[Effect of the delta-sleep peptide on erythrocyte membrane function during low-temperature exposure]. / Vliianie peptida del'ta-sna na sostoianie membran éritrotsitov pri deistvii nizkoi temperatury.

3-day effect of low temperature increases the amount of extraerythrocyte hemoglobin by 64% in the blood serum, the activity of glucose-6-phosphatedehydrogenase increasing by 231%. Administration of 6.12 or 18 micrograms/100 g body weight of the delta-sleep peptide (DSIP) induces on change in amount of extraerythrocyte hemoglobin in the blood serum of intact rats. 6 micrograms/100 g DSIP increases the activity of glucose-6-phosphatedehydrogenase by 251.6%; 12 micrograms/100 g-- by 165.6%; 18 micrograms/100 g--by 90.6%. The normalizing effect on the level of extraerythrocyte hemoglobin and activity of glucose-6-phosphatedehydrogenase in low ambient temperature occurs at the dose of DSIP 12 micrograms/100 g body weight. The DSIP stabilizes the erythrocyte membranes in low temperature.

[Protective effect of arginine in hyperoxia. Activity of cerebral glutaminase and glutamate decarboxylase]. / Zashchitnoe deistvie arginina pri giperoksii. Aktivnost' glutaminazy i glutamatdekarboksilazy mozga.

Activity of glutaminase (both phosphate-dependent and phosphate-independent forms of the enzyme) as well as glutamate decarboxylase activity were studied in hyperoxia (6 ati) and under conditions of protection by means of arginine from the effect of hyperoxia. In hyperoxia activity of phosphate-dependent and phosphate-independent forms of glutaminase was decreased by 45% and 51%, respectively. At the same time, glutamate decarboxylase activity was decreased by 32%. Arginine showed a protective effect, delaying the time of oxygen convulsions onset by 2.5-fold. The low activities of glutaminases were maintained but the glutamate decarboxylase activity was increased and even exceeded the control level by 29%. A mechanism of the protective effect of arginine is discussed.

[Monoamine oxidase activity and gamma-aminobutyric acid levels in hyperoxia. The effect of clorgyline]. / Aktivnost' monoaminoksidazy i uroven' gamma-aminomaslianoi kisloty pri giperoksii. Vliianie khlorgilina.

Under conditions of hyperoxia mitochondrial monoamine oxidase (MAO) of the A type from rat brain proved to be able to deaminate gamma-aminobutyric acid (GABA); the transformation in the enzymatic properties appears to be responsible for a decrease in content of the intermediator in brain. Preadministration of chlorgiline (inhibitor of MAO of the A type) into animals before hyperoxygenation prevented completely the GABA content decrease, not affecting the glutamate decarboxylase activity, which was decreased in hyperoxia. At the same time, chlorgiline exhibited the total protective effect increasing 2-fold the period before oxygen convulsions.

[Evaluation of the effectiveness of the protective effect of arginine in cold stress]. / Otsenka éffektivnosti zashchitnogo deistviia arginina v usloviiakh kholodovogo stressa.

Cold exposition within 3 days at 2-4 degrees caused destabilization of rat erythrocyte membranes. Content of blood serum hemoglobin, total peroxidase activity and the glucose-6-phosphate dehydrogenase activity were increased. Resistance of the animals against high oxygen pressure was reduced. Administration of arginine within 3 days into the animals led to stabilization of membranes and to elevation of rat resistance towards high oxygen pressure.

[Homocarnosine levels in various regions of the rat brain and blood in hypoxia and after hyperbaric oxygenation]. / Soderzhanie gomokarnozina v otdelakh mozga i krovi krys v sostoianii gipoksii i posle deistviia giperbaricheskoi oksigenatsii.

Content of homocarnosine was studied in rat brain departments and blood after hypoxia (9,000 m, 60 min) and hyperoxia (0.3 mPa of oxygen, 60 min) following the hypoxia. In hypoxia content of homocarnosine was unaltered in brain hemispheres and medulla oblongata, it was increased by 41% in midbrain and cerebellum and by 80% in blood. Simultaneous effect of hypoxia and hyperbaric oxygenation decreased the homocarnosine content in brain hemispheres by 22%, in midbrain and diencephalon by 61%, in medulla oblongata by 34%, in cerebellum by 66% and in blood by 39%. Thus, therapeutic doses of hyperbaric oxygenation did not normalize the homocarnosine content in brain of animals with hypoxia.

[Protective effect of the neuropeptide homocarnosine in hyperbaric oxygenation]. / Protektornoe deistvie neiropeptida gomokarnozina pri giperbarooksigenatsii.

Homocarnosine, at a dose of 10 mg per 100 g of animal body mass administered intraperitoneally within 15 min before hyperbaric oxygenation with 0.7 MPa of oxygen, exhibited a protective effect. After administration of the neuropeptide into animals before hyperbaric oxygenation a latent period of oxygen convulsions was increased; content of homocarnosine and gamma-aminobutyric acid (GABA) was maintained at the level found in brain of control animals. In brain tissue of unprotected animals content of homocarnosine and GABA was decreased due to the oxygen treatment. GABA was less effective, its protective dose exceeded 10-fold the dose of homocarnosine. The neuropeptide exhibited antioxidant properties in reactions of lipid peroxidation under normal conditions and in hyperbaric oxygenation in vitro. The antioxidant activity of GABA was distinctly lower as compared with homocarnosine.

[Spontaneous deamidation of gamma-globulin]. / Spontanooe dezamidirovanie gamma-globulina.

gamma-Globulin from human blood serum was incubated in thermostat at 37 degrees within 15, 30, 45, 60 and 72 days. Amount of readily and poorly hydrolyzed amide groups as well as an increase in amino acid content were estimated in the protein at zero time and at these periods. The sterility of the preparation was examined in each case. Spontaneous deamidation of gamma-globulin, observed during incubation, caused an increase in negative charge and altered electrophoretic mobility of the protein molecule. gamma-Globulin was attacked by prothelin more effectively as amount of amide groups was decreased in the protein. Spontaneous deamidation appears to be one of reasons of the protein molecules ageing.