[The influence of ouabagenin on the growth and proliferation of cells in the organotypical culture].

The aim of the present work was to investigate the effect of ouabagenin on the growth and proliferation of cells in organotypic culture. The objects of study were explants of nerve, cardiac, retina and liver tissue of 10-12 day old chicken embryos. Inhibitor of Na+,K(+)-ATPase ouabagenin was investigated in a wide range of concentrations (0.1 nM-1 mM). It has been found that the ouabagenin controls cell growth and proliferation in a dose-dependent manner and tissue-unspecific. The data obtained show that ouabagenin regulates only the pumping function of Na+,K(+)-ATPase.

[Role of oubain in regulation of growth of different tissues].

Using the method of organotypical cell culture, experimental data was obtained supporting the hypothesis that chelate complex ouabain-Ca2+ modulates the transducer function of Na+, K+- ATPase. Quantum-chemical calculations helped to elucidate two principally distinct modes for chelation of Ca2+ ions by ouabain molecule. It is predicted that ligang-receptor complex of ouabain-Ca2+--Na+,K+-ATPase is formed due to ion-ionic bonds. The forming of this complex switches on the transducer function of the sodium pump. Our data also show that removal of free Ca2+ ions from the cell culture media using EGTA has no effect on binding of ouabain with pumping control site of Na+K+-ATPase.

[Effect of Na(+), K(+)-pump inhibitors on the sensory ganglia neurite growth].

Inhibitors of Na(+), K(+)-pump belonging to the class of cardiac glycosides were investigated in organotypic tissue culture of dorsal root ganglia cells of 10-12 days old chicken embryos. The data obtained show that the application of cardiac glycosides (strophantin K and digoxin) in a wide range of concentrations controls the neurite growth in sensory neurons in the dose-dependent manner. It was shown, that at the concentrations of cardiac glycoside exceeding 1 x 10(-6) M the growth of neurites was totally inhibited. Our data indicate that cardiac glycoside have the down-regulation effect on the neurite growth. The data obtained indicate that the Na(+), K(+)-ATPase is involved in the control of the process of neurite growth as a signal transducer.

[Comparative analysis of the cardiac glycosides action on the growth of the cardiac tissue explants].

The method of organotypical cell culture was used. The long-term cell culture of cardiac embryonic tissue of 10-12-days old chicken was investigated. The effects of ouabaine, strophantin K and digoxin on the growth of cardiac tissue explant were measured. The ouabain concentration which stimulates activity of Na+, K+-ATPase as the signal transducer, was determined. It was equal to 10(-10) M. Strophantin K and digoxin stimulate growth of cardiac tissue in concentration equal to 10(-16) M and 10(-18) M, resp. The data obtained show that application of cardiac glycosides led to control of cardiac tissue growth in dose-dependent manner. We hypothesize that alpha3 isoform of Na+, K+-ATPase is a signal transducer that controls the cardiac cell metabolism and growth.

[The modulating action of amino acids upon development in an organotypic culture]. / Moduliruiushchee deistvie aminokislot na razvitie tkanei v organotipicheskoi kul'ture.

The effect of L-amino acids in concentration 0.05 ng/ml was investigated in organotypic tissue culture of spleen, liver and brain cortex at the age of 1 and 21 days. The high molecular and low hydrophobic amino acids: asparagin, lysine, arginine, and glutamine, are active inducing both a less intensive growth zone in explants of all three tissue types in 1-day old rats and more intensive growth zone in spleen, liver explants in 21-day rats as compared to control. Another group of low molecular and high hydrophobic amino acids is active inducing a more intensive growth zone in brain cortex explant in 21-day rats, as compared to control. The data obtained suggest a modulating role of amino acids in the tissues at different stages of maturation.

[The modulating role of essential and non-essential amino acids in organotypic tissue culture in rats of different ages]. / Moduliruiushchaia rol' nezamenimykh i zamenimykh aminokislot v organotipicheskoi kul'ture tkanei u krys raznogo vozrasta.

The effect of amino acids L-lysin, L-asparagin, L-arginin, L-glutamate was investigated in organotypic tissue culture of spleen, liver and brain cortex of rats at different age. The amino acids in concentration 0.05 ng/ml are active inducing a less intensive growth zone, as compared to control, in 1-day and in older rats--an intensive growth zone, as compared to control in 21-day rats. The data obtained suggest a modulating role of amino acids in the tissues at different stages of maturation.

[Characteristics of endoribonuclease activity of proteasomes from K562 cells. I. Dependence of RNAase activity of proteasome and alph-RNP on conditions of endonucleolysis reaction]. / Kharacteristiki éndoribonukleaznoi aktivnosti proteasom iz kletok linii K562. I. Zavisimost' RNKaznoi aktivnosti proteasom i alpha-RNP ot uslovii reaktsii éndonukleoliza.

Proteosomes from human proerythroleukaemic cell line K562 are found to degrade high molecular weight cytoplasmic RNAs, particularly ribosomal and specific messenger RNA. This activity was observed to be endoribonucleotylic. The induction of differentiation by erythroid pathway in K562 cells invokes augmentation of endonuclease activity in proteasomes. The number of characteristics of this enzymatic activity was investigated. Specificity of endonuclease of these RNPs is shown to be Ca- and Mg-dependent. Dephosphorylation of protein subunits suppresses RNase activity of proteasomes. Endonuclease of proteasomes is thermolabile. The examined activity depends on the secondary structure of substrate RNA. Protein subunits are responsible for ribonuclease activity of proteasomes rather than for low molecular weight RNAs associated with the complex.

[Novel endoribonuclease activity of 26S-proteasomes from A-431 cells]. / Novaia éndoribonukleaznaia aktivnost' 26S-proteasom iz kletok linii A-431.

Our analysis detected in 26S proteasomes of human A-431 cells a strong endoribonuclease activity, degrading cytoplasmic high-molecular-mass RNA, particularly, specific mRNAs. Enzymatic nature of this activity has been confirmed, and the optimal conditions studied. This endonuclease activity of proteasomes has not been earlier observed. Proteasome involvement in the stability control of specific messenger RNA molecules is suggested, and proteasome participation in the coordinated control of various stages of gene expression is discussed.

[Effect of cytomedins on development of organotypic culture of various tissues from the internal organs of rats]. / Vliianie tsitomedinov na razvitie organotipicheskoi kul'tury razlichnykh tkanei vnutrennikh organov krysy.

Some natural peptides, referred to as cytomedines, were isolated from different organs: cortexin and epithalamin (both from the brain), cordialin (heart), hepalin (liver) and thymalin (thymus),--to test their stimulating effects on the growth in organotypic culture of different tissue explants taken from 3 day old rats. It has been found that these peptides exerted their obvious stimulating effects on the growth of the cultured explants, compared to the control, if taken in the respective concentrations: 100, 50, 50, 100 and 5 ng/ml. Thus, these cytomedins can be used in the clinical practice for stimulating reparative processes in the appropriate tissues.

[Effect of thymus polypeptide fractions on the development of rat thymus and spleen in organ culture]. / Vliianie polipeptidnykh fraktsii timusa na razvitie organotipicheskoikul'tury vilochkovoi zhelezy i selezenki krysy.

Peptides of the thymus--vilon, thymogen and thymalin, alone or in combination with concanavalin A, were used to investigate their effect on organotypic culture of thymus and spleen explants from 1- and 21-day old rats. Vilon, thymogen and thymalin in concentrations of 2 and 10 ng/ml and 5 ng/ml, resp., exerted stimulating effects in thymus and spleen tissue cultures from 21-day old rats as compared to the control explants. Vilon and thymogen showed inhibiting effect in the thymus tissue cultures from 1-day old rats as compared to the control explants. However, the peptides together with concanavalin A in concentration of 10 mkg/ml resulted in decreasing the action of concanavalin A alone. The polypeptide fractions of thymus and their synthetic analogs play different roles in the regulation of thymus and spleen development in rats of different age.

[The stimulating effect of destabilase, a component of Hirudo medicinalis salivary gland secretion, on sensory neuron neurite growth in organotypic culture]. / Stimuliruiushchee vliianie destabilazy, komponenta sekreta, sliunnykh zhelez meditsinskoi piiavki, na rost neiritov chuvstvitel'nykh neironov v organotipicheskoi kul'ture.

The effect of destabilase, a component of Hirudo medicinalis salivary gland secret, was investigated in organotypic tissue culture of dorsal root ganglia (DRG) of 10-11-day old chick embryos. Native destabilase in concentrations 0.01 and 0.05 ng/ml was active, inducing a more intensive neurite growth in DRG that in the control. The stabilizing activity of destabilase was lost following reverse-phase chromatography. Neurite-stimulating effects of the drug "pyjavit" is due presumably to neurite-stimulating activity of destabilase.

[The protective effect of the nerve growth factor in exposing a nerve tissue culture to diphtheria toxin]. / Protektivnyi éffekt faktora rosta nervov pri vozdeistvii difteriinogo toksina na kul'turu nervnoi tkani.

Diphtheria toxin (1.10(-1)-1.10(-6) Lf/ml) was found to inhibit neurite extension in chick embryo dorsal root ganglia in vitro. If the nerve growth factor (60 ng/ml) was added with toxin in culture media the diphtheria toxin effect was decreased and the neurite outgrowth was compared with control. Protective effect of nerve growth factor by influence of diphtheria toxin may be used in new principles of diphtheria treatment.

[The effect of activated macrophage products on neurite growth in an organotypic culture of chick embryo sensory ganglia]. / Vliianie produktov aktivirovannykh makrofagov na rost neiritov v organotipicheskoi kul'ture chuvstvitel'nykh gangliev kurinykh émbrionov.

Murine peritoneal macrophages, activated by BCG vaccine, and human peripheral blood monocytes, activated by lipopolysaccharides, exerted neurite stimulating or neurite inhibiting effects in various periods of activation. The supernatants of these preparations were active in organotypic culture of chick embryo dorsal root ganglia. The inhibition of neurite growth on the 1st day of cultivation was followed by the neurite-stimulating effect. The fluctuation of neurite-inhibition and neurite-stimulation effect of macrophage supernatants suggest the availability of certain changes in cytokine composition in different periods of macrophage activation.