[Combined effect of adenosine and papaverine on the metabolism of adenine nucleotides in rat thymocytes]. / O sovmestnom deistvii adenozina i papaverina na metabolizm adeninnukleotidov v timotsitakh krysy.

It is shown that in [14C]adenine-labelled thymocytes adenosine increases the content of adenine nucleotides and simultaneously accelerates their catabolism. Papaverine induces acceleration of splitting and a decrease of the specific ATP radioactivity but increases the AMP content and its specific radioactivity. The both effectors intensify considerably the outlet of total radioactive label from cells. If the papaverine effect in the extracellular medium results in accumulation mainly of hypoxanthine in the extracellular medium then the adenosine presence causes accumulation of inosine and hypoxanthine approximately in equal amounts. The release of labelled adenosine from thymocytes in all cases is an insignificant part of extracellular radioactivity. A conclusion is drawn that under conditions of the combined action of the substances under study papaverine removes the adenosine effect caused by its under study papaverine removes the adenosine effect caused by its phosphorylation with the formation of ATP and exerts the dose-depended action on adenine nucleotide metabolism in thymocytes.

[The role of adenine nucleotide catabolism in the interphase death of thymocytes, caused by papaverine and dipyridamole]. / Rol' katabolizma adeninnukleotidov v interfaznoi gibeli timotsitov, vyzvannoi papaverinom i dipiridamolom.

Papaverine and dipyridamole induce the interphase death of thymocytes rapidly growing four hours later and reaching its maximum by the seventh-eighth hour of the cell incubation. To induce death of thymocytes no constant presence of these preparations in the incubation medium is needed, a definite (for each of preparations) time of the contact with cells being enough. The interphase death of thymocytes induced by papaverine and dipyridamole is preceded by acceleration of the release of adenine nucleotide catabolism products from cells mainly as hypoxanthine and inosine, respectively. These both processes are induced by papaverine for a shorter period of its incubation with cells than by dipyridamole and the joined use of these substances intensifies the above processes. The analysis of the data obtained indicates that thymocytes under the effect of papaverine die rather from the exhaustion of the adenine nucleotide pool, than from a decrease in the adenylate charge of cells. Exogenous adenosine essentially removes the toxic effect of papaverine but not of dipyridamole. Addition of adenine and inosine to thymocytes does not affect their survival rate in the presence of the preparations under study.

[Metabolism of adenosine, AMP and ATP in rats]. / Metabolizm adenozina, AMP i ATP u krys.

Metabolism of [14C]adenosine in a dose of 100 mg per 1 kg of mass and [14C]ATP in the equimolar quantity was studied in rats after intraperitoneal administration. Adenosine is shown to enter tissues of the liver, spleen, thymus, heart and erythrocytes where it phosphorylates into adenine nucleotides (mainly ATP) and deaminates into inosine. The content of adenosine increases for a short period in the above tissues, except for erythrocytes and plasma. The latter accumulates a considerable amount of inosine and hypoxanthine, but only traces of uric acid, xanthine and adenine nucleotides. ATP administered to rats catabolizes through the adenosine formation. The exogenic adenosine and ATP replace in tissues and erythrocytes only a slight part (1-12%) of their total adenine nucleotide pool. The content of these metabolites and ADP in the blood plasma does not change essentially under the effect of adenosine, ATP and AMP. It is shown on rats whose adenine nucleotide pool of cells is marked by the previous administration of [14C]adenine that injections of adenosine, ATP and inosine do not accelerate catabolism of adenine nucleotides in tissues and erythrocytes as well as do not increase the level of catabolism products in the blood plasma. Adenosine enhances and ATP lowers the content of cAMP in spleen and myocardium, respectively.

[Purification of biomolecules by the method of the expanded bed adsorption chromatography. III. Method optimization. Aplications].

This review introduces the principles of the expanded bed adsorption (EBA) and serves as a practical guide to the use STREAMLINE adsorbent and columns available on the market. Critical operational parameters will be discussed as well as the principles for the method design and optimization that will ensure maximum operation of this unique unit. The review is illustrated with the examples of different types of biological molecules which have been purified when using the expanded bed adsorption.

[Characteristics of adenosine activity on adenine nucleotide metabolism of rat thymocytes]. / Osobennost' deistviia adenozina na adeninnukleotidnyi metabolizm timotsitov krysy.

The effects of adenosine on adenine nucleotide metabolism in [14C]adenine-labeled rat thymocytes were studied. It was shown that adenosine increases the intracellular pool of adenine nucleotides, predominantly ATP, which is accompanied by marked acceleration of their catabolism and a release of labeled products (especially inosine, hypoxanthine and adenosine) from the thymocytes. The effect of adenosine depends on its concentration and manifests itself already at 10(-6) M. 2-Deoxycoformycin partly relieves the effect of adenosine on adenine nucleotide metabolism. Exogenous deoxyadenosine, inosine, hypoxanthine and adenine, unlike adenosine, do not significantly affect the adenine nucleotide catabolism and the label release from the cells. All the effectors under study strongly increase inosine transport from the thymocytes, and inhibit, with the exception of adenosine, the hypoxanthine release from the cells.

[Metabolism of adenine nucleotides in thymocyte cytoplasm and subcellular fractions after treatment with concanavalin A, papaverine and adenosine]. / Metabolizm adeninnukleotidov v tsitoplazme i subkletochnykh komponentakh timotsitov pri deistvii konkanavalina A, papaverina i adenozina.

Studies with rat thymocytes labeled with [14C]adenine and fractionated by digitonin treatment revealed that the cytoplasm of these cells contains about 60% of the total adenine nucleotide pool with a higher ATP/ADP ratio and metabolic activity as compared with the structural components. The incorporation of [14C]adenine and [14C]adenosine into thymocyte adenine nucleotides results in predominant labeling of cytoplasmic ATP, in which the specific radioactivity of this nucleoside triphosphate is two and three times as high as in subcellular structures. Concanavalin A decreases the ATP level in thymocytes without changing its specific radioactivity. This compound does not influence the total content and amount labeled adenine nucleotides in the structural fraction. Papaverine accelerates the catabolism of ATP, mainly in thymocyte cytoplasm and, in a lesser degree, in its structural fraction. In each fraction the papaverine-induced catabolism of ATP is localized in the compartment which is more intensively labeled with [14C]adenine than the whole fractionation ATP pool. Adenosine markedly accelerates adenine nucleotide catabolism in the cytoplasmic and structural fractions of thymocytes; however, only in the first one of them this acceleration is due to ATP elevation. Papaverine and adenosine do not directly influence either the content or specific radioactivity of adenine nucleotides of the structural fraction isolated from [14C]adenine-labeled thymocytes.

[Effect of dipyridamole and papaverine on adenosine absorption by the lymphocytes]. / Vliianie dipiridamola i papaverina na pogloshchenie adenozina limfotsitami.

It was shown that dipyridamole and papaverine induce concentration-dependent inhibition of the absorption of [14C] adenosine by thymocytes. This action is different in lymphocytes from different lymphoid organs and blood. Dipyridamole enhances the effect of various papaverine concentrations on the absorption of adenosine by thymocytes, but it does not exceed the maximal effect, achieved by the latter in high doses. It is supposed, that dipyridamole inhibits the cell transport of adenosine and papaverine influences the adenine-nucleotide metabolism.

[Adenylate cyclase from rat thymus and spleen lymphocytes]. / Izuchenie adenilattsiklazy limfotsitov timusa i selezenki krys.

It was found that adenylate cyclase from spleen lymphocytes is more active as compared to that from thymocytes, but is less sensitive to the activating effect of epinephrine and NaF. Adenylate cyclase from different subcellular fractions of thymocytes has different sensitivity to NaF. In the microsomal and mitochondrial fractions the enzyme is inhibited by NaF 7- and 2-fold, while in cell lysate and nuclear-cellular fractions it is activated 3- and 9-fold, respectively. In the presence of NaF adenosine, AMP, PPi and methylene diphosphonic acid inhibit the enzyme activity both in thymus and spleen lymphocytes. Creatine and CrP also significantly decrease the enzyme activity. NH4+ and concanavalin A have no effect and phytohemagglutinin stimulates the enzyme from both sources.

[Effect of adenosine, AMP and papaverine on the cAMP content in thymocytes prelabelled with 14C-adenine]. / Vliianie adenozina, AMF i papaverina na soderzhanie tsAMF v timotsitakh, predvaritel'no mechennykh 14C-adeninom.

A study was made of the effects of adenosine, AMP and papaverine on the content and specific radioactivity of cAMP and ATP in rat thymocytes prelabeled with 14C-adenine. It was established that each of the substances under study increases approximately 2-fold the intracellular cAMP content. Adenosine or AMP combined with papaverine raises the cAMP level more powerfully than it might be expected as a result of such an ordinary summation. Being cAMP precursors adenosine or AMP increase its level in thymocytes. However in the presence of papaverine they exercise their action via adenylate cyclase. Thymocytes demonstrate two ATP compartments prelabeled mainly with 14C-adenine relative to the general cellular ATP and are used for cAMP formation. The compartment with a greater specific radioactivity gives rise to cAMP in thymocytes incubated in the absence of effectors or upon addition of papaverine. The compartment having a lesser specific radioactivity serves as ATP source for adenosine or AMP-sensitive adenylate cyclase and rapidly catabolizes under the effect of papaverine.

[Effect of papaverine on the absorption and metabolism of 14C- adenosine and 14C-adenine in thymocytes]. / Vliianie papaverina na pogloshchenie i metabolizm [14C]adenozina i [14C]adenina v timotsitakh.

Some peculiarities of adenosine and adenine nucleotide metabolism in rat thymocytes were investigated. It was shown that the uptake of labelled adenosine or adenine by thymocytes is markedly inhibited by papaverine due to the decrease of the adenylate kinase activity, on the one hand, and to the acceleration of ATP catabolism and inosine and hypoxanthine release into the environment, on the other. ATP catabolism occurs in a special compartment which in [14C] adenosine and [14C] adenine prelabelled thymocytes has a higher specific radioactivity as compared with the whole cell. In [14C] adenine-prelabelled thymocytes and extracellular medium, papaverine does not influence the content but increases the specific radioactivity of adenosine.

[Purification of biomolecules by the method of adsorptional chromatography in the expanded bed. I. Principles of the method]. / Ochistka biomolekul metodom adsorbtsionnoi khromatografii v rasshirennom cloe. I. Printsipy metoda.

Principles the Expanded Bed Adsorption (EBA) have been described in the survey. The paper also deals with critical operation parameters, principles of the method design and optimization, which will guarantee maximum operation of this unique operation stage. All these problems have been discussed. The survey is illustrated by the examples of various types of biological molecules which have been purified using EBA.

[Biomoleculs purification by the method of the expanded bed adsorption chromatography. II. Design of the experiment]. / Ochistka biomolekul metodom adsorbtsionnoi khromatografii vo vzveshennom sloe. II. Proektirovanie éksperimenta.

This review introduces the principles of the Expanded Bed Adsorption (EBA) and serves as a practical guide to the use of STREAMLINE adsorbent and columns available on the market. Critical operating parameters will be discussed as well as principles for the method design and optimization which will ensure maximum exploitation of this unique operation stage. The review is illustrated with examples of different types of biological molecules which have been purified using Expanded Bed Adsorption.

[Effect of adenosine and adenine nucleotides on rat thymocyte blast transformation induced by concanavalin A]. / Izuchenie vliianiia adenozina i adeninnukleotidov na blasttransformatsiiu timotsitov krysy, vyzvannuiu konkanavalinom A.

Studies on the action of adenine nucleotides on the Con A-induced blast transformation of rat thymocytes have shown that addition of milimolar concentrations of AMP and ADP to the cultural medium as well as that of adenosine produce an inhibitory effect on the reaction. Addition to the cells of adenosine deaminase almost completely abolishes this effect. Unlike the nucleotides, the suppressant effect of ATP on thymocyte proliferation is less pronounced and is not reversed by addition of adenosine deaminase. cAMP and ATP given in the concentrations sufficient for giving rise to the protein kinase reaction and ammonium ions (1 mM) have no effect on thymocyte blast transformation. The latter is appreciably suppressed by 1 mM pyrophosphate and almost completely by papaverine and curantyl. The nucleotides added to the thymocytes get dephosphorylated, however, extracellular adenosine is not accumulated during 80 minutes, its concentration being of the order of 10(-6) M.