[Synergism of carbamylated darbepoetin and L-ethoxidol in the model of experimental kidney ischemia].

AIM: to determine the efficiency of different doses of erythropoietin and carbamylated darbepoetin, to prove experimentally the possibility of increasing the efficiency of carbamylated darbepoetin when using the levorotatory stereoisomer of ethoxidol. MATERIALS AND METHODS: On the model of ischemia-reperfusion injury in male CD-1 mice that were undergone to contralateral nephrectomy, the nephroprotective effect of different doses of erythropoietin alfa, carbamylated darbepoetin, L-ethoxidol (the levorotatory enantiomer of ethylmethylhydroxypyridine malate), and the combined use of L-ethapylated carboxypyridine malate and L-etapoietin alfa was studied. The parameters of microcirculation and glomerular filtration rate were studied one day after 30-minute ischemia. RESULTS: It has been established that the prophylactic use of erythropoietin alfa and carbamylated darbepoetin in the model of ischemia-reperfusion injury of a single kidney reduces the severity of microcirculatory impairment and ensures the preservation of the glomerular filtration rate in dose-dependent manner. The synergistic effect of L-ethoxidol and carbamylated darbepoetin was found when these substances were used together. CONCLUSION: Prevention of ischemia-reperfusion kidney injury by analogs of human erythropoietin and their combination with ethylmethylhydroxypyridine derivatives is experimentally-proved.

[Antiarrhythmic properties of 2-(2'-hydroxy-2')-substituted ethyl-1,2,3,4-octahydropyrrolo[1,2-a]pyrazines]. / Antiaritmicheskie svoistva 2-(2'-gidroksi-2'-zameshchennykh)-étil-oktagidropirrolo[1,2-a]pirazinov.

The antiarrhythmic activity and acute toxicity of a series of 2-(2'-hydroxy-2')-substituted ethyloctahydropyrrolo[1,2-a]pyrazines were studied. Two most promising compound (PV-238) is characterized by high antiarrhythmic activity, broad spectrum of action, and low toxicity.

[2-(2'-hydroxy 2'-substituted) ethyl-1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazines--a novel group of substances with anti-arrhythmia activity]. / 2-(2'-Gidroksi-2'-zameshchennye) étil-1,2,3,4-tetragidropirrolo[1,2-a]piraziny--novaia gruppa veshchestv, obladaiushchikh antiaritmicheskoi aktivnost'iu.

The antiarrhythmic activity and acute toxicity of a series of 2-(2'-hydroxy-2'-substituted) ethyl-1,2,3,4-tetrahydropyrrolo[1,2- a]pyrazines were studied. Two most promising compounds (PV-168 PV-174) are characterized by a high antiarrhythmic activity, a broad spectrum of action, and low toxicity.

Cytotoxic effects of dynorphins through nonopioid intracellular mechanisms.

Dynorphin A, a prodynorphin-derived peptide, is able to induce neurological dysfunction and neuronal death. To study dynorphin cytotoxicity in vitro, prodynorphin-derived peptides were added into the culture medium of nonneuronal and neuronal cells or delivered into these cells by lipofection or electroporation. Cells were unaffected by extracellular exposure when peptides were added to the medium. In contrast, the number of viable cells was significantly reduced when dynorphin A or "big dynorphin," consisting of dynorphins A and B, was transfected into cells. Big dynorphin was more potent than dynorphin A, whereas dynorphin B; dynorphin B-29; [Arg(11,13)]-dynorphin A(-13)-Gly-NH-(CH(2))(5)-NH(2), a selective kappa-opioid receptor agonist; and poly-l-lysine, a basic peptide more positively charged than big dynorphin, failed to affect cell viability. The opioid antagonist naloxone did not prevent big dynorphin cytotoxicity. Thus, the toxic effects were structure selective but not mediated through opioid receptors. When big dynorphin was delivered into cells by lipofection, it became localized predominantly in the cytoplasm and not in the nuclei. Big dynorphin appeared to induce toxicity through an apoptotic mechanism that may involve synergistic interactions with the p53 tumor-suppressor protein. It is proposed that big dynorphin induces cell death by virtue of its net positive charge and clusters of basic amino acids that mimic (and thereby perhaps interfere with) basic domains involved in protein-protein interactions. These effects may be relevant for a pathophysiological role of dynorphins in the brain and spinal cord and for control of death of tumor cells, which express prodynorphin at high levels.

Clustering of apoptotic cells via bystander killing by peroxides.

Clustering of apoptotic cells is a characteristic of many developing or renewing systems, suggesting that apoptotic cells kill bystanders. Bystander killing can be triggered experimentally by inducing apoptosis in single cells and may be based on the exchange of as yet unidentified chemical cell death signals between nearby cells without the need for cell-to-cell communication via gap junctions. Here we demonstrate that apoptotic cell clusters occurred spontaneously, after serum deprivation or p53 transfection in cell monolayers in vitro. Clustering was apparently induced through bystander killing by primary apoptotic cells. Catalase, a peroxide scavenger, suppressed bystander killing, suggesting that hydrogen peroxide generated by apoptotic cells is the death signal. Although p53 expression increased the number of apoptoses, clustering was found to be similar around apoptotic cells whether or not p53 was expressed, indicating that there is no specific p53 contribution to bystander killing. Bystander killing through peroxides emitted by apoptotic cells may propagate tissue injury in different pathological situations and be relevant in chemo-, gamma-ray, and gene therapy of cancer.

[Localization of disulfide bonds in the alpha 1 acidic glycoprotein molecule and study of their effect on ability of the protein to interact with ethidium bromide]. / Lokalization disul'fidnykh sviazei v molekule kislogo glikoproteina alpha1 i issledovanie ikh vliianiia na sposobnost' belka vzaimodeistvovat' s bromistym étidiem.

alpha 1-Acid glycoprotein (orosomucoid) was purified from the human and murine blood sera using phenol deproteinization. As opposed to the murine protein, the human orosomucoid bound the fluorescent dye ethidium bromide but lost this ability after treatment with beta-mercaptoethanol, which breaks disulfide bonds. Disulfide bonds between the Cys23 and Cys165 residues of the human orosomucoid and between the Cys91 and Cys184 residues of the murine orosomucoid were identified.

Opioids modulate cell division in the germinal zone of the late embryonic neocortex.

Opioid effects on cell division in the embryonic cerebral cortex were examined using two experimental approaches: (i) the presence of opioid receptors in the embryonic day 16 mouse neocortex was tested using immunohistochemical techniques; (ii) the values of the indices of [3H]thymidine pulse labelled cells and mitotic indices were estimated in the ventricular zone of the embryonic day 16 mouse neocortex 2.5, 4.5 and 8.5 h after administration to pregnant females of selected opioid receptor agonists or the opioid antagonist naloxone. The immunohistochemical study demonstrated that distinct subpopulations of the ventricular zone cells express mu, delta or kappa opioid receptors. Acute exposure of mouse embryos to mu, delta and kappa opioid receptor agonists or naloxone differentially affects the indices of [3H] thymidine pulse labelled cells and mitotic indices indicating changes in the cell cycle composition. Treatment with the mu opioid receptor agonist D-Ala2-MePhe4, Gly-ol5-enkephalin (DAGO), or the partially selective kappa opioid receptor agonist bremazocine, increased the [3H]thymidine labelling and mitotic indices. In contrast, the delta receptor agonist (D-Ser8)-leucine enkephalin-Thr (DSLET) produced a decrease in the labelled cell indices and mitotic indices. Naloxone provided a biphasic effect: a decrease in the values of labelled cell indices 2.5 h after naloxone administration, followed by an increase in the values of the indices at 4.5 and 8.5 h. These results suggest that the endogenous embryonic/maternal opioid systems are involved in the regulation of cell division in the ventricular zone of the late embryonic cortex.

[Use of thymogen in the treatment of various forms of acute abdominal disorders in an experiment]. / Primenenie timogena v lechenii nekotorykh vidov ostroi abdominal'noi patologii v éksperimente.

The authors have carried out experimental studies of thymogen action on the course of acute pancreatitis and acute peritonitis in white albino rat males. The preparation was introduced into the abdominal cavity early after the modeling and every 24 hours for 5 days. The results of the trial demonstrate that the degree of autoenzyme aggression (the data of blood serum alpha-amylolytic activity control) and the content of lipid peroxidation products (assessment of malonic dialdehyde quantity in tissue homogenate) were low in the experimental group as compared to the untreated animals. In the experimental group less pronounced depression of antiradical activity (superoxide dismutase and catalase activity control) was found, leukocytosis and leukocyte intoxication index were diminished. Thus, the efficiency of thymogen in acute inflammatory and destructive abdominal diseases has been proved.

Clonal heterogeneity in the early embryonic rodent cortical germinal zone and the separation of subventricular from ventricular zone lineages.

The cell cycle kinetics of individual clones of cells in the embryonic cortex were studied to determine the amount of heterogeneity among cortical progenitors. This kinetic heterogeneity may be the first sign of heterogeneous differentiation in the proliferating cortical germinal zone. Retroviral lineage tracing of clonal progeny in the embryonic day 16 (E16) rat cortex (48 hr after the retroviral infection and [3H]thymidine labeling of proliferating cells) permitted a description of the formation of the preplate in the medial cortex and the formation of the subventricular zone (SVZ) in the lateral cortex. Forty percent of the retrovirally tagged clones were double-labeled with a pulse of [3H]thymidine, corresponding to the 40% of ventricular zone cells in S-phase at the time of [3H]thymidine injection. Most of clones had cell numbers with powers of 2 (2, 4, and 8 cells), suggesting synchronous modes of division. Nevertheless, 15% of the retrovirally tagged clones that were double-labeled with [3H]thymidine at the time of [3H]thymidine injection showed asynchronous mode of division. Clonally related cells in the ventricular zone showed considerable variability in cell cycle times: 56% of the clones (8-cell clones) were composed of faster cycling cells with cell cycle times of 12 hr, and 25% of the clones (4-cell clones) represented slower cycling cells with cell cycle times of 16 hr. The clones migrating outside the ventricular zone differed in size and spatial distribution in the lateral versus medial cortex. In the lateral cortex, half the migrating clones were large proliferating 8-cell clones with all their members contained within the forming SVZ. In the medial cortex, the majority of the migrating clones were 2-cell and 4-cell clones. Given that the medial cortex matures later than the lateral neocortex and that no SVZ has formed in the rat medial cortex by E16, we suggest that the majority of cells that leave the medial cortical VZ by E16 are cells destined to form the neuronal populations of the preplate. The early embryonic cortical ventricular zone includes a mosaic of specialized progenitor cells.

[The effect of thymogen on the heart in ischemia and reperfusion]. / Vliianie timogena na sostoianie serdtsa pri ishemii i reperfuzii.

The anti-ischemic properties of thymogen were studied on an isolated heart model. Its cardioprotective effect was higher than that of dalargin and verapamil. The mechanism of the thymogen anti-ischemic action is realized without the participation of the opiate receptors and blockade of calcium entrance into the cardiomyocytes.

Variability and partial synchrony of the cell cycle in the germinal zone of the early embryonic cerebral cortex.

Cell cycle parameters were estimated using the cumulative 3H-thymidine S-phase labeling and percentage of labeled mitoses methods in the embryonic day 14 and 15 germinal zone of the rat cerebral cortex. The shortest cell cycle time was seen in the dorsal neocortex and the longest in the lateral neocortex and fimbria (the latter also had a low growth fraction). No differences were observed in cell cycle times between the cells in the ventricular and subventricular zone in the same neocortical region. The results suggest gradients of lengthening cell cycle times extending ventrolaterally and ventromedially from the dorsomedial neocortex. Although a majority of proliferating cells in individual cortical regions seem to belong to one population in terms of cell kinetics, several pieces of evidence suggest some heterogeneity: the asymmetric shapes of the percentages of labeled mitoses curves, the small population of noncycling neuroepithelial cells in the neocortex and mesocortex, and small population of cells that become pyknotic. Groups of DNA-synthesizing nuclei that were ectopically located in the inner half of the ventricular zone also indicate the existence of different subpopulations of neuroepithelial cells. In addition, after a pulse injection of 3H-thymidine the germinal zone is characterized by alternating clusters of heavily and lightly labeled cell nuclei that may reflect the simultaneous passage of a cluster of cells through the same portion of S-phase. We suggest that partial cell cycle synchrony within groups of ventricular cells may explain the presence of these iterative cell kinetic patterns in the developing cortex.

[A new two-stage plan for isolating human alpha1-acidic glycoprotein (orosomucoid). Orosomucoid interacts with ethidium bromide]. / Novaia dvukhstadiinaia skhema vydeleniia chelovecheskogo alpha1- kislogo glikoproteina (orozomukoida). Orozomukoid vzaimodeistvuet s bromistym étidiem.

Human alpha 1-acid glycoprotein (orosomucoid, AGP) was purified to homogeneity by a two-step procedure using phenol and chloroform deproteinization of serum with subsequent preparative electrophoresis on agarose gel. It was obtained 0.15-0.3 mg of protein from 1 ml of serum. Human alpha 1-AGP binds ethidium bromide but not DNA. Neither other human serum proteins nor mice and rat alpha 1-AGP bind ethidium bromide. This property of human orosomucoid depends on its amino acid sequence rather than on the carbohydrate part of the molecule.

[The anti-arrhythmia properties of thymogen]. / Antiaritmicheskie svoistva timogena.

The antiarrhythmic and antifibrillary effects of thymogen were determined by using 6 models of arrhythmias induced by aconitine, calcium chloride, strophanthin, low-sodium, reperfusion, and epinephrine. The dose-response curve was examined. The mechanism of thymogen's action was also studied.

[The effect of a number of pharmacological preparations on Na-H metabolic activity and on the passive permeability for protons of the sarcolemma of the isolated heart]. / Vliianie riada farmakologicheskikh preparatov na aktivnost' Na--H-obmena i passivnuiu pronitsaemost' sarkolemmy izolirobvannogo serdtsa dlia protonov.

The influence of the local anesthetics hydrocortisone hemisuccinate and peptide drugs (thymogen and dalargin) on Na-H exchange activity and passive proton permeability of the sarcolemma was studied in experiments on isolated rat hearts. It was established that neither local anesthetics or hydrocortisone hemisuccinate, nor peptide drugs affected Na-H exchange activity. Lidocaine (5 mM), procaine (5 mM), hydrocortisone hemisuccinate (500-750 mg/l) inhibited sarcolemmal passive proton permeability by 40-70%. Aetaphone in the micromolar range attenuated the role of these effects in the antiarrhythmic action of local anesthetics and aetaphone.

[The effect of dalargin on the course of experimental cardiac arrhythmias]. / Vliianie dalargina na techenie éksperimental'nykh aritmii serdtsa.

Five models of arrhythmias (aconitine-, calcium chloride- and low-sodium-induced models on rats, coronary artery ligation and reperfusion in dogs) were used to study the antiarrhythmic and antifibrillatory effects. The latters were not inferior to those shown by the well-known antiarrhythmics. The mechanisms of the action of dalargin are discussed in the paper.

[DNA hyperproduction in the blood plasma of animals with experimental diabetes and its compensation using the transplantation of insulin-producing tissue into the anterior chamber]. / Giperproduktsiia DNK v plazme krovi u zhivotnykh s éksperimental'nym diabetom i ee kompensatsiia s pomoshch'iu transplantatsii insulinprodutsiruiushchei tkani v peredniuiu kameru glaza.

Comparative analysis of serum DNA content in healthy rats, rats with experimental alloxan diabetes, and the rats with the diabetes compensated by transplantation of the embryonal pancreas into the anterior chamber of the eye. In the course of diabetes the concentration of free-circulating serum DNA reliably increase 10-12 times, and the compensation of the diabetes returns it to the norm. The revealed relationship may be used for diagnostics of initiation and full compensation of the insulin-dependent diabetes.