Effect of human defensins on the cytoplasmic Ca2+ content in platelets

The effect of the total fraction of human defensins (HNP-1, HNP-2, and HNP-3) on the cytoplasmic Ca²⁺ content ([Ca²⁺]_i) in the platelets of healthy donors was studied. At concentrations of 0.1–40 μg/ml and an incubation time of 10 min defensins have no effect on [Ca²⁺]_i in platelets labeled with Fura-2AM. However, at higher concentrations (100 μg/ml) they increased platelet [Ca²⁺]_i. In addition, defensins (40 μg/ml) inhibited the Ca²⁺ increase in platelets induced by thrombin, adenosine diphosphate, and the lipopolysaccharide ofS. typhimurium endotoxin. The most pronounced inhibitory effect was observed in a suspension of thrombin-stimulated platelets. It is shown that the effect of human defensins on the functional activity of platelets is due to the alterations in the intracellular Ca²⁺. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 12, pp. 600–603, December, 1994     

The development of free radical processes in experimental bronchospasm. Effect of the bronchodilator preparation troventol

The development of bronchospasm is shown to be accompanied by lipid peroxidation (LPO) activation; 3-fold and 8-fold rises of malondialdehyde concentration are found in homogenate of lung from sensitized animals and from animals provoked with egg albumin antigen, respectively. The use of luminol-dependent chemiluminescence (CL) reveals that in sensitized rats the production of oxygen free radicals is increased by alveolar macrophages activated with phorbol myristate acetate. Troventol at 10⁻³ mg/ml inhibits the CL response of phagocytes both in intact and in sensitized rats and lowers the level of Fe²⁺-induced LPO in lung tissue but not in the liver of intact animals. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 6, pp. 619–621, June, 1994     

Mechanism of heart-rate acceleration caused by stimulation of vagal centers in the frog

The mechanism by which heart rate is increased upon stimulation of vagal centers is studied using frog heart preparations perfused with Ringer—Locke solution containing atropine and/or benzohexonium. Atropine stimulates vagus-induced heart-rate acceleration in dilutions of 10⁻⁶ and 10⁻⁵ g/ml. In a dilution of 10⁻⁴ g/ml both atropine and benzohexonium abolish vagal tachycardia. Rausedyl (3–4 injections, 5 mg/kg, at 18–20-h interval) prevents tachycardia. Stimulation of both halves of the medulla oblongata increases heart rate to a greater extent than stimulation of one half. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 124, No. 7, pp. 16–20, July, 1997     

Effect of bromantane,a new immunostimulating agent with psychostimulating activity,on the release and metabolism of dopamine in the striatum of freely moving rats. A microdialysis study

It is demonstrated that bromantane induces a pronounced and prolonged (8 h) increase in the release of dopanime. Tetrodotoxin (10⁻⁶ M) perfused via a microdialysis probe partially inhibits the bromantane-induced release of dopamine. The extracellular content of the dopamine metabolites 3,4-dioxyphenylacetic and homovanillic acids is slightly decreased. The possible mechanisms of action of bromantane on the dopamin- and serotoninergic systems of the brain are discussed. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o . 3, pp. 302–304, March, 1995 Presented by M. D. Mashkovskii, Member of the Russian Academy of Medical Sciences     

Effect of ultralow doses of thyroliberin on microviscosity of lipid components of biological membranes

Effects of the regulatory peptide thyroliberin on microviscosity of lipid components of endoplasmic reticulum biological membranes in mouse hepatocytes were studied by electron paramagnetic resonance. Thyroliberin in a concentration of 10⁻³–10⁻¹⁸ M decreased microviscosity of surface layers of membrane lipids. This decrease was the most pronounced (30%) under effects of 10⁻¹⁰ and 10⁻¹⁶ M thyroliberin. Physiological effects of thyroliberin corresponded to its influence on the membrane structure. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 129, No. 1, pp. 38–40, January, 2000     

Inhibition of platelet aggregation by monoclonal antibodies against glycoprotein IIb–IIIa complex

Monoclonal antibodies CRC64 are obtained against Ca²⁺-dependent glycoprotein IIb–IIIa complex of the platelet membrane which possess the ability to inhibit completely fibrinogen-dependent platelet aggregation. CRC64 is directed against the epitope formed by the glycoprotein IIb–IIIa complex and does not interact with proteins isolated after platelets are treated with ethylenediamine tetraacetate. Complete, reproducible blockade of platelet aggregation caused by 5 μM adenosine diphosphate is noted in an MCA concentration of 3 μg/ml, while in the case of a stronger inductor, namely 1 U/ml thrombin, platelet aggregation is inhibited in a concentration of 5 μg/ml. F(ab′)₂ fragments are also able to inhibit platelet aggregation completely and are usually effective in concentrations lower than native monoclonal antibodies. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 10, pp. 402–405, October, 1994 Presented by V. N. Smirnov, Member of the Russian Academy of Medical Sciences     

Effects of the nootropics piracetam and GVS-111 on voltage-dependent ion channels of neuronal membranes

The effect of two nootropics, piracetam and N-phenylacetyl-L-prolyglycine ethyl ester (GVS-111), is studied by measuring high-threshold K⁺ and Ca²⁺ currents in isolated snail neurons using a two-microelectrode patch-clamp technique. Piracetam and GVS-111 are shown to reduce the amplitude of both the K⁺ and the Ca²⁺ (to a lesser extent) current. The threshold concentrations for GVS-111 and piracetam are 10⁻⁹-10⁻⁸ M and 1–5×10⁻⁴ M, respectively. It is assumed that the antiamnestic effect of the nootropics is partially mediated by a blockade of ion channels of the neuronal membrane. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 121, N ^o 2, pp. 151–155, February, 1996 Presented by G. N. Kryzhanovskii, Member of the Russian Academy of Medical Sciences     

Physiological concentrations of endothelin-1 cause only coronary vasodilatation in anesthetized rats

Various concentrations of the peptide endothelin-1 were tested for their effect on coronary vascular resistance in anesthetized rats. Intracoronary infusion of this peptide over 4 min in a total dose that gave rise to blood concentrations of 0.002–0.003 or 0.2–0.3 fmol/ml elicited only a decrease in the estimated coronary vascular resistance. It is suggested that only supraphysiological doses of endothelin are likely to exert a powerful vasoconstrictive effect on coronary vessels and cause myocardial ischemia. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 7, pp. 16–19, July, 1995 Presented by I. P. Ashmarin. Member of the Russian Academy of Medical Sciences     

Modulation of the oxidative burst in mouse macrophages and human neutrophils by superlow concentrations of GM1 ganglioside

It is shown that ganglioside GM1 in picomolar concentrations stimulates the phorbol-12-myristate-13-acetate (PMA)-induced generation of active forms of oxygen by neutrophils and peritoneal macrophages. GM1 (10⁻¹¹ M) is found to enhance the luminol-dependent chemiluminescence induced by 10⁻⁸ M PMA in mouse macrophages in comparison with the effect of PMA alone. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 1, pp. 44–46, January, 1994 Presented by A. N. Klimov, Member of the Russian Academy of Medical Sciences     

Effect of some lectins on the cholinergic structures of the frog heart

The effect of lectins (phytohemagglutinin — PHA, concanavalin A — ConA,Pisum sativum lectin — PSL,Ricinus communis lectin — RCL, and pokeweed mitogen — PWM) on the cardiac cholinoceptors is studied in experiments on isolated hearts of maleRana temporaria frogs. The test lectins in concentrations from 10⁻²³ to 10⁻³ are shown to exhibit cholinomimetic properties. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 9, pp. 252–255, September, 1994 Presented by A. D. Ado, Member of the Russian Academy of Medical Sciences     

Study of the hemostatic properties of gaseous ozone

The hemostatic properties of ozone were studied on models of parenchymatous (from a wound in the liver) and stem (from the stump of the tail) bleedings in rats. An air-ozone mixture at a flow rate of 1 liter/min and a concentration of 2 mg/ml was found to exert a pronounced hemostatic effect. Our findings indicate that the arrest of bleeding under the influence of ozone is due to the formation of a fibrin membrane on the surface of the flowing blood, this leading to rapid and effective hemostasis. Preliminary drying of the wound still further speeds the onset of hemostasis. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120 N ^o 7 pp. 62–65, July, 1995 Presented by D. S. Sarkisov, Member of the Russian Academy of Medical Sciences     

Effect of elementary proline-containing peptides on functional activity of anticoagulation system and primary homeostasis

Elementary proline-containing peptides being added to rat platelet-rich plasma or platelet suspension in concentrations of 10⁻¹–10⁻⁷ mg/ml elicit a considerable antiplatelet effect. Efficiency of inhibition of platelet aggregation increases in the following order: Pro-Gly>Pro-Gly-Pro>Gly-Pro-Gly-Gly. Intravenous injection of these peptides activates blood anticoagulation system in experimental animals. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 125, No. 4, pp. 496–499, May, 1998     

Synthesis and properties of the immunotoxin CD5-ricin

Synthesis and properties of an immunotoxin produced by conjugating ricin with a novel monoclonal antibody (IgG3 of the ICO-104 class) are described. Cytolytic activity of the synthesized immunotoxin, determined by two independent methods and expressed in LD₅₀, is 0.3–0.6×10⁻⁷ M. Its specificity for target cells containing the CD5 antigen is shown. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 1, pp. 76–79, January, 1995 (Presented by Yu. A. Romanov, Member of the Russian Academy of Medical Sciences)     

Impact of plasmin and its complexes with α2-macroglobulin or α2-antiplasmin on the proliferative activity of human lymphocyteson the proliferative activity of human lymphocytes

It is shown that plasmin in doses of 0.1, 1, or 10 μg/ml did not influence significantly phytohemagglutinin-induced proliferation of mononuclear lymphocytes in a 3-day culture with these cells. Their proliferative response to pokeweed mitogen was stimulated by plasmin in the dose of 10 μg/ml only. Biogenic complexes of plasmin with α₂-macroglobulin or α₂-antiplasmin induced a moderate reduction of spontaneous proliferation after 3 days of culture, and so did plasmin after 5 days; α₂-macroglobulin induced a dose-dependent comitogenic effect with phytohemagglutinin and pokeweed mitogen, while α₂-antiplasmin induced a dose-independent comitogenic effect with pokeweed mitogen. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 9, pp. 304–305, September, 1994 Presented by V. A. Trufakin, Member of the Russian Academy of Medical Sciences     

Ambiguity of the effect of high and low doses of amino-acid preparations on the immune response and phagocytosis in mice

It is shown that the effect of amino-acid preparations (levamine-70–70, cerebrolysin, and aviamine) is dose-dependent. Thus, levamine-70 and cerebrolysin at 65 mg/kg do not affect the immune response but stimulate phagocytosis. Aviamine at 65 mg/kg inhibits the immune response but stimulates phagocytosis and in a dose of 6.5×10⁻² mg/kg boosts both processes. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 5, pp. 500–501, May, 1994 Presented by A. D. Ado, Member of the Russian Academy of Medical Sciences     

Alterations in cardiac function in response to epinephrine in rats with hereditary hypertension (An ECG study)

A comparative electrocardiographic evaluation of changes in cardiac function in rats with hereditary arterial hypertension (NISAG strain) and normotensive (Wistar) rats in response to a single epinephrine injection revealed much more pronounced changes in NISAG rats, including an unfavorable time course of electrocardiographic waves (left ventricle overload) and impaired conduction (blockade) and excitability (extrasystoles). The results indicate that the myocardium of NISAG rats is much more responsive to the acute stimulation of adrenergic receptors by epinephrine than is the myocardium of normotensive rats. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 10, pp. 372–375, October, 1995 Presented by V. A. Trufakin, Member of the Russian Academy of Medical Sciences     

The state of the microcirculatory bed,microhemodynamics, and oxygen supply of the liver under conditions of disrupted parasympathetic innervation

Vagotomy is shown to result in disturbances of the microcirculation (a reduced rate of blood flow and distortion of its kinetics), the morphological basis of which consists of certain transformations of the microvascular network organization and ultrastructural changes in the cells lining the sinusoidal capillaries. The most pronounced disorders in microhemodynamics and blood supply of the liver are found 5–14 days after vagotomy. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 9, pp. 328–330, September, 1994 Presented by V. V. Kupriyanov, Member of the Russian Academy of Medical Sciences     

Effect of picrotoxin and bicuculline on desensitization of the GABA receptor/Cl− ionophore complex

A study is performed of the effect of the convulsants picrotoxin and bicuculline, blockers of GABA-dependent Cl⁻-conductivity, on the rate of desensitization of muscimol-induced³⁶Cl⁻ entry into synaptoneurosomes isolated from rat cortex. Both picrotoxin and bicuculline, despite the difference in the mechanisms of inhibition of the GABA receptor/Cl⁻ ionophore complex, markedly reduce the rate of desensitization. However, the initial moment of the action of both convulsants is characterized by inhibition of Cl⁻ transport alone, without a drop of the rate of desensitization. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 8, pp. 160–163, August, 1994     

The content of tocopherol and lipid peroxidation products in the tissues of rats with genetically determined hyperproduction of free oxygen radicals

It is shown that at the age of 2–3 months S rats with genetically determined hyperproduction of free radicals have the same content of tocopherol in the heart, epididymal fat, adrenals, liver, and liver mitochondria as Wistar rats but a lower content of plasma tocopherol. At 10–12 months, the tocopherol content in all studied tissues and organs, except the liver, is higher than in young S rats and age-matched Wistar rats. This is regarded as a compensatory response facilitating the stabilization of LPO under conditions of increased free radical formation. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 121, N ^o 3, pp. 282–284, March, 1996     

Nitric oxide synthase in bronchial epithelium and nitric oxide metabolites in the lungs of rats with bronchial asthma after fenoterol inhalation

Nitric oxide synthase of the bronchial epithelium and concentrations of nitric oxide metabolites (NO₂ ⁻ and NO₃ ⁻) in bronchoalveolar lavage fluids were measured in rats with bronchial asthma after fenoterol inhalation. It was suggested that nitric oxide-ergic mechanisms can mediate the effects of inhaled β₂-adrenergic agonists. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 130, No. 8, pp. 176–179, August, 2000