A study of the mechanism of action of befol on Ca2+ metabolism in cardiomyocytes using a FURA-2 fluorescent probe

The dynamics of the Ca-response of cardiomyocytes is studied and the efficiency of befol, verapamil, and amiodarone is compared using various experimental models of stimulation of [Ca²⁺]_i. Befol (1–5 μM) is shown to inhibit the caffeine-and strophanthin G-induced rise of [Ca²⁺]_i. Unlike verapamil and amiodarone, befol exhibits no Ca-blocking activity in modeled K-depolarization. It is concluded that the cardiotropic effect of befol is mediated through its primary action on Na⁺/Ca²⁺ exchange in cardiomyocytes, while the cardioplegic effect of verapamil and amiodarone is due to their ability to block the slow Ca²⁺ inward current. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 121, N ^o 3, pp. 288–291, March, 1996     

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     

Cascade afteraction of delta sleep-inducing peptide in rats

Delta sleep-inducing peptide is found to alter markedly the levels of substance P, β-endorphin, and corticosterone in the hypothalamus and blood plasma of rats, suggesting that the long-lasting stress-mitigating effects of this peptide are due to the considerable changes it causes in the content of other oligopeptides and hormones, involving them in various processes. Thus, DSIP itself appears to act only as a trigger, initiating a cascade of interdependent molecular reactions that correlate with the degree of resistance to stress. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 1, pp. 6–9, January, 1995     

Effect of polycation based on alkaloid lupinin-antihepolin and its complex with heparin on DNA synthesis in rat hepatocytes

The effect of the antiheparinate antihepolin on the intensity of replication processes in rat hepatocytes was studied. A single intravenous infusion of polycation caused an approximately 6-fold increase in the intensity DNA synthesis on day 2 postinjection followed by a drop to thebaseline level on days 5–6. If antihepolin was injected in parallel with heparin, DNA synthesis was intensified after just 24 hours. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 6, pp. 627–629, June, 1994 Presented by B. T. Velichkovskii, Member of the Russian Academy of Medical Sciences     

Glucocorticoid-dependent regulation of the expression of high-density lipoprotein binding sites in rat hepatocytes

It is shown that dexamethasone increases the number of HDL binding sites in cultured hepatocytes bothin vivo andin vitro. The glucocorticoid acts in a dose-dependent and reversible manner within a wide range of concentrations, including physiological and subphysiological doses. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 1, pp. 47–50, January, 1994     

Potentiation and acceleration effects in combined administration of tissue plasminogen activator and fibrinogen-modified urokinase in dogs with modeled venous thrombosis

Combined administration of tissue plasminogen activator and a urokinase-fibrinogen covalent conjugate is studied using modeled venous thrombosis in dogs. In comparison with the effect of the individual preparations the thrombolytic effect was potentiated when intravenous bolus injection of 1 mg tissue plasminogen activator followed by a 2-hour infusion of 4 mg of this preparation was combined with bolus injection of 25,000 IU urokinase-fibrinogen covalent conjugate 15 min after the first bolus. Potentiation and acceleration of thrombolysis were attained with the same scheme when tissue plasminogen activator was administered in a dose of 1 mg for both bolus and infusion and combined with 250,000 IU of fibrinogen-modified urokinase. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 121, N ^o 1, pp. 48–51, January, 1996 Presented by E. I. Chazov, Member of the Russian Academy of Medical Sciences and Russian Academy of Sciences     

Propagation of the [<Emphasis Type="Italic">PIN</Emphasis><Superscript><Emphasis Type="Italic">+</Emphasis></Superscript>] prion by fragments of Rnq1 fused to GFP

Prions are viewed as enigmatic infectious entities whose genetic properties are enciphered solely in an array of self-propagating protein aggregate conformations. Rnq1, a yeast protein with yet unknown function, forms a prion named [PIN ⁺ ] for its ability to facilitate the de novo induction of another prion, [PSI ⁺ ]. Here we investigate a set of RNQ1 truncations that were designed to cover major Rnq1 sequence elements similar to those important for the propagation of other yeast prions: a region rich in asparagines and glutamines and several types of oligopeptide repeats. Proteins encoded by these RNQ1 truncations were tested for their ability to (a) join (decorate) pre-existing [PIN ⁺ ] aggregates made of wild-type Rnq1 and (b) maintain the heritable aggregated state in the absence of wild-type RNQ1. While the possible involvement of particular sequence elements in the propagation of [PIN ⁺ ] is discussed, the major result is that the efficiency of transmission of [PIN ⁺ ] from wild-type Rnq1 to a fragment decreased with the fragment’s length. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Effect of the tetrapeptide tuftsin on the bioelectrical activity of brain structures in cats with different functional states of the central nervous system

The tetrapeptide tuftsin (Thr-Lys-Pro-Arg) injected intraperitoneally into cats altered the bioelectrical activity of sensory, motor, and limbicoreticular structures in the wakeful state, during two different phases of sleep, and also when the caudate nucleus was electrically stimulated. In wakefulness and during REM sleep, absolute values of the electroencephalographic power spectrum were increased in all the brain structures under study, while during slow-wave sleep they were increased in the sensorimotor cortical areas and decreased in the central medial thalamic nuclei and hippocampus. Tuftsin facilitated the genesis of slow waves in subcortical structures and the expression of theta waves in the hippocampus. It also increased the amplitude of evoked potentials and elongated spindles when the caudate nucleus was stimulated. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, vol. 119, N ^o 4, pp. 365–368, April, 1995     

Stereological ultrastructural analysis of rat cardiomyocytes after total hyperthermia

Hyperthermia results in the suppression of intracellular regeneration in cardiomyocytes, manifested as intensified lysis and destruction of organelles, and leads to myocardial atrophy. Intracellular reorganization of cardiomyocytes is characterized by increases in the volume and surface density of myofibrils, sarcoplasmic reticulum, and T system. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 1, pp. 96–100, January, 1994 Presented by V. A. Trufakin, Member of the Russian Academy of Medical Sciences     

The effect of nerve growth factor on a selective increase in the cell body size of rat brain septal cholinergic neurons in a cell culture

The addition of nerve growth factor to the culture medium increases the size of the bodies of three- and four-dendrite polygonal cholinergic neurons, but not of two-dendrite spindle-shaped neurons. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 1, pp. 102–104, January, 1994 Presented by O. S. Adrianov, Member of the Russian Academy of Medical Sciences     

Effect of insulin and adrenocorticotropic hormone on rat brain cortex in the early postnatal period

Administration of insulin and adrenocorticotropic hormone to 1-, 2-, and 3-day-old rats leads to an increase in the RNA and total protein contents of cortical neurons, while administration of adrenocorticotropic hormone alone increases the number of dying neurons in layer V of the cortex. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 9, pp. 305–307, September, 1995 Presented by V. A. Trufakin, Member of the Russian Academy of Medical Sciences     

Effects of the membrane stabilizer ajmaline and the local anesthetic trimecaine on the pharmacological effects of strophanthinin vivo andin vitro

Under conditions of simulated circulation failure in rats ajmaline increases tolerance for strophanthin cardiotoxicity to a greater extent than trimecaine. In isolated preparations of frog myocardium both antiarrhythmic agents somewhat weaken the inotropic effect of the cardiac glycoside and virtually do not influence its chronotropic effect. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 1, pp. 59–61, January, 1994. Presented by P. V. Sergeev, Member of the Russian Academy of Medical Sciences     

Stimulation of peritoneal macrophage activity in rats with experimental peritonitis during transfusion of UV-irradiated blood

Three transfusions of blood irradiated at 254 nm induce an increase of phagocytic activity of peritoneal macrophages in rats with peritonitis in comparison with infusion of intact blood. Addition of aspirin, an inhibitor of enzymatic peroxidation of lipids, to the irradiated portion of the blood before irradiation abolishes this stimulating effect. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 2, pp. 140–142, February, 1994 Presented by Yu. A. Vladimirov, 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     

Morphofunctional aspects of liver regeneration in experimental correction of toxic hepatitis

It is demonstrated that cytoplasmic extract of rat pup liver stimulates cellular and intracellular regeneration of hepatocytes exposed to the toxic agent CCl₄. Injection of liver cytosol stabilizes lysosomal membranes, increases the coefficient of energy efficiency of mitochondria, and activates proliferation of polyploid hepatocytes. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 6, pp. 656–659, June, 1995 Presented by D. S. Sarkisov, Member of the Russian Academy of Medical Sciences     

Study of cardioprotective effect of α-tocopherol and panthenol using an experimental model of ischemized-reperfused isolated heart

Using an experimental ischemia-reperfusion model it is found that combined treatment with α-tocopherol and panthenol markedly increases the content of endogenous antioxidant tocopherol during total ischemia and reperfusion, i.e., it improves the antioxidant state of the postischemized myocardium, thus preventing possible damage caused by stepped-up production of active oxygen forms during reoxygenation. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 6, pp. 574–576, June, 1994 Presented by P. V. Sergeev, Member of the Russian Academy of Medical Sciences     

Effect of salicylates on the toxicity of GABA-lytics in mice

Preliminary injection of aspirin and salicylic acid increases the toxicity of picrotoxin, but not of bicuculline. Aspirin inhibits binding of³H-diazepam and N-methyl-³H-methylphenazepam with membranes from the brain of intact mice. In view of the fact that salicylates reduce the content and sorption capacity of serum albumin, this protein can be assumed to be involved in the detoxication of picrotoxin. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 6, pp. 619–620, June, 1995     

A method for monitoring toxic damage to the liver,based on measurement of total water and its magnetic relaxation characteristics

Acute poisoning of rats with the hepatotropic poison tetrachloromethane was accompanied by increases in the liver content of total water and its spin-lattice (T ₁) and spin-spin (T ₂) relaxation times and by a decrease in theT ₁/T ₂ ratio, with reversal of the correlation betweenT ₁ andT ₂. The antihypoxic agent sodium γ-oxybutyrate normalized water metabolism in the liver almost completely. It is concluded that total water content andT ₁ are the more informative parameters for monitoring both toxic liver damage and the efficacy of its pharmacological correction. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 12, pp. 584–586, December, 1995 Presented by Yu. A. Vladimirov, Member of the Russian Academy of Medical Sciences     

Binding of3H-diazepam in rat brain eleven months after termination of corazole kindling

Binding of³H-diazepam in rat cerebellum decreases by 14% (p<0.05) 11 months after termination of kindling and one day after injection of a test dose of corazole (30 mg/kg), while it increases by 19.5% after a single injection of a convulsive dose of corazole (50–75 mg/kg). No changes are found in the cortex. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 2, pp. 135–137, February, 1994 Presented by G. N. Kryzhanovskii, Member of the Russian Academy of Medical Sciences     

Regeneration of the liver after partial hepatectomy with a beam of ionized plasma

Eighty guinea pigs underwent resection of the left lateral lobe of the liver, performed with a beam of ionized plasma. Morphological analysis 32 and 45 hours after partial hepatectomy revealed minor damage to the parenchyma to a depth of 300–400 μ. Autoradiography showed proliferative activity in the organ to occur in the early post-operative period. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 4, pp. 431–432, April, 1995 Presented by B. T. Velichkovskii, Member of the Russian Academy of Medical Sciences