Effect of hemodilution and hemoconcentration on postischemic alterations of microvessels in rabbit paired auricles

Morphometric parameters of microvessels in paired rabbit ears and blood sampled from the internal vein were studied after ischemia reproduced under conditions of prior hemodilution and hemoconcentration. In hemodilution the postischemic alterations were found to be more pronounced in microvessels of the left ear, while for the right the same was true for rheological characteristics of the outflowing blood. Under conditions of hemoconcentration after ischemia the changes in rheological indexes were more marked on the left and in vasomotor indexes on the right. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 121, N ^o 3, pp. 352–354, March, 1996 Presented by V. V. Kupriyanov, Member of the Russian Academy of Medical Sciences     

High-molecular-weight polyethylene oxide improves blood flow through stenosed carotid artery

Intravenous injection of 0.1 mg/kg high-molecular-weight polyethylene oxide (molecular weight 5.8×10⁶) to narcotized cats with experimental stenosis of the right carotid artery considerably improved blood flow and reduce blood pressure in stenosed vessel. This normalizes cerebral blood supply via both carotid arteries despite a decrease in systemic blood pressure. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 126, No. 7, pp. 60–62, July, 1998     

Effect of the organophosphorus compound anthio on the pulmonary and systemic circulation of non-narcotized cats

Experiments on cats demonstrate the capacity of alert animals to compensate for disorders in pulmonary and systemic hemodynamics caused by organophosphorus compounds. Heart rate, systemic arterial pressure, and total peripheral resistance completely normalize on day 3 after exposure. Pulmonary vascular resistance and pulmonary blood pressure remain negligibly increased. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 3, pp. 276–279, March, 1995 Presented by N. A. Agadzhanyan, Member of the Russian Academy of Medical Sciences     

Early blood system response to infectious agents

Early systemic blood responses to various infectious agents (Staphylococcus aureus, Escherichia coli, herpes simplex virus) were studied. Nonspecific changes in the blood typical of stress syndrome and enhanced apoptosis of in the bone marrow and lymphoid organs were seen 6 hours after injection of bacterial agents. Injection ofE. coli induced marked depression of hemopoietic precursors and extensive apoptosis of bone marrow, thymic, and splenic cells. Herpes simplex virus induced only minor changes in the blood system. Translated fromByullenten' Eksperimental'noi Biologii i Meditsiny, Vol. 128, No. 10, pp. 425–428, October, 1999     

Adaptive structures of arterial bed in norm and in modeled congenital heart failure

Material from 85 dogs with modeled congenital heart failure and from 20 control dogs was studied. Adaptive structures were revealed in the pulmonary and systemic circulation. These structures are formed by smooth muscle cells, are located at arterial bifurcations, compensate for increased hemodynamic load, and regulate blood flow in the vascular bed of a given internal organ. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 125, No. 6, pp. 713–716, June, 1998     

Dermaprotecting properties of sodium succinate under conditions of impaired circulation

Sodium succinate improves the survival of a skin graft in mice, rats, and dogs normalizes histamine and serotonin concentrations in the epidermis and blood, exhibits antitoxic activity, improves microcirculation in the skin, brain, heart, kidneys, and testes without any appreciable effect on systemic arterial pressure, cardiac function, and liver blood flow in rats. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 126, No. 10, pp. 420–424, October, 1998     

Effect of neurotropin on regional cerebral blood flow and systemic blood pressure

Experiments on rabbits show that neurotropin has no effect on regional cerebral flow and systemic blood pressure under normal conditions, but reduces regional cerebral flow in partial circulatory hypoxia (ischemia) and recirculation. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 125, No. 6, pp. 612–614, June, 1998     

Prevention of systemic hemodynamic changes with taurine

Intravenous infusion of taurine prevents a decrease in cardiac pump function caused by electric stimulation of the aortic arch and promotes recovery of systemic blood flow and total peripheral resistance. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 127, No. 3, pp. 282–284, March, 1999     

Correlation between blood pressure and parameters of systemic hemodynamics during pressor and depressor effects of the ventral medulla oblongata

Correlation between blood pressure and parameters of systemic hemodynamics was studied on cats using electrical stimulation of the ventral medulla oblongata. Changes in blood pressure induced by presoor activation were related to venous hemodynamics in the anterior rather than posterior vena cava. Venous blood flow is assumed to be involved in hemodynamic changes caused by stimulation of pressor centers but not depressor centers in the ventral medulla oblongata. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 129, No. 1, pp. 16–19, January, 2000     

Adaptation to periodic high-altitude hypoxia inhibits baroreflex vagal bradycardia in rats

A 3-week course of adaptation to high-altitude hypoxia (4500 m above sea level) inhibited baroreflex avagal bradycardia induced by a rapid rise of systemic blood pressure in conscious rats. Bradycardic responses to electrical stimulation of peripheral end of the right vagus nerve and methacholine (M₂ muscarinic receptor agonist) in hypoxia-adapted rats did not differ from the control. It is concluded that hypoxia inhibits baroreflex vagal bradycardia by acting on a central element of the baroreceptor reflex arch Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 129, No. 4, pp. 386–389, April, 2000     

Mechanisms of cardioprotective effect of estradiol

Estradiol suppresses contractile activity of isolated atrium, inhibits LPO, and stabilizes lysosomal membranes in rat heart. A small content (3.1–16.5 fmol/mg protein) of estradiol-binding sites is detected in the cytoplasm of ventricular cells from dogs and rats of both sexes. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 129, No. 1, pp. 67–69, January, 2000     

Synthesis and hemodynamic effects of a new endothelin-converting enzyme inhibitor

A new endothelin-converting enzyme inhibitor PP-35 including N^α-benzylsuccinyl group and Leu-Trp-OH dipeptide is synthesized. Similarly to phosphoramidon substance PP-35 abolishes elevation of systemic blood pressure and heart rate decrease in normotensive rats in response to bolus injection of big endothelin-1. Hemodynamic responses to endothelin-1 remain unchanged. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 126, No. 11, pp. 526–529, November, 1998     

DNA damage in mononuclear blood cells of patients with systemic lupus erythematosus

Alkaline electrophoresis of DNA in individual cells (the DNA comet method) showed that the mean DNA damage is increased in blood mononuclear cells and the proportion of cells containing damaged DNA is higher in patients with systemic lupus erythematosus than in healthy donors; the number of hypodiploid cells is increased, indicating intensified apoptosis. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 125, No. 1, pp. 75–78, January, 1998     

Effect of toxin of burned skin on the state of the hemodynamics in rats

Toxin for burned rat skin, purified immunochemically, possesses definite physiological activity against the cardiovascular system of homologous animals. If injected into the blood stream, the toxin lowers the systemic arterial pressure within 2 h from 125±7 to 74±8 mm Hg. The development of systemic hypotension is accompanied by secondary disorders of the microcirculation in the mesentery of the small intestine, characterized by constriction of the arterioles, slowing of the blood flow along the venules, and reduction of the capillary blood flow.Laboratory of Pathological Physiology, Central Institute of Hematology and Blood Transfusion, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. A. Fedorov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 3, pp. 275–276, March, 1976.     

Rate of diadenosine polyphosphate degradation by various guinea pig tissues

High-performance liquid chromatography and colorimetry of inorganic phosphorus show that in the presence of muscle tissues from the guinea pig bladder, seminal duct, small intestine, longitudinal cord of the cecum, and right atrium all diadenosine polyphosphates with a common formula APnA (n=2–6) are degraded more slowly than ATP. The rate of AP_nA cleavage is highest in experiments with the small intestinal and right atrial tissues. P2-purine receptor antagonist suramin inhibits degradation of AP3A by right atrial tissue and does not modify degradation of other APnA. Enzymatic stability of endogenous APnA is apparently the principal condition for manifestation of their biological effects. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 127, No. 2, pp. 207–210, February, 1999     

Sensitivity of the respiratory system to oxygen in cats with activated GABAergic brain structures

Activation of the GABAergic system in pentobarbital-anesthetized random-bred male and female cats by intravenous injection of GABA agonist (sodium oxybutyrate or phenibut) increases the contribution of oxygen to the regulation of respiration. Hypoxia stimulates, while hyperoxia inhibits pulmonary ventilation in cats regardless of whether their breathing is of the periodic apneustic or “machinelike” type. Their respiratory response to hypoxia and hyperoxia is more pronounced than that observed before sodium oxybutyrate of phenibut injection. It is shown that respiratory reactions to these stimuli after administration of the agonists are due not to concomitant changes in the systemic hemodynamics but rather to decreased contribution of carbon dioxide to the regulation of respiration and low oxygen tension in arterial blood. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 123, No. 3, pp. 264–268, March, 1997     

Atrial cardiomyocytes of a heterothermic animal in various physiological states

Hormone-producing cardiomyocytes of the right atrium of suslik were studied in summer and winter periods (the torpidity and spontaneous awake states). The hormone was shown to be intensely synthesized in summer. The intensity of this process decreased during hypothermia and increased during winter spontaneous awakenings. The role of these changes in the maintenance of water and salt homeostasis is discussed. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 126, No. 9, pp. 353–356, September, 1998     

Heteroduplex analysis of Salmonella virulence plasmids and their prevalence in isolates of defined sources

Strains of the Salmonella serovars S. typhimurium, S. enteritidis, S. dublin, and S. choleraesuis harbour large plasmids which are required for extraintestinal colonization after oral infection of mice. Electron microscopic heteroduplex analysis showed that these virulence plasmids share large regions of homology. Nine hundred and eighty-six isolates of different origins were analysed for the presence of these plasmids by using a cloned fragment of a S. choleraesuis virulence plasmid as a gene probe. Virulence plasmids were detected in nearly 100% of strains isolated from animal organs or human blood. Frequencies of detection ranged from 48 to 87% in strains of faecal, food or environmental origin. These results suggest that Salmonella virulence plasmids are required for systemic infections in humans and livestock.     

Effect of nonachlazine on the frequency and amplitude of contractions of the isolated atrium

The effect of the new antianginal drug nonachlazine on the frequency and amplitude of contractions of the isolated atrium of guinea pigs and albino rats was studied. In experiments on the isolated atrium nonachlazine as a rule depresses these parmeters. This effect of the drug on the isolated atrium is evidently due to the direct effect of nonachlazine on the myocardium and on the conducting system of the heart. No species differences were found in the character of the action of nonachlazine.Laboratory of Pharmacology of the Cardiovascular System, Institute of Pharmacology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR, V. V. Zakusov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 3, pp. 298–300, March, 1977.     

Numerical modeling of ventricular filling

The fluid dynamical and physiological assumptions underlying general mathematical modeling of ventricular filling are outlined. We then describe the use of a lumped parameter model and computer simulation to study how the early transmitral velocity profile is affected by isolated changes in ventricular compliance and relaxation, atrial pressure and compliance, and valvular morphology. We show that the transmitral velocity is fundamentally affected by twophysical determinants: the transmitral pressure difference and the net compliance of the atrium and the ventricle. These physical determinants in turn are specified by the variousphysiologic parameters of interest. This approach has shown that peak velocity is most strongly affected by initial left atrial pressure, lowered somewhat by prolonged relaxation, low atrial and ventricular compliance, and systolic dysfunction. Peak acceleration is directly affected by atrial pressure and inversely affected by the time constant of isovolumic relaxation, with little influence of compliance, whereas the deceleration rate is almost purely given by mitral valve area divided by instantaneous atrioventricular compliance at the end of the rapid filling wave.