Gastric mucosal lesions caused in rats of different strains by emotional stress,and the protective effect of interleukin 1β

Acute emotional stress results in damage to gastric mucous membranes in August, Wag, and particularly Wistar rats. The damage is less severe in rats preinjected with inter-leukin 1β into a lateral ventricle of the cerebrum. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 3, pp. 238–239, March, 1994     

Adaptation to altitude hypoxia limits lipid peroxidation during inflammation and stress

Preadaptation of rats to altitude hypoxia results in reduced activation of lipid peroxidation during subsequent stress, inflammation, or both, as compared to hypoxiaunadapted animals, with the result that secondary changes in organs and tissues of adapted rats are much less pronounced and conditions are created for alleviating the acute inflammation and the stress reaction. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 6, pp. 590–593, June, 1995 Presented by E. D. Gol'dberg, Member of the Russian Academy of Medical Sciences     

Morphofunctional characteristics of connective tissue in emotionally stressed august and wistar rats

August rats, which are predisposed to emotional stress, are shown to differ from Wistar rats, which are not so predisposed, in the morphofunctional organization of lymphoid and connective tissues. In August as compared to Wistar rats, the lymphoid tissue of the spleen, trachea, bronchi, intestine, and lymph nodes is less abundant, the pancreatic insular apparatus is developed much better, and loose connective tissue contains more mast cells without signs of degranulation. Emotional stress leads, in both strains, to strong connective tissue congestion, massive hemorrhages, edema of loose connective tissue in the renal medullary substance and in the liver, focal or focal/confluent connective tissue metachromasia, and progressive mast cell degranulation. These changes are all more pronounced in August rats. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 6, pp. 571–573, June, 1995     

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     

Morphological manifestations of hereditary hypertrophic cardiomyopathy in W/SSM rats

A W/SSM strain of rats with hereditary hypertrophic cardiomyopathy has been created by inbreeding Wistar rats selected for an increased, sensitivity to the cataractogenic effect of high doses of galactose. It is shown that myocardial hypertrophy attended by a diffuse stroma collagenization, focal sclerotic changes, and signs of, chronic heart failure spontaneously develops in these animals. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 8, pp. 203–207, August, 1994     

Morphogenesis of a canalicular-hypertensive model of pancreatitis

A rat model of acute pancreatitis is presented. Its conformity to the pancreatic changes during human pancreatitis is shown. The morphology of experimental pancreatitis development in rats is studied. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 1, pp. 89–91, January, 1995     

Morphology of the adrenal cortex in normo- and hypertensive rats under conditions of salt loading

Adrenocorticocytes of normotensive Wistar rats and rats with spontaneous hypertension (SHR) were examined by light and electron microscopy. It is proposed that the adrenocorticocytes of rats living under conditions of permanent functional overstrain (hypertrophy of all zones) are more “fragile” during changes of water-salt homeostasis, in whose regulation they actively participate. Analysis of correlations confirmed a reduction of the adaptive potential of SHR rats to changes in water-salt homeostasis: an increase and enhancement of the bonds between adrenocorticocyte structures and a decrease of degrees of freedom. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 12, pp. 648–650, December, 1994 Presented by D. S. Sarkisov, Member of the Russian Academy of Medical Sciences     

Differences in the neuronal activity of dorsal horn neurons between rats developing and not developing a pain syndrome after sciatic nerve transection

After sciatic nerve transection, a generator of pathologically enhanced excitation is formed in dorsal spinal cord horns at the transection side in rats that have developed a pain syndrome but not in those that have not; in the latter rats, plastic changes occur instead and lead to intensified afferent inputs from tissues of the affected limb to the contralateral dorsal horns. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 5, pp. 470–474, May, 1995     

Role of glycolysis in the maintenance of the energy-synthesizing function of hepatocytes from rats adapted and nonadapted to hypoxia at different oxygen concentrations

It is demonstrated that the lactate-Po₂ dependence is the same in hepatocytes of rats with high and low resistance to hypoxia and does not correlate with phasic changes in the ATP concentration in the 890–50 μM O₂ region. Strong activation of lactate formation against the background of ATP decrease indicates that glycolysis is not the major mechanism determining the steady-state ATP level in the cell and affecting the ATP-Po₂ relationship in a wide range of oxygen concentrations. The intensity of glycolysis in hepatocytes of rats with high resistance to hypoxia is markedly increased after periodic adaptation to hypoxia but remains practically unchanged in the hepatocytes of low-resistance rats. This indicates that fundamentally different compensatory mechanisms are involved in this process in the liver of high- and low-resistance rats. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 1, pp. 28–32, January, 1995     

Effect of immunization against alcohol dehydrogenase on the behavior of white rats

Active immunization of white rats with alcohol dehydrogenase (horse ADH-1), a major ethanol-metabolizing enzyme shown to cause considerable and long-term inhibition of alcohol consumption, did not have adverse effects on their behavior. Rather, the rats showed enhanced motor and orienting-exploratory activities, developed conditioned responses (with both positive and negative reinforcements) more readily, and spent less time in a state of immobilization in the forced swimming test as compared with nonimmunized controls. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 10, pp. 349–351, October, 1994     

Immunological correlation between morphine tolerance and the effect of naloxone in rats of different age

In 3–6-week-old morphine-sensitive rats, in which morphine injection produced an analgetic effect, the serum titer of antimorphine antibodies 24 h postinjection is less than half that observed in morphine-resistant animals. Administration of naloxone to morphine-sensitive rats induces hyperalgesia and considerably raises the serum titer of antimorphine antibodies. Chronic injections of the same dose of morphine, which cause its analgetic effect to disappear, increase the titer of antibodies in morphine-sensitive rats 2-fold. In morphine-resistant rats naloxone produces an analgetic effect followed by its gradual decay and disappearance in the course of chronic administration. Subsequent administration of morphine induces analgesia, raises the titer of antimorphine antibodies, and lowers the titer of antiidiotypic antibodies. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 121, N ^o 1, pp. 67–70, January, 1996 Presented by K. V. Sudakov, Member of the Russian Academy of Medical Sciences     

Changes in the blood-brain barrier in experimental cirrhosis of the liver

Light and electron microscopic studies on Wistar rats with experimental cirrhosis produced by tetrachloromethane demonstrate strongly marked changes in the blood-brain barrier, particularly in capillaries and vascular pedicles of astrocytes. It is pointed out that destabilization of the blood-brain barrier favors the transfer of cerebral toxins and other metabolic poisons across this barrier. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 7, pp. 86–88, July, 1994 Presented by I. P. Ashmarin, Member of the Russian Academy of Medical Sciences     

Effect of prenatal hypoxia on DNA synthesis in the tracheal epithelium and LPO-AOD system in the lungs of newborn rats

Newborn rats euthanized 24 h after birth were examined. The rats were born to females exposed to chronic hypobaric hypoxia on days 14–19 of gestation. The index of nuclei labeled with³H-thymidine in the tracheal epithelium of newborn rats exposed to prenatal hypoxia was 3 times lower than in the control. The LPO level was higher in posthypoxic animals than in intact rats. Prenatal hypoxia led to the suppression of antioxidant defense in the lungs of newborn rats. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 5, pp. 531–533, May, 1994     

Effect of dimethylsulfate on the structure and cytoarchitectonics of rat thymus

Changes of structure and cell ratios of different functional zones in the thymus under conditions of long-term dimethylsulfate administration at 0.1 and 2.0 mg/m³ on the organism are studied morphometrically on histological preparations from Wistar rats. Cyclic reactions of the thymus to the toxic substance are found to be due to compensatory processes. It is shown that the nature of the reaction does not depend on the concentration of toxic substance but that the extent of changes is a function of the dimethylsulfate concentration. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 1, pp. 96–100, January, 1995     

Effects of adaptation to hypoxia on cytochrome levels in the brain and liver of rats

After a prolonged (for 30 days) adaptation of rats to intermittent hypoxia, their brains contained lowered levels of mitochondrial cytochromes, despite an increase in the number of mitochondria in the brain tissue mass, along with similar levels of high-energy compounds and more protein as compaired to the brains of unadapted controls. A mitochondrial population with novel properties presumably emerged in the brain. These effects were all more strongly marked in rats with an initially low resistance to hypoxia. In the liver of hypoxiaadapted animals, unlike in their brain, cytochrome levels in the mitochondrial and microsomal redox chains were lowered and the biogenesis of mitochondria was much less intensive. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 12, pp. 576–579, December, 1995     

Content of 2,3-diphosphoglycerate and adenosine triphosphate in erythrocytes and the acid-base balance in adult and newborn rats during acute hypoxia

It is shown that in deep acute hypoxic hypoxia the 2,3-diphosphoglycerate content is reduced and the adenosine triphosphate content unchanged in the erythrocytes of newborn rats. Under the same conditions adult animals show an increase of 2,3-diphosphoglycerate and a drop in the adenosine triphosphate content in the erythrocytes. The importance of these changes is discussed in terms of the mechanisms regulating the oxygen-transporting function of erythrocytes during acute hypoxic hypoxia in newborn and adult animals. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 6, pp. 631–633, June, 1995 Presented by M. Ya. Studenikin, Member of the Russian Academy of Medical Sciences     

Induction of the monooxygenase system in rat blood neutrophils by methylcholanthrene and sovolin vivo and its effects on the properties of these cells

The xenobiotics methylcholanthrene and sovol (the latter being a mixture of polychlorinated biphenyls), which are monooxygenase system inducers, were tested for their effect on the respiratory burst in rat blood neutrophilsin vivo. The chemiluminescence accompanying this burst was more intensive in the neutrophils of rats treated with methylcholanthrene or sovol than in untreated rats. Observed changes in the 2A_max parameter of the electron paramagnetic resonance spectrum recorded for the spin probe 5-doxyl stearate in the presence of neutrophils indicated that methylcholanthrene and sovol can exert a direct effect on the viscous properties of neutrophil plasma membranesin vivo. These changes were similar in direction to those in the intensity of chemiluminescence during the respiratory burst in neutrophils. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 11, pp. 485–488, November, 1995 Presented by I. P. Ashmarin, Member of the Russian Academy of Medical Sciences     

A preliminary course of transauricular electrostimulation mitigates impairment of cardiac contractile function in rats with myocardial infarction

A course of transauricular electrostimulation (TES) consisting of 10 sessions was administered to rats before the induction of myocardial infarction by Selye's method and to rats that were left intact. In the latter anirnals, the electrostimulation did not influence cardiac contractile function at rest (as judged by heart rate, developed pressure, and Katz's index), but exerted beneficial chronotropic and inotropic effects during the maximum isometric tension produced by compression of the ascending aorta. In the TES-pretreated rats with a 2-day-old myocardial infarct, cardiac contractile function was depressed significantly less, both at rest and during isometric tension, than in infarcted rats not exposed to TES. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 12, pp. 568–571, December, 1995 Presented by G. N. Kryzhanovskii, Member of the Russian Academy of Medical Sciences     

Ultrastructural changes in the interstitial cells of the renal medulla during endotoxin shock

Ultrastructural modifications of renomedullar interstitial cells are described at different stages of experimental endotoxemia in rats and dogs. The dynamics of changes occurring in organelles, lipid granules (precursors of prostaglandins), and medullar capillaries is presented. It is suggested that the alterations in these granules during endotoxin shock are associated with the synthesis, accumulation, and secretion of their precursors in interstitial cells. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 7, pp. 107–112, July, 1995 Presented by D. S. Sarkisov, Member of the Russian Academy of Medical Sciences     

Comparative pharmacological analysis of the M-cholinoreceptors inDaphnia and rats

The efficacy of M-cholinolytics in the prevention of the toxic effect of some cholinomimetics is comparatively assessed in experiments onDaphnia magna and albino rats. It is proposed that the M-cholinoreceptor population is heterogeneous inDaphnia as well as in rats. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 5, pp. 497–499, May, 1994 Presented by S. N. Golikov, Member of the Russian Academy of Medical Sciences