Potassium and sodium ions in the nerve tissue of emotionally overstrained rabbits

Measurement of K⁺ and Na⁺ concentrations in samples of individual brain nuclei and in ganglia of the autonomic nervous system from rabbits subjected to severe emotional stress (ES) through aperiodic stimulation of ventromedial hypothalamic nuclei and electrocutaneous stimulation revealed significantly altered levels of these ions in locus ceruleus samples from animals predisposed to ES-induced cardiovascular disorders and in samples of neurons of the caudal part of the brainstem from those resistant to such disorders. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, No 8, pp. 129–131, August, 1994 Presented by K. V. Sudakov, Member of the Russian Academy of Medical Sciences     

The sympathetic nervous system is not involved in the development of atropine tachycardia

There is a consensus that the vagus nerve produces a permanent (tonic) inhibitory effect on heart activity. However, some recent experimental findings attest that the vagus tone is not pronounced and suggest that excittion of the sympathico-adrenal system is the cause of atropine tachycardia. We found in acute and chronic experiments that the blockage of the sympathetic nervous system does not abolish atropine- and methacin-induced tachycardia. At rest heart activity is regulated by the vagus as well as by humoral agents circulating in the blood. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 9, pp. 234–237, September, 1994 Presented by A. A. Ado, Member of the Russian Academy of Medical Sciences     

The sympathetic nervous system is not implicated in the development of vagotomy-induced tachycardia

It is believed by a number of investigators that vagal tone is weak and that tachycardia after bilateral vagotomy results from excitation of the sympathetic nervous system. However, this study shows that postvagotomy tachycardia develops without the participation of the sympathetic nervous system and decreases in the course of time spontaneously in animals with uninterrupted sympathetic nervous pathways. The degree of vagal tone is influenced by the type and depth of anesthesia. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 8, pp. 125–128, August, 1995 Presented by K. V. Sudakov, Member of the Russian Academy of Medical Sciences     

Disturbances in the integrative activity of the rat brain after bilateral focal compression ischemia of the frontal cortex

Pathomorphological changes and disturbances in the integrative activity of the central nervous system of rats are studied after bilateral compression ischemia of the frontal cortex. Bilateral compression of the frontal cortex is shown to result in the formation of limited foci of ischemic necroses in the cortex, which are surrounded by the perifocal zone. This is attended by reduced horizontal motor activity in the “open field” test, as well as by a reduced latency of the conditioned passive avoidance response. The motor activity of operated animals is restored on day 14 postoperation, correlating with regeneration of some damaged neurons in the perifocal zone, whereas the latency of the conditioned passive avoidance response remains markedly reduced. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 12, pp. 568–571, December, 1994 Presented by O. S. Adrianov, Member of the Russian Academy of Medical Sciences     

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     

Transplantation of fetal nerve cells from insects to the brain of amphibians and mammals

Cells of the neural primordia of the Notch mutant ofDrosophila melanogaster are transplanted to the neural tube of four amphibian species and two mammalian species. It is shown that cells of the neural primordia of drosophila survive and differentiate in the amphibian and mammalian brain. Differentiated cells of the transplant establish axon-dendrite junctions with cells of the recipient and penetrate into the structures of its brain. Tailed amphibians die several days after xenotransplantation. Transplantation of drosophila cells to the nervous system of tailless amphibians and mammals does not cause developmental abnormalities or death of the animals. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 4, pp. 364–368, April, 1994 Presented by N. K. Permyakov, Member of the Russian Academy of Medical Sciences     

Adaptation to periodic hypoxia and a diet supplemented with polyunsaturated class ω-3 fatty acids enhance the resistance of Ca2+ transport in the myocardial sarcoplasmic reticulum to free-radical oxidation

The relationship between the level of accumulation of lipid peroxidation products and the status of the Ca²⁺-transporting system in the sarcoplasmic reticulum of the rat myocardium is studied against the background of two cardioprotective factors, namely adaptation to periodic hypoxia and a diet enriched in polyunsaturated fatty acids of the ω-3 class. It is shown that the diet leads to an increase of level of lipid peroxidation products by 1.8 times in the heart and by 19 times in the liver, whereas a adaptation has no effect on the level of lipid peroxidation products in either of these organs. At the same time, the combined action of both factors considerably enhances the resistance of the myocardial Ca²⁺-transporting system to free radical-induced oxidation. Inin vitro experiments it is shown that adaptation to periodic hypoxia results in a more than twofold deceleration of Ca²⁺ transport inhibition during the oxidation induction by the Fe²⁺/ascorbate system; the diet causes a 3.5-fold deceleration of such inhibition. The results show that the accumulation of a high level of lipid peroxidation products is not always followed by damage to the Ca²⁺-transporting system in the myocardial sarcoplasmic reticulum. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 7, pp. 42–45, July, 1995 Presented by G. N. Kryzhanovskii, Member of the Russian Academy of Medical Sciences     

Dynorphin A (1-17), Met-enkephalin-Arg6-Phe7 and substance P (1-11) levels in the brain of mice with different levels of ethanol consumption

Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 116, N ^o 8, pp. 177–178, August, 1993     

Ca2+ transport of the skeletal muscle sarcoplasmic reticulum during readaptation of rats after a 40-day load relief on the hind paws

The rate of Ca²⁺ accumulation in the sarcoplasmic reticulum of the skeletal muscle (m. gastrocnemius lateralis, m. vastus medialis, andm. soleus) is studied in rats under conditions of functional off-loading of the hind paws (suspending animals by the tail). The rate of Ca²⁺ transport in the sarcoplasmic reticulum is shown to be stepped up in all these muscles. In the sarcoplasmic reticulum ofm. gastrocnemius lateralis andm. vastus medialis the Ca²⁺ transport rate reliably drops, which does not occur inm. soleus. During a 2-week period of readaptation of animals suspended for 40 days, the Ca²⁺-transporting function of them. soleus sarcoplasmic reticulum gradually recovers to reach the control values, whereas the time course of recovery of Ca²⁺-pump activity in the sarcoplasmic reticulum ofm. gastrocnemius lateralis andm. vastus medialis has a phasic pattern. Translated fromByulleten' Eksperimental'noi Biologii i Meditsity, Vol. 118, N ^o 12, pp. 591–595, December, 1994 Presented by A. I. Grigor'ev, Member of the Russian Academy of Medical Sciences     

The effect of delta-sleep-inducing peptide on the Ca-transporting system of the sarcoplasmic reticulum and activity of the myocardial antioxidant enzymes

It is demonstrated that immobilization stress against the background of lowered catalase activity impairs the function of the sarcoplasmic reticulum Ca pump, particularly at high Ca²⁺ levels. the membranes of intracellular Ca²⁺ depots are destroyed much more rapidly than in the control, which results in Ca²⁺ release. Administration of delta sleep-inducing peptide to control animals results in a 30% increase in catalase activity for an unchanged level of superoxide dismusase and markedly improves the function of the Ca-transporting system at elevated levels of free Ca²⁺. A long-term stress after administration of the peptide not only causes no damage to the Ca-transporting system but actually increases its efficiency (compared with the control) at a high catalase level. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 121, N ^o 3, pp. 248–251, March, 1996 Presented by G. N. Kryzhanovskii, Member of the Russian Academy of Medical Sciences     

Effect of amiridine and tacrine on potassium currents in the nerve fiber

Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 116, N ^o 10, pp. 397–400, October, 1993     

Fibronectin as a compensating factor in the natural cytotoxicity system in interferon-dependent immunodeficiency

The cytotoxicity of natural killer cells (NK) against³H-uridine-labeled target cells (TC, human erythromyeloleukosis cells K-562) and the intensity of conjugate formation in the NK:TC system in the presence of γ-interferon, C-reactive protein, and human fibronectin are studiedin vitro in 14 patients with multiple sclerosis. It is shown that γ-interferon and C-reactive protein decrease the cytotoxic activity of NK with a simultaneous stimulation of conjugate formation in the NK:TC system. The correlation between the studied parameters becomes weaker. Human fibronectin induces collateral changes in the activity of NK and in the number of effector:target conjugates formed in the natural cytotoxicity reaction. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 7, pp. 67–70, July, 1994     

Na+/H+ countertransport and calcium exchange in peripheral blood cells of healthy subjects and patients with chronic heart failure

A comparative study is performed of Na⁺/H⁺ exchange and Ca²⁻ mobilization in erythrocytes and platelets of patients with stage I–II chronic heart failure caused by dilative cardiomyopathy and ischemic heart disease. A significant rise in the Na⁺/H⁺ exchange rate is found in the cells of chronic heart failure patients, which correlates with an elevated erythrocyte and platelet concentration of Ca²⁺ and an increased “calcium” response of platelets to inductors. The findings testify to a certain functional relationship between various cation-transporting cellular systems whose change in properties upon chronic heart failure can play an important pathogenic role. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 12, pp. 572–575, December, 1994     

Effect of semax heptapeptide on the human electroencephalogram

The effect of the new regulatory peptide Semax (ACTH_4–10 fragment) on the electroencephalogram of a healthy person was studied. Semax was administered at 0.5 mg/kg intranasally in 9 volunteers without causing any nervous system pathology. The control group comprised 6 examinees treated in the same way with distilled water. The effect of Semax manifested itself on the electroencephalogram as a boost of biopotential strength in all ranges but especially in that of the α-rhythm, the zonal differences of which were enhanced, without any pathological signs being evident. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 121, N ^o 1, pp. 116–117, January, 1996 Presented by I. P. Ashmarin, 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     

Patterns of interaction between the immune and endocrine systems in the manifestation of hereditary autoimmune disorders in NZB mice

Specific features of immune-endocrine interrelationships and of pituitary-adrenal system functioning are studied in NZB mice with hereditary autoimmune pathology. It is established that the development of disease is accompanied by a weakened response to stress, reduced blood corticosteroid level, and decreased adrenal reactivity to exogenous adrenocorticotropic hormone. Moreover, a loss of sensitivity to interleukin-2 is observed. These facts provide evidence of disturbed interaction between the immune and endocrine systems as well as of inhibition of pituitary-adrenal system activity as the autoimmune disease develops. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 4, pp. 394–397, April, 1995     

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     

Altered activity of respiratory chain enzymes in mitochondria of peripheral blood lymphocytes after irradiation in rats

The effect of ionizing radiation on the activity of succinate dehydrogenase (complex II) and succinate-cytochrome C-oxidoreductase in peripheral blood lymphocytes is studied on rats exposed to whole-body γ-irradiation in doses of 9.5–10.5 Gy. On day 5 after irradiation, when the number of lymphocytes is sharply reduced, enzyme activity in the remaining population is found to be reliably increased. These changes are not related to biological cycles. It is assumed that most of the survivors after high-dose irradiation are the cell populations maintaining a high level of oxidative phosphorylation in mitochondria. Translated fromByulleten' Eksperimental'noi Giologii i Meditsiny, Vol. 120, N ^o . 8, pp. 158–159, August, 1995 Presented by D. S. Sarkisov, Member of the Russian Academy of Medical Sciences     

Effect of aminooxyacetic acid on the antidote activity of diazepam under the action of GABA-lytics

Pretreatment of mice with aminooxyacetic acid enhances the antidote activity of diazepam against picrotoxin but not bicuculline. It is claimed that GABA-transaminase inhibitors may be promising candidates as an antidote in complex therapy of seizures induced by GABA-lytics blocking the chloride ionophore. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 4, pp. 441–443, April, 1994     

Threshold of seizure activity of the brain and higher nervous activity in the postresuscitation period for intracerebral allotransplantation of fetal neocortex tissue

The threshold of seizure activity of the brain, long-term memory, and learning ability are studied in Wistar rats for bilateral transplantation of fetal nervous tissue in area CA1 of the hippocampus. The grafts are performed on the 2nd, 7th, 14th and 30th days after clinical death caused by asphyxia. A neurotransplantation performed on the 2nd day of the postresuscitation period is found to prevent seizure activity, whereas that performed on the 7th–14th days results in a sharp decline or cessation of spontaneous and induced epileptiform convulsive seizures, prolonged preservation of the long-term memory trace, an improvement of learning ability, and a lessening of defensive and phobic behavior in a large proportion of the animals. Translated fromByulleten's Eksperimental'noi Biologii i Meditsiny, Vol. 121, N ^o 2, pp. 234–237, February, 1996 Presented by V. A. Negovskii, Member of the Russian Academy of Medical Sciences