Peptide Mimetic of BDNF Loop 4 Blocks Behavioral Signs of Morphine Withdrawal Syndrome and Prevents the Increase in ΔFosB Level in the Striatum of Rats.

Activity of compound GSB-106, a low-molecular mimetic of loop 4 of the brain neurotrophic factor (BDNF), was studied in experimental morphine withdrawal syndrome simulated in outbred rats. Single and subchronic (5 intraperitoneal injections) administration of GSB-106 in a dose of 0.1 mg/kg significantly reduced the total index of morphine withdrawal syndrome by 55.2 and 45.6%, respectively. GSB-106 reduced the severity of some behavioral signs (piloerection, gnashing of teeth, wet-dog shaking, and runaway attempts), but had no effect on mechanical allodynia formed in the rats with dependence. Subchronic treatment with GSB-106 prevented the increase in the content of ΔFosB (product of early response gene) in the striatum induced by morphine withdrawal. The results confirmed the concept on the involvement of neurotrophins, specifically BDNF and its analogs, in the mechanisms associated with the formation of opiate dependence.

A Nerve Growth Factor Dipeptide Mimetic Stimulates Neurogenesis and Synaptogenesis in the Hippocampus and Striatum of Adult Rats with Focal Cerebral Ischemia.

The nerve growth factor (NGF) and its mimetics, which have neuroprotective and neuroregenerative properties, are attractive candidates for developing new drugs for brain injury therapy. A dipeptide mimetic of NGF loop 4, bis(N-succinyl-L-glutamyl-L-lysine) hexamethylenediamide (GK-2), developed at the Zakusov Research Institute of Pharmacology, has the NGF-like ability to activate TrkA receptors, but unlike NGF, GK-2 activates mainly the PI3K/AKT pathway associated with neuroprotection and has no effect on the MAPK cascade associated with hyperalgesia, the main side effect of NGF. That GK-2 possesses neuroprotective activity has been observed in various models of cerebral ischemia. GK-2 was found to statistically significantly reduce the cerebral infarct volume in experimental stroke, even at treatment onset 24 h after injury. This suggests that GK-2 possesses neuroregenerative properties, which may be associated with the activation of neurogenesis and/or synaptogenesis. We studied the effect of GK-2 on neurogenesis and synaptogenesis in experimental ischemic stroke caused by transient occlusion of the middle cerebral artery in rats. GK-2 was administered 6 or 24 h after surgery and then once a day for 7 days. One day after the last administration, proliferative activity in the hippocampus and striatum of the affected hemisphere was assessed using Ki67 and synaptogenesis in the striatum was evaluated using synaptophysin and PSD-95. Ki67 immunoreactivity, both in the striatum and in the hippocampus of the ischemic rats, was found to have dropped by approximately 30% compared to that in the sham-operated controls. Synaptic markers - synaptophysin and PSD-95 - were also statistically significantly reduced, by 14 and 29%, respectively. GK-2 in both administration schedules completely restored the level of Ki67 immunoreactivity in the hippocampus and promoted its increase in the striatum. In addition, GK-2 restored the level of the postsynaptic marker PSD-95, with the therapeutic effect amounting to 70% at the start of its administration after 6 h, and promoted restoration of the level of this marker at the start of administration 24 h after an experimental stroke. GK-2 had no effect on the synaptophysin level. These findings suggest that the neurotrophin mimetic GK-2, which mainly activates one of the main Trk receptor signaling pathways PI3K/ AKT, has a stimulating effect on neurogenesis (and, probably, gliogenesis) and synaptogenesis in experimental cerebral ischemia. This effect may explain the protective effect observed at the start of dipeptide administration 24 h after stroke simulation.

Selank, Peptide Analogue of Tuftsin, Protects Against Ethanol-Induced Memory Impairment by Regulating of BDNF Content in the Hippocampus and Prefrontal Cortex in Rats.

The effects of a peptide anxiolytic Selank synthesized on the basis of the endogenous peptide tuftsin on memory impairment and content of brain-derived neurotrophic factor (BDNF) in brain structures were analyzed in outbred rats receiving 10% ethanol as the only source of fluid for 30 weeks. In the object recognition test, Selank (0.3 mg/kg a day, 7 days, intraperitoneally) produced a cognitive-stimulating effect in 9 months rats not exposed to ethanol (p<0.05) and prevented the formation of ethanol-induced memory and attention disturbances (p<0.01) developing during alcohol withdrawal. In ex vivo experiments, Selank prevented ethanol-induced increase in BDNF content in the hippocampus and frontal cortex (p<0.05). These results indicate positive effects of the tuftsin analogue on age-related memory disturbances associated with chronic alcohol intoxication and confirm the involvement of the neurotrophin mechanism related to BDNF production into the effect of Selank.

Effect of Nitric Oxide Synthesis Blockade on the Morphology of Langerhans Islets in August and Wistar Rats with Acute Alloxan Diabetes.

Alloxan diabetes was modeled in August rats with high activity of the NO system and in Wistar rats, and the effects of NO system blockade (by a course treatment with L-NNA) on Langerhans islet ß cells were studied in 15 days. The toxic effects of diabetes on the rat ß cells and islets were similar: the content of active ß cells in the islets decreased to 15-20%, the number of islets to 24-29% of control. A course of L-NNA reduced the ß cell and islet death, in August cells greater than in Wistar: the number of islets in August rats was restored to 81%, in Wistar rats to 60% of initial level; the activity of ß cells remained at the control level in the former and 2-fold lower than in the control in the latter. It seems that a less pronounced protective effect of L-NNA in Wistar rats was explained by excessive reduction of NO level essential for ß cell regeneration.

[Antiarrhythmic effect of oligonucleotides accompanied by activation of HSP70 protein in the heart of rats].

UNLABELLED: The mechanisms of the protective effect of oligonucleotides (OGN) during pathological processes are poorlyunderstood. The goal of this work was to study the effect of OGN on arrhythmias induced by myocardial ischemia and reperfusion, and the HSP70 level in the heart. As a source of OGN was used the drug "Derinat" ("Technomedservis", Russia). In male Wistar rats were pre-treated the drug for 7 days (i/m, 7.5 mg/kg).The intensity of the arrhythmias was assessed by ECG during 10 min occlusion of the left coronary artery and subsequent 5 min of reperfusion. Protein HSP70 determined in the left ventricle of the heart by Western-blot analysis. During ischemia, this drug reduced duration of extrasystolia by 13 times and the incidence of ventricular tachycardia by 1.5 times. During reperfusion the drug reduced the incidence of ventricular fibrillation, a more than 2-fold, as compared with the control (respectively 23% vs 56%) and by 5 times its duration (8,4 ± 2,3 48,1 ± sec vs 18 7 sec). "Derinat" increased the HSP70 level in the heart by 65% compared with control. CONCLUSION: These data support the fact that the activation of HSP70 synthesis, induced by OGN is one of the mechanisms that increases the heart resistance to the ischemic and reperfusion damages.

[Effect of the alloxane diabetes on the cardio-vascular system function and lipid peroxidation in rats of different genetic strains].

We have previously shown that the innate increased activity of the NO- system, typical for the August rats, increases vulnerability to alloxane diabetes (ALD). The purpose of this study was to investigate the effect of ALD on the cardiovascular system and lipid peroxidation in rats with different activity of NO-system. The August rats and Wistar rats treated with alloxan (125 mg/kg, s/c, once) were studied 3.5 months after. In August-ALD the double production significantly decreased to a greater extent (by 35%) than in Wistar-ALD (by 17%) compared with the control. As in August-ALD and in Wistar-ALD was observed the similar fall of the relaxation (-dp/dt) of the left ventricle (by 45-49%), but not the contraction rate (+dp/dt). LPO activation in the heart and liver, as well as NO-system (level of nitrates and nitrites in the blood plasma) in August rats were more pronounced than in Wistar rats. The hsp32 level in August rats fell significantly more (by 93% ) than in Wistar rats (by 61%). Pathological changes in the microvasculature of the mesostenium were identical in compared rats. Thus, more pronounced cardiac dysfunction in August-ALD, compared with Wistar-ALD, associated with greater activation of lipid peroxidation and NO-system.

Role of nitric oxide in the pathogenesis of alloxan diabetes.

We studied the effects of N(w)-nitro-L-arginine (L-NNA), a nonselective inhibitor of NO synthases, on the severity of type 1 diabetes mellitus induced by subcutaneous injection of 130 mg/kg alloxan in August rats with high activity of NO system and in Wistar rats. Five days after alloxan injection, hyperglycemia levels after overnight fasting in August and Wistar rats were 27.1±3.7 and 22.0±1.1 mmol/liter, respectively (p<0.03). The mortality over 15 days after alloxan injection in August rats was higher than in Wistar rats (36 and 26%, respectively). L-NNA normalized glucose levels in diabetics of both groups. It completely prevented mortality in August and reduced it to 13% in Wistar rats. Body weight loss and polydipsia after L-NNA injection were also less pronounced in August rats. Plasma nitrite/nitrate concentrations in August rats were 32% higher than in Wistar rats, both in intact and diabetic rats. These data attest to an important role of NO in the pathogenesis of alloxan diabetes.

[The peculiarities of the thymus and cranial mesenteric lymph node structure in the newborn rats after prenatal exposure to ethanol].

The structural peculiarities of the thymus and cranial mesenteric lymph nodes (LN) were examined in 72 neonatal rats born to females, exposed to 15% ethanol solution during pregnancy (n = 34), as well as both during pregnancy and for 1 month preceding it (n = 38). 44 neonatal rats born to intact females, served as a control group. It was shown that the exposure of female rats to ethanol only during pregnancy resulted in more pronounced changes in the mesenteric LN of the offspring than in the thymus. These included the reduction of LN number, cross-sectional area, lymphoid cell relative content, the suppression of mitotic activity, increased reticular cell content and macrophage activity. Pre-gravid ethanol intoxication of females for 1 month in combination with ethanol exposure during pregnancy was shown to have greater effect on the thymus morphogenesis in the offspring. This was manifested by the decrease of its absolute and relative mass, proliferative activity, increase of cell death, appearance of the microcirculatory and dysplastic changes.

[Effect of NO-synthesis blockade on the free-radical processes in rats of different genetic strains with acute alloxan diabetes].

Previously, we have shown that nitric oxide (NO) plays an important role in the pathogenesis of alloxan diabetes (ALD). In this study in August rats, with the congenital increased activity of NO, and in Wistar rats was induced ALD (130 mg/kg, p/c) and 15 days after were examined the effects of the NO-blockade synthesis, induced by administration of Nω-nitro-L-arginine (L-NNA) cour- se on the activity of lipid peroxidation (LP), HIF-1α level, the degree of NO-system activation. The activation of iNOS, HIF-1a expression and 3-nitrotyrosine accumulation in liver were more pronounced in August-ALD rats than in Wistar-ALD rats. The level of TBA-active products in the heart and liver was increased in both diabetic groups only in the first 3 days ofALD and then this indicator of LP sharply was decreased as compared with the control. This effect was pronounced more in August rats. The inhibition of NO overproduction reduced significantly the severity of ALD and prevented the activation of LP, iNOS and HIF-1a. Thus, these data suggest, that NO plays an important role in the pathogenesis of ALD and in the regulation of oxygen homeostasis.

[M1 and M2 macrophage phenotypes functional activity as essential components in innate immune response assessment].

Macrophage capacity to phagocytosis and migration activity are crucial components in innate immune response assessment. Differences in functional responses of two macrophage phenotypes were detected. Phagocytic activity of proinflammatory alveolar M1 phenotype in relation to S. aureus is more expressed than of antinflammatory M2 phenotype. Comparative analysis of migration activity showed alternative dependence of migration index on the type of used chemoattractant.

[Hypoxia, inflammation and phenotypic plasticity of macrophages: the central role of HIF-1 and NFkappaB].

Decrease of oxygen concentration, i.e. hypoxia, in organism tissues and cells is an important pathogenetic component in a large number of diseases. In these cases hypoxia is not only an important component of diseases pathogenesis, but can also influence immune reactions determining the outcome of diseases. Thus, concentration of macrophages in hypoxic areas and their reaction to hypoxia are the key moments in understanding the mechanisms of hypoxia influence on immunity. Macrophages are of the utmost importance in the congenital immune startup and define the vector of development of the adaptive response. In this review we present updated data on influence of hypoxia on macrophages phenotype and their plasticity, and we also analyze genetic trait of macrophages reaction to hypoxia. Molecular mechanisms of immune cells reaction on hypoxia and the role of transcription factors, HIF-1 and NF-kappaB, are analyzed. As a whole, it allowed to describe an important biological phenomenon - hypoxia-regulated control of macrophages phenotypic plasticity, and to define ways of search of new effective approaches to the management of diseases with hypoxic disturbances.

[Resistance to acute hypoxia and changes in the phenotype and phenotypic plasticity of macrophages in mice of different genetic strains].

The aim of study was to investigate the effect of hypoxia on the macrophage phenotype and phenotypic plasticity and to determine the resistance to acute hypoxia in C57/BL mice, which have the pro-inflammatory M1 macrophage phenotype, and in BALB/c mice, which have the anti-inflammatory M2 macrophage phenotype. The following results were obtained. 1) The response of macrophages to acute hypoxia has two successive phases, the immediate, anti-inflammatory phase, and the delayed, pro-inflammatory phase. This response was more distinctly inverted in C57/BL6 M1 macrophages than in BALB/c M2 macrophages; 2) the effect of acute hypoxia on macrophage phenotypic plasticity depends on the genetically predetermined, original macrophage phenotype. In this process, a clear regularity was observed: hypoxia increased the capability of macrophages for changing into the pro-inflammatory M1 phenotype, while their capability for changing into the anti-inflammatory M2 phenotype remained virtually unaffected. 3) BALB/c mice were more resistant to acute hypoxia than C57/BL6 mice. Taken together, these data expand our understanding of mechanisms for pathogenetic effects of hypoxia.

Alternative reprogramming of M1/M2 phenotype of mouse peritoneal macrophages in vitro with interferon-γ and interleukin-4.

An important role in the development of the immune response is played by macrophages that acquire either anti-inflammatory M1 or anti-inflammatory M2 phenotype depending on their microenvironment. The possibility of targeted reprogramming of the initial M2 macrophage phenotype towards M1 phenotype and vice versa using macrophage reprogramming factors IFN-γ and IL-4, respectively, was demonstrated. We showed that macrophages of genetically different mouse strains did not practically differ by their reprogramming capacity. Our findings suggest that macrophage programming not only participates in the triggering of the immune response, but also can ensure plasticity of functional activity during the developing response.

Effect of acute alloxan diabetes on ischemic and reperfusion arrhythmias in rats with different activity of nitric oxide system.

Similar degree of glycemia (28-31 mmol/liter) and similar mortality (37-42%) were revealed in August rats exhibiting enhanced activity of NO system and in Wistar rats 3 weeks after alloxan treatment. Under conditions of myocardial ischemia caused by 10-min coronary artery ligation, the intensity of arrhythmias did not differ from the control in Wistar rats with diabetes mellitus and increased in August rats. Under conditions of reperfusion, diabetes produced an antiarrhythmic effect in Wistar rats and did not affect arrhythmia in August rats. Plasma concentrations of nitrates and nitrites in Wistar and August rats increased by 82 and 143%, respectively, compared to the control. The level of hemoxygenase-1 (hsp32) in the myocardium remained unchanged in Wistar rats and decreased by 26% in August rats. Thus, the absence of antiarrhythmic effect of acute diabetes in August rats is probably related to elevated NO content and reduced antioxidant activity.

SP-D-dependent regulation of NO metabolism in lipopolysaccharide-stimulated peritoneal macrophages.

This work was designed to study the role of surfactant protein D in the regulation of NO synthesis by "non-alveolar" microphages. We evaluated whether the effects of surfactant protein D depend on the phenotype of macrophages. In the absence of surfactant protein D, the LPS-induced iNOS response was shown to decrease in macrophages of native and proinflammatory phenotypes by 30%, and in macrophages of the antiinflammatory phenotype (by 63%). Under the influence of lipopolysaccharide in high doses (500 ng/ml), NO(2)*- production by mouse macrophages without surfactant protein D was reduced in native cells (by 25%), but increased in proinflammatory (by 40%) and antiinflammatory phenotypes (by 12% compared to mouse macrophages with surfactant protein D). Our results suggest that surfactant protein D is involved in the immune response in the whole organism, but not only in the lungs. The effect of surfactant protein D depends on the phenotype of macrophages.

[Soil sorption and transfer from it to plant of the radioactive and stable isotopes of chemical elements: methodology and experimental approach].

The adsorption of pair nuclides 60Co/Co and 65Zn/Zn by solid phase and their availability to plants were studied in soil suspension conditions and in the sod podzolic soil under controlled moisture. The situation when the radionuclide in constant activity is entered to system (surface water, soil) with different heavy metal contamination has been modeled. Was observed that soil contamination with heavy metal Co (Zn) significantly reduce sorption of the radionuclide 60Co (65Zn) by solid phase. As a result, the activity concentration of the 60Co or 65Zn in soil solution and, therefore, their mobility and potential availability to plants increases in 2-4 times with the total metal concentration increasing. The difference between two elements is that high Co concentration increase root uptake of the 60Co, whereas soil contamination with Zn reduce activity of 65Zn in the 14-days barley plants that may reflects diverse plant necessity of two elements and more important role of the isotopic exchange effect in the case of Zn.

[The dynamics of 137Cs content in ontogenesis in barley grown on soil with background and increased contents of heavy metals].

The uptake by barley and the distribution between the vegetative and the generative organs of 137Cs, K and Ca was studied when plants were grown on soddy-podzolic soil with the background content of heavy metals and soil polluted with Cd and Co at concentrations significantly above the maximum permissible concentration (50 i 100 mg/kg accordingly). The reduction was found in 137Cs accumulation and removal with barley in ontogenesis under the action of increased contents of heavy metals in the soil, which was caused by their phytotoxic effect.

[Particularities of adrenergic regulation and the function of cardiovascular system at remote periods after myocardial infarction in rats of different strains].

UNLABELLED: Heart function was studied in the August rats with innate raised sympathetic-adrenal system and in the Wistar rats through the period of 3 month after myocardial infarction. The sizes of the postinfarction scars were similar in the rats under comparison (56-62%) but end-diastolic pressure in Wistar rats and in August rats was 18.7 +/- 2.2 mm Hg and 11.8 +/- 0.7 mm Hg. Under the maximum isometric load induced by the aorta coarctation, the work efficiency of the heart in the August rats was greater than in the Wistar rats. During the postinfarction period, plasma catecholamine (CA) in August rats was higher than in Wistar rats. In the adrenal glands, the CA contents in August rats increased and in Wistar rats decreased. The activity of CA resynthes in the adrenal glands and in the hypothalamus in August rats did not change and in Wistar rats increased. The blood contents of nitrate and nitrite and hemine oxygenase-1 level in the myocardium of August rats were increased in contrast to Wistar rats. THE CONCLUSION: the higher viability of the myocardium in August rats with long existing postinfarction cardiasclerosis is to a considerable extent associated with lowered activation of the sympathetic-adrenal system under more expressing activation of NO-system and antioxidant protection.

[The content in soil and the mobility of artificial radionuclides in the region of the regional radioactive waste storage situation].

The objects of researches are the soil and wild vegetation in the region of the radioactive waste storage situation. In result of monitoring it was recognized 137Cs unlike 90Sr did not spread out of storage territory in spite of trench destruction and migration of radionuclides with surface and ground waters. The forms of 137Cs, 90Sr and natural radionuclide 226Ra in soils and coefficients of 90Sr accumulation for the different kinds of plants growing at the territory of storage and 50-m zone around it were researched. The low specific activities of mobile forms of 90Sr were recognized for samples of soils selected from lowland by the terrace. The considerable differences were found for specific activities of radionuclides for different soil layers. Essential irregularity of soil surface and vegetation contamination at the test points disposed at a short distances from each other also was found. The interpretation of obtained results is presented.