Both peripheral neuropathy and depression can be viewed as neurodegeneration's consequences of diabetes, at least in part coexisting with or resulting from sodium-calcium dysbalance. This study aims to assess the therapeutic potential of the orally applied reverse-mode inhibitor of the sodium-calcium exchanger (NCX) KB-R7943 in the streptozotocin (STZ) diabetes model in rats. A pilot pharmacokinetic (PK) study with high-performance liquid chromatography with high-resolution tandem mass spectrometric detection revealed higher drug exposure (AUC), lower volume of distribution (Vd) and clearance (Cl), and faster decline of the plasma concentration (lambda) in rats with diabetes vs. controls. Brain and heart accumulation and urinary excretion of the unmetabolized KB-R7943 at least 24 h were also demonstrated in all rats. However, heart and hippocampus KB-R7943 penetration (AUC(tissue)/AUC(plasma)) was higher in controls vs. diabetic rats. The development of thermal, mechanical, and chemical-induced allodynia was assessed with the Cold plate test (CPT), Randall-Stiletto (R-S) test, and 0.5% formalin test (FT). Amitriptyline 10 mg/kg, KB-R7943 5 mg/kg, or 10 mg/kg p.o once daily was applied from the 28th to the 49th day. The body weight, coat status, CPT, R-S, and FT were evaluated on days (5), 0, and 42. On day 41, a forced swim test and 24-h spontaneous physical activities were assessed. The chronic treatment effects were calculated as % of the maximum. A dose-depended amelioration of neuropathic and depression-like effects was demonstrated. The oral application of KB-R7943 for potentially treating neurodegenerative consequences of diabetes merits further studies. The brain, heart, and kidneys are essential contributors to the PKs of this drug, and their safety involvement needs to be further characterized.

One of the complications of diabetes mellitus (DM) is diabetic cardiomyopathy (DCM), whose molecular mechanisms of pathogenesis have not been fully studied. Previously, the involvement of Na+/K+-ATPase and components of the Ca2+ transport system in cardiomyocytes in the development of DCM was shown. The aim of the work was to study the expression and activity of Na+/K+-ATPase and Ca2+-ATPase (SERCA2) in the myocardium of male Wistar rats in a model of streptozotocin (STZ)-induced prediabetes and overt type 1 diabetes (T1DM). STZ was administered at once i.p. in doses of 30–35 mg/kg. Rats with glucose levels above 11 mM were considered diabetic (STZ-D1 group), and those with moderate hyperglycemia were considered prediabetic (STZ-preD1 group). The activity of Na+/K+-ATPase and Ca2+-ATPase was determined (by the rate of release of inorganic phosphate, Pi), and the expression of the genes α1- and α2-isoforms of Na+/K+-ATPase, SERCA2, and Kir6.1, Kv7.1, and Kv2.1 potassium channels was also determined. In the control (C) group, the activity of ouabain (1 mM) -sensitive Mg2+-dependent ATPase was 6.03 ± 0.6 mmol Pi/g/h. In the STZ-D1 and STZ-preD1 groups, Na+/K+-ATPase activity did not differ from group C. The level of gene expression of α1- and α2- subunits of Na+/K+-ATPase in the STZ-D1 group decreased by more than 45 STZ-preD1 group increased by 64 and 81 sensitivity of expression to insulinopenia. The activity of Ca2+-ATPase and the expression of the SERCA2 gene did not differ between the groups, which might be because the 4-week period after STZ administration is not sufficient for the development of Ca2+-ATPase deficiency in the rat heart. The level of expression of the genes of the potassium channel subtypes Kv2.1, Kir6.1, and Kv7.1 increased in the STZ-preD1 group, which may indicate a potential contribution of the studied potassium channel subtypes to the adaptation mechanism to moderate hyperglycemia.

Мастер-класс ВЫБОР СТРАТЕГИИ НАЧАЛЬНОЙ ШКОЛЫ В УСЛОВИЯХ ВЫСОКОЙ НЕВРОТИЗАЦИИ ГОРОДСКИХ ДЕТЕЙ Частная школа Кукувайя, Москва, Россия Руководители -Мудрова Евгения Борисовна, Святловская Евгения Александровна (в рамках секции 3 "Мышление и сознание") Королёва А.В.ВЫБОР СТРАТЕГИИ НАЧАЛЬНОЙ ШКОЛЫ В УСЛОВИЯХ ВЫСОКОЙ НЕВРОТИЗАЦИИ ГОРОДСКИХ ДЕТЕЙ ВЗГЛЯД ОСТЕОПАТА.КОГДА НАБЛЮДЕНИЕ И ПОМОЩЬ ВРАЧА-ОСТЕОПАТА СТАНОВИТСЯ НЕОБХОДИМОЙ ЧАСТЬЮ УЧЕБНОГО ПРОЦЕССА.Korolyeva A.V. WHAT STRATEGY TO CHOOSE FOR PRIMARY SCHOOL

Cardiovascular pathology is the main cause of morbidity among patients with diabetes mellitus. The development of a specific therapy aimed at either blunting the protein signals involved in pathological cardiomyocyte hypertrophy or upregulating the expression of cardioprotective pathways can support new strategies for treating diabetes-induced cardiac dysfunctions. The aim of the work was to study the impact of intranasal insulin administration (IIA) on the expression of genes encoding insulin-dependent signaling proteins and components of the Ca 2+ -transporting system, as well as on the activity of Na + /K + -ATPase in cardiomyocytes on the model of experimental type 1 diabetes mellitus (DM1) in rats. It was shown that IIA eliminates the uncoupling of molecular mechanisms involved in electromechanical coupling in rat cardiomyocytes that occurs under the conditions of mild DM1. This allowed us to recommend IIA as a therapeutic approach to the prevention and treatment of structural and functional myocardial disorders caused by diabetes.

The role of small conductance (SK) Ca2+-dependentpotassium channels in pathogenesis of diabetic cardiomyopathy remainsuncertain. In our studies in the rat model of streptozotocin-inducedtype 1 diabetess mellitus (STZ-DM1) a significant increase abovecontrol in the prevalence of extracellular action potentials (eAP)recorded from isolated heart left ventricles and terminating witha prominent phase of after-hyperpolarization was observed. In experimentswith local delivery to the site of recording of several tested potasssiumchannel blockers suppression of this phase of eAP after hyperpolarizationwas achieved only with application of apamin, the selective SK channelinhibitor. These data suggest that eAP afterhyperpolarization phaseis associated with activation of SK channels and that activity and/orexpression of these channels is increased in epicardial cardiomyocytesof left ventricles of STZ-DM1 rat hearts.

We analyzed the effects of intranasal administration of insulin (0.48 U/rat) and gangliosides (6 mg/kg) on spatial memory in rats with the neonatal model of the type 2 diabetes mellitus. The development of diabetes was verified by the glucose tolerance test. Insulin and gangliosides improved training and reversal training in diabetic rats in a modified version of Morris water maze test and reduced the time of finding the hidden platform. High effectiveness of intranasal administration of gangliosides to animals for the normalization of cognitive functions was shown for the first time. The effects of insulin and gangliosides were similar during training, but during reversal training, gangliosides were more effective. At the same time, intranasally administered insulin, unlike gangliosides, partially normalized glucose tolerance in rats with type 2 diabetes mellitus.

Bariatric surgery is widely used to correct the metabolic dysfunctions in type 2 diabetes mellitus (T2DM), but the mechanisms of its action are not fully understood. The aim of the work was to study the effect of Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) on the metabolic and hormonal parameters and on the expression of the hypothalamic genes encoding appetite-regulating factors and the components of signaling systems controlling an energy metabolism in male rats with T2DM without obesity. The T2DM was induced by a 20-week high-fat diet and treatment of rats with 20 mg/kg of streptozotocin (STZ) at the 12th week of the experiment. The operations were performed 3 weeks after STZ treatment. The glucose sensitivity and the hormonal parameters were evaluated at the 19th week, and the hypothalamic tissues were taken at the 20th week to evaluate the gene expression. In rats with T2DM, both operations reduced the food intake, decreased the postprandial glucose levels, normalized the leptin levels, and lowered the plasma ghrelin levels in T2DM. The SG, which, in comparison with RYGB, had a lesser effect on the glucose homeostasis and the ghrelin level, reduced the food intake more effectively and, unlike RYGB, restored the glucagon-like peptide-1 (GLP-1) level decreased in T2DM. The RYGB led to a decrease in the expression of orexigenic genes, encoding agouti-like peptide and ghrelin receptor, increased in T2DM, and to an increase in the expression of anorexigenic genes, encoding the MC3- and MC4-melanocortin, the 5-HT2C-serotonin and leptin receptors and pro-opiomelanocortin. The largest contribution to the effects of SG is made by a significant increase in the hypothalamic expression of the GLP-1 receptor gene, associated with an increase in the plasma GLP-1 level. Thus, the RYGB and SG can be effective to correct the metabolic and functional dysfunctions in non-obese T2DM, and the restoration of the balance between the hypothalamic orexigenic and anorexigenic pathways makes a significant contribution to these effects.

Left ventricles (LV) of isolated hearts of the control rats (n = 7) and rats injected with streptozotocin (STZ; n = 21) were studied on the four-week post-injection term using 5-µm tip (O.D.) glass extracellular microelectrodes. STZ-rats that maintained hyperglycemia by the time of the study (random glucose > 11 mM; n = 3) were designated as diabetic animals (diabetes mellitus group; STZ-DM). Remaining STZ-rats (n = 18) were designated as normoglycemic rats (STZ-NG group). In control and in STZ-rat hearts two main types of sinus rhythm action potentials (AP) of epicardial ventricular myocytes could be recorded: signals characterized by a single (AP1) or double negative peaks (AP2). Respective time parameters of AP1 (rise time, and 50% and 90% decay times (T50 and T90) not differed between studied groups of rats. However, T50 of AP2 of LV myocytes of STZ-NG and STZ-DM rats were statistically significantly longer than T50 of AP2 recorded in control rat hearts. Furthermore, in 28% of STZ-NG and in 67% of STZ-DM rat hearts additional type of AP (AP3) featuring a complex, multi-peak negative phase and prominent positive phase of after-hyperpolarization were recorded. Appearance of AP3 was associated with a proportional decrease in the relative frequency of AP2 recordings (from 80-85% to 55-60% of all recordings). Frequency of AP1 recordings remained stable, 15-20% in all experiments in all groups of rats. Tentatively, observed in this study modulation in electrical activity of ventricular myocytes of STZ-rat hearts results from structure-functional changes in organization of the T-system of these myocytes. Regardless of validity of this suggestion, it is important that changes in electrogenesis of cardiomyocytes develop fast (1 month) not only in STZ-DM rats, but also in hearts of STZ-rats with normal or moderately increased blood glucose levels, which may be considered as the state equivalent to the state of early prediabetes.

Disorganization of the T-system of cardiomyocytes is considered an early and critical step in the development of Diabetic Cardiomyopathy (DCM). To test this suggestion, male Wistar rats were injected with streptozotocin (STZ, 30 or 45 mg/kg) and studied one month later. STZ-rats that developed and maintained hyperglycemia (random blood glucose > 11 mM) were designated as hyperglycemic (STZ-HG) rats, while the remaining STZ-rats – as normoglycemic (STZ-NG) animals. The structural integrity of the T-system was investigated using an analysis of confocal images of the left ventricle (LV) sub-epicardium of isolated hearts, stained with the Di-8-ANEPPS. In control, T-system was organized into regular networks of t-tubules aligned with Z-discs of cardiomyocyte’s sarcomeres. Accordingly, the frequency distributions of intervals between neighboring t-tubules (INT, measured along the major cell axis) peaked at a 2 µm value with not more than 21% of INT (per cell) exceeding the 3 µm cut-off. Only 4±3% of the control cardiomyocytes (274 cells, 4 rats) could be considered as deficient, according to this parameter (>21% occurrence of long INT). Compared to control, in the hearts of STZ-NG and STZ-HG rats, the fractions of such deficient cardiomyocytes were statistically significantly higher: 48±13% (STZ-NG, 8 rats, 573 cells) and 76±8% (STZ-HG, 4 rats, 247 cells). Thus, structural changes in the T-system of the rat heart LV cardiomyocytes develop early during chronic hyperglycemia (overt diabetes) as well as during near-normoglycemic stages of diabetes (prediabetes). The relevance of these changes to the development of DCM in subjects with prediabetes remains to be studied.

Cardiac disruption and development of a diabetic cardiomyopathy (DCM) are a direct consequence of diabetes. In work activity Na/K-ATPase in a myocardium of rats with different extent of diabetic impairment was studied. Suppression of activity of Na/K-ATPase in the cardiomyocytes the left ventricle of rats was revealed at strongly developed diabetes, but not at a prediabetes stage. It was concluded, that development of DCM breaks transport processes in a membrane of rats cardiomyocytes, and the expressiveness of observed changes depends on diabetes degree.

Background. Metabolic syndrome (MS) is characterized by a number of pathogenetic factors that adversely affect the function of the central nervous system (CNS). The study of early stages of ultrastructural damages in the CNS in the conditions of MS is important for compensation and prevention of pathological states leading to the brain hypoxia and cognitive disorders. Objective. The aim was to investigate the morphological characteristics of the brain tissue and the cerebral capillaries in neocortex (the I-VI layers) sensorimotor region of rats with MS induced by a long-term (15 weeks) high-carbohydrate/high-fat (HC/HF) diet. Design and methods. The neocortex ultrastructure was investigated using an electron microscopy. Results. The moderate destructive changes in the components of the neurovascular units of the sensorimotor region of the cerebral cortex were detected in MS rats. Regardless of the functional response of brain capillaries (vasodilatation / vasoconstriction) to systemic insulin resistance and hyperglycemia, the signs of blood-brain barrier (BBB) dysfunctions were detected in MS-rats, such as an increase in the thickness and the impaired integrity of the basement membrane, endothelial microclasmosis, edema, and the estruction of perivascular glia. The destructive changes in cerebral capillaries were combined with neuro-vasal contacts increased 2,3 times, the proportion of apoptotic neurons increased 5 times and the proportion of normochromic neurons accurately reduced by 13 %. Conclusion. In neocortex sensorimotor region of rats with MS induced by the HC/HF diet, the moderate dysfunction of the BBB and the reactive changes in neurons and neuro-vasal contacts were shown, and the cause of which may be hyperglycemia, dyslipidemia, and systemic insulin resistance typical for MS.

The metabolic syndrome (MS) is characterized by chronic mild inflammation that is a consequence of complex interaction between the genetic and environmental factors. The review presents the current view on the role of inflammation and oxidative stress in the development of MS and pathology associated with it. The contribution of adipokines and adipocytokines, such as tumor necrosis factor-б (TNF-б), interleukin-6 (IL-6), leptin, adiponectin and plasminogen activator inhibitor-1 (PAI-1), in the development of inflammation, obesity and insulin resistance is discussed. The molecular mechanisms of formation of oxidative stress in MS are considered. The review provides information on the redox-sensitive transcription factors such as FoxO, NF-кB and AP-1, and also on the Keap1/Nrf2/ARE system which play an important role in the integration of the intracellular signal systems participating in the inflammatory processes and responsible for the decrease in insulin sensitivity. A conclusion was made on the functional interrelation between the oxidative stress, inflammation, obesity and MS.

The pro-opiomelanocortin (POMC)-expressing neurons of the hypothalamic arcuate nucleus (ARC) are involved in the control of food intake and metabolic processes. It is assumed that, in addition to leptin, the activity of these neurons is regulated by serotonin and dopamine, but only subtype 2C serotonin receptors (5-HT2CR) was identified earlier on the POMC-neurons. The aim of this work was a comparative study of the localization and number of leptin receptors (LepR), types 1 and 2 dopamine receptors (D1R, D2R), 5-HT1BR and 5-HT2CR on the POMC-neurons and the expression of the genes encoding them in the ARC of the normal and diet-induced obese (DIO) rodents and the agouti mice (A y /a) with the melanocortin obesity. As shown by immunohistochemistry (IHC), all the studied receptors were located on the POMC-immunopositive neurons, and their IHC-content was in agreement with the expression of their genes. In DIO rats the number of D1R and D2R in the POMC-neurons and their expression in the ARC were reduced. In DIO mice the number of D1R and D2R did not change, while the number of LepR and 5-HT2CR was increased, although to a small extent. In the POMC-neurons of agouti mice the number of LepR, D2R, 5-HT1BR and 5-HT2CR was increased, and the D1R number was reduced. Thus, our data demonstrates for the first time the localization of different types of the serotonin and dopamine receptors on the POMC-neurons and a specific pattern of the changes of their number and expression in the DIO and melanocortin obesity.

Metformin (MF), a first-line drug in the treatment of diabetes mellitus, has been used in recent years to treat obesity. Its therapeutic effect is due not only to the influence on the peripheral tissues but also on the hypothalamus, which controls food behavior and energy metabolism. The goal was to study the effect of MF therapy (200 mg/kg/day, 8 weeks) in rats with obesity caused by a high-carbohydrate and high-fat diet on metabolic and hormonal parameters and the functional state of the hypothalamic signaling systems. MF treatment of obese rats (the group ObM) normalized food behavior; reduced the body weight and fat weight and the glucose, insulin, and leptin levels; increased sensitivity to glucose and insulin; improved the lipid metabolism; and restored Ser473 phosphorylation of Akt kinase in the liver. In the hypothalamus, the stimulating effects of agonists of type-4 melanocortin receptor and type-1 dopamine receptor on adenylyl cyclase (AC) were partially restored, the inhibitory effect on AC of agonists of subtype-1B serotonin receptor (5-HT1BR) increased (which was associated with an increase in Htr1b gene expression), and the stimulating effect of the 5-HT6R agonist EMD-386088 normalized. At the same time, the differences in the activity of the leptin and insulin systems and the ratio of anorexigenic and orexigenic factors in the hypothalamus of the rat groups Ob and ObM were insignificant. Thus, MF treatment changes the functional activity of the hypothalamic melanocortin, dopamine, and serotonin systems in obese rats, which is one way to decrease their food intake and to restore the metabolic parameters and insulin sensitivity.

The hypothalamus controls food behavior, and the abnormalities in this regulation induce obesity. This is largely due to the changes in the balance of the hypothalamic factors, such as ore-xigenic factors, including orexin (OR), agouti-like peptide (AgRP) and neuropeptide Y (NPY), and anorexigenic factors including the melanocortin peptides generated from pro-opiomelanocortin (POMC). The data on the expression and the ratio of these factors in obesity induced by the high-calorie diet are few and contradictory. The aim was to study the expression of POMC, OR of the A-type (OR-A), AgRP and NPY in the hypothalamic structures of male rats with cafeteria diet-induced obesity as compared to control animals. Starting the 26-day-old age, the rats consumed a cafeteria diet for 12 weeks, which leads to obesity, insulin resistance, the changes in the carbohydrate and lipid metabolism, and hyperleptinemia. In the perifornical area of the hypothalamus of obese rats, a significant decrease in the number of OR-A and the mRNA expression for the gene encoding pre-proorexin, the OR-A precursor, was shown. In the hypothalamic arcuate nuclei of obese rats, the expression of the gene for AgRP, the antagonist of type 4 melanocortin receptor, was decreased, the expression of the gene for POMC was increased, and the expression of the gene for NPY changed to a small extent. Thus, in different areas of the hypothalamus of rats with cafeteria diet-induced obesity, the compensatory processes are triggered to increase anorexigenic effects and suppress orexigenic effects, which should weaken hyperphagia and prevent the negative metabolic and hormonal changes caused by excessive caloric intake