Search

The aim of the study was to investigate the effect of AMP-activated protein kinase activator 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) on the consequences of metabolic syndrome and type 2 diabetes induced by the consumption of a high-fat diet (HFD) in male C57Bl/6 mice. Additionally, the animals from group 6 were administered Methotrexate (MTX) at a dose of 1 mg/kg in parallel with AICAR, which slows down the metabolism of AICAR. The animals were recorded with signs of metabolic syndrome and type 2 diabetes mellitus by recording their body weights, glucose and insulin levels, and the calculating HOMA-IRs. At the end of the study, at the end of the 13th week, during necropsy, the internal organs were assessed, the masses of the organs were recorded, and special attention was paid to visceral fat, assessing its amount and the mass of the fat surrounding epididymis. The biochemical parameters and histology of the internal organs and tissues were assessed. The animals showed signs of metabolic syndrome and type 2 diabetes, namely, weight gain, hyperglycemia, hyperinsulinemia, an increase in the amount and mass of abdominal fat, and metabolic disorders, all expressed in a pathological change in biochemical parameters and pathological changes in internal organs. The AICAR treatment led to a decrease in body weight, a decrease in the amount and mass of abdominal fat, and an improvement in the pathomorphological picture of internal organs. However, some hepatotoxic effects were observed when the animals, on a received standard diet (STD), were treated with AICAR starting from the first day of the study. The additional administration of MTX, an AICAR metabolic inhibitor, did not improve its efficacy. Thus, AICAR has therapeutic potential for the treatment of metabolic syndrome and type 2 diabetes.

The capacities of relatively nontoxic lipopolysaccharide (LPS) from Rhodobacter capsulatus PG and highly potent LPS from Salmonella enterica serovar Typhimurium to evoke proinflammatory cytokine production have been compared in vivo. Intravenous administration of S. enterica LPS at a relatively low dose (1 mg/kg body weight) led to upregulation of TNF-α, IL-6, and IFN-γ production by non-sensitized CD-1 mice. LPS from R. capsulatus PG used at a four-times higher dose than that from S. enterica elicited production of almost the same amount of systemic TNF-α; therefore, the doses of 4 mg/kg LPS from R. capsulatus PG and 1 mg/kg LPS from S. enterica were considered to be approximately equipotential doses with respect to the LPS-dependent TNF-α production by CD-1 mice. Rhodobacter capsulatus PG LPS was a weaker inducer of the production of TNF-α, IL-6, and IFN-γ, as compared to the equipotential dose of S. enterica LPS. Administration of R. capsulatus PG LPS before S. enterica LPS decreased production of IFN-γ, but not of TNF-α and IL-6, induced by S. enterica LPS. Rhodobacter capsulatus PG LPS also suppressed IFN-γ production induced by S. enterica LPS when R. capsulatus PG LPS had been injected as little as 10 min after S. enterica LPS, but to a much lesser extent. Rhodobacter capsulatus PG LPS did not affect TNF-α and IL-6 production induced by the equipotential dose of S. enterica LPS. In order to draw conclusion on the endotoxic activity of particular LPSs, species-specific structure or arrangement of the animal or human immune systems should be considered.

Primary memory impairments associated with increased level of amyloid-beta (Аβ) in the\ud brain have been shown to be linked, partially, with early pathological changes in the\ud entorhinal cortex (EC) which spread on the whole limbic system. While the hippocampus is\ud known to play a key role in learning and memory mechanisms, it is as yet unclear how its\ud structures are involved in the EC pathology. In this study, changes in memory and neuronal\ud morphology in male Wistar rats intrahippocampally injected with Аβ25–35 were correlated on\ud days 14 and 45 after the injection to reveal specific cognitive - structural associations. The\ud main focus was on the dentate gyrus (DG) and hippocampal areas of CA1 and CA3 because\ud of their involvement in afferent flows from EC to the hippocampus through tri-synaptic (EC \ud DG CA3 CA1) and/or mono-synaptic (EC CA1) pathways. Evident memory\ud impairments were observed at both time points after Аβ25–35 injection. However, on day 14,\ud populations of morphological intact neurons were decreased in CA3 and, drastically, in CA1,\ud and the DG supramedial bundle was significantly damaged. On day 45, this bundle largely\ud and СА1 neurons partially recovered, whereas CA3 neurons remained damaged. We\ud suggest that Аβ25–35 primarily affects the tri-synaptic pathway, destroying the granular cells in\ud the DG supramedial area and neurons in CA3 and, through the Schaffer collaterals, in CA1.\ud Intrahippocampal pretreatment with hydrated fullerene С60 allows the neurons and their\ud connections to survive the amyloidosis, thus supporting the memory mechanisms.

АРНС1-3 peptides, modulators of TRPV1 receptors, have been administered to SD rats to study their influence on the animal hemostatic system, heart rate, and blood pressure. None of АЗРС1-3 polypeptides have any effect on the hemostatic system. Both АРНС1 and АРНС2 polypeptides increased significantly the heart rate, but they did not affect blood pressure, which was probably caused by an ability of these polypeptides to modify animal thermoregulation.

Directions of migration of mononuclear bone marrow cells after intracoronary transventricular injection procedure developed by us were experimentally studied. After nonselective injection of cells into the right and left coronary arteries in rats, the labeled cells were detected only in the damaged zone of the myocardium. Localization of transplanted mononuclears in the scar attests to their homing into the damaged zone. Numerous cells were found in the red pulp of the spleen and solitary cells were detected in the liver and lungs. In the heart, the labeled transplanted cells were detected only in the scar zone at all terms of the study; they were not incorporated into the vascular walls, but were surrounded by thick bundles of collagen fibers and probably underwent differentiation into fibroblasts. No data on possible differentiation of the transplanted cells into vascular cells or cardiomyocytes were obtained.

Study of tumorigenic activity of cultured human chondroblasts intended for autologous transplantations showed that subcutaneous injection of human chondroblast suspension in a dose of 10(7)cells/0.2 ml did not cause the development of tumors in C.B-17 SCID immunodeficient mice over 12 weeks. Subcutaneous formations of compact cartilaginous consistency persisted at the site of chondroblast transplantation in all animals; these formations gradually shrank. Subcutaneous injection of tumor cell suspension (A204 human embryonic sarcoma) to C.B-17 SCID mice under the same conditions caused 100% development of tumors (poorly differentiated sarcomas) by day 14.

Bilateral occlusion of carotid arteries in awake hypertensive rats (SHR-SP) was used as a model of global brain ischemia (duration of occlusion — until appearance of seizures). In normotensive rats (WKY), no seizures developed over 60 min. We revealed swelling of mitochondria in dendrites of hippocampal CA1 pyramidal cells, which was more pronounced in SHP-SP than in WKY rats. Blood pressure and heart rate in SHR-SP rats increased starting from the first minutes of occlusion, while in WKY rats these parameters remained unchanged. We proved that bilateral occlusion of the carotid arteries in awake SHR-SP rats can be used as an adequate model of global cerebral ischemia.

Myelin oligodendrocyte glycoprotein (MOG) is one of the major autoantigens in multiple sclerosis (MS), therefore selective depletion of autoreactive lymphocytes exposing MOG-specific B cell receptors (BCRs) would be beneficial in terms of MS treatment.Using E. coli we generated an efficient protocol for the purification of the recombinant immunotoxin DT-MOG composed of the extracellular Ig-like domain of MOG fused in frame with the catalytic and translocation subunits of diphtheria toxin (DT, Corynebacterium diphtheriae) under native conditions with a final yield of 1.5 mg per liter of culture medium. Recombinant DT-MOG was recognized in vitro by MOG-reactive antibodies and has catalytic activity comparable with wild-type DT.Enhanced pharmacokinetics (mean residence time in the bloodstream of 61 min) and minimized diminished nonspecific toxicity (LD50 = 1.76 mg/kg) of the DT-MOG makes it a potential candidate for the immunotherapy of MS.

Weak neurotoxins belong to the superfamily of three-finger toxins from snake venoms. In general, weak toxins have a low toxicity and, contrary to other three-finger toxins, their molecular targets are not well characterized: in vitro tests indicate that these may be nicotinic acetylcholine receptors. Here, we report the influence of intraperitoneal and intravenous injections of weak neurotoxin from Naja kaouthia venom on mouse behaviour. Dose-dependent suppression of orientation-exploration and locomotion activities as well as relatively weak neurotropic effects of weak neurotoxin were observed. The myorelaxation effect suggests a weak antagonistic activity against muscle-type nicotinic acetylcholine receptors. Neurotoxic effects of weak neurotoxin were related to its influence on peripheral nervous system. The symptomatology of the intoxication was shown to resemble that of muscarinic agonists. Our data suggest that, in addition to interaction with nicotinic acetylcholine receptors observed earlier in vitro, weak neurotoxin interacts in vivo with some other molecular targets. The results of behavioural experiments are in accord with the pharmacological profile of weak neurotoxin effects on haemodynamics in mice and rat indicating the involvement of both nicotinic and muscarinic acetylcholine receptors.

We analyzed changes in angiotensin-converting enzyme activity in the aorta of hypertensive SHR rats against the background of age-related BP increase (from week 7 to 14) and the effect of dihydroquercetin on BP rise and angiotensin-converting enzyme activity. Normotensive WKY rats of the same age were used as the control. BP and activity of angiotensin-converting enzyme in the aorta of SHR rats increased with age. Dihydroquercetin in doses of 100 and 300 μg/kg per day had no effect on the increase of these parameters; dihydroquercetin administered to 14-week-old WKY rats in a dose of 300 μg/kg reduced activity of the angiotensin-converting enzyme. Thus, the early (7-14 weeks) increase in BP and angiotensin-converting enzyme activity in the aorta of SHR rats was not modified by flavonoids (dihydroquercetin) in contrast to other rat strains and humans, which is indicative of specificity of hypertension mechanism in SHR rats.

The relationship between hydroxyl radical (OH*) generation in the zone of ischemia/reperfusion and the size of infarction formed was investigated in 18-22-week-old anaesthetized male SHRSP and Wistar rats using a myocardial microdialysis technique. The marker of OH* generation, 2,3-dihydroxybenzoic acid (2,3-DHBA), was analyzed in dialyzates by high performance liquid chromatography with electrochemical detection. Myocardial ischemia was induced by ligation of the descending branch of the left main coronary artery for 30 min. The mean value of basal 2,3-DHBA level in the dialyzate samples from SHRSP (243 +/- 21 pg for 30 min) was significantly higher than that from Wistar rats (91 +/- 4 pg for 30 min, p0.0002); it positively correlated with left ventricular hypertrophy (r = 0.806; p0.05). During reperfusion total 2,3-DHBA output was 1.8-fold higher in SHRSP than in Wistar rats (659 +/- 60 pg versus 364 +/- 66 pg for 60 min, respectively, p0.0002). At the same time, 2,3-DHBA increase above the basal level was the same in Wistar and SHRSP rats (181 +/- 25 and 172 +/- 36 pg for 60 min, respectively). The infarct size in SHRSP (45.4 +/- 4.3%) was significantly higher (p0.05) than in Wistar rats (32.8 +/- 3.3%). There was a significant positive correlation between basal level of 2,3-DHBA and total reperfusion 2,3-DHBA content in SHRSP (r = 0.752; p0.05). Thus, data obtained clearly indicate that the hypertrophied myocardium of SHRSP was less tolerant to ischemia/reperfusion than that of Wistar rats due to chronically increased OH* production and enhanced total OH* output during reperfusion. Greater myocardial damage in SHRSP than in Wistar rats following the equal increase in OH* production above the basal level suggests the existence of deficit of the antioxidant defense in the hypertrophied myocardium.

Arrythmogenic effects of endothelin-1 were studied in NMRI mice under conditions of NO-synthase blockade with N omega-nitro-L-arginine methyl ester. Intravenous injection of endothelin-1 increased heart rate variability in awake mice. NO-synthase blockade potentiated the arrythmogenic effects of endothelin-1. In narcotized animals the arrythmogenic effect of endothelin-1 was not observed and was considerably weakened under conditions of NO-synthase blockade. Arrhythmia was paralleled by atrioventricular block and lengthening of the ST segment.

Local injection of 4 nmol moxonidine (unilaterally) into the rostroventrolateral medulla of spontaneously hypertensive rats (SHR-SP) decreased mean blood pressure and heart rate by 24±3 and 3±4%, respectively. Pretreatment with the I1/α2-receptor antagonist efaroxan abolished the moxonidine-induced decrease in mean blood pressure, but had no effect on heart rate. Yohimbine blocked hypotension, delayed bradycardia (8 nmol), or completely inhibited the effects of moxonidine (16 nmol). Our results indicate that both I1-imidazoline receptors and α2-adrenoceptors of the rostroventrolateral medulla are involved in the realization of moxonidine-induced changes.

62 Zervamicins isolated from the fungus Emericellopsis salmosynnemata belong to the peptaibols family. They consist of 15 amino acid residues and C-terminal moiety of the amino alcohol phenylalaninol. Primary structures of zervamicins IIA and IIB (Zrv-IIA and Zrv-IIB) differ in only one amino acid residue at position 4 ( α -aminoisobutyric acid in Zrv-IIA and D -isovaline in Zrv-IIB) [1, 2]. It was shown that an intraperitoneal injection of Zrv-IIA and Zrv-IIB to male Wister rats in an open-field test caused a decrease in the locomotor and exploratory activity of animals [3]. A study of neurotropic activity of male CD-1 mice in holeboard, elevated plus maze, and forced-swim tests revealed differences in the efficiency of these peptaibols [4]. To study the neurotropic effect of zervamicins in greater detail, we investigated their analgetic activity in the hot-plate test and assessed their effect on body temperature of laboratory animals. This study was performed with 6- to 8-week-old male CD-1 mice. The animals were housed under the standard conditions (light/dark cycle, 12 : 12 h; room temperature, 18‐26 ° C; humidity, 30‐70%) and received water and food ad libitum. All manipulations with animals were performed in conformity with the protocol approved by the Committee on Animal Research and Ethics of the Institute of Bioorganic

We compared the efficiency of autologous mononuclear cells and multipotent stromal cells of the bone marrow after their non-selective intracoronary transplantation on day 30 after acute coronary infarction in rats. Improvement of hemodynamic parameters of myocardial contractility (rates of left ventricular pressure rise and drop) in comparison with the initial values and deceleration of postinfarction prolongation of QRS and QT intervals were observed in rats of the experimental group in contrast to controls in 4 weeks after transplantation. These functional changes were more intensive after transplantation of multipotent stromal cells and were accompanied by more pronounced morphological signs of reverse myocardial remodeling: thickening of the scarred left ventricular wall, shrinkage of the scar, and decrease in left ventricular dilatation index.

Safety and efficiency of intracoronary transventricular transplantation of autologous mononuclear bone marrow cells in rats with postinfarction cardiosclerosis were studied. The cells migrated to the damaged area and were detected only in the cicatricial tissue; they have fibroblast-like phenotype and some of them were stained with Fapα (marker of reactive fibroblasts). More active proliferation of non-muscular cells and formation and maturation of collagen fibers in the cicatricial tissue were observed after transplantation of mononuclear cells. This led to thickening of the cicatricial wall, but the size of the scar and index of dilatation of the left ventricle remained unchanged. The number and volume density of newly formed blood vessels in the damaged area increased after transplantation, but no labeled cells were seen in the vascular walls. It can be hypothesized that stimulation of neoangiogenesis is mediated by paracrine mechanisms, which also explains improvement of global contractility of the left ventricle (increased contractility index in functional tests). Thus, transplantation of mononuclear bone marrow cells leads to thickening and strengthening of the cicatricial wall, stimulates angiogenesis, and improves global myocardial contractility. However, no morphological signs of reverse remodeling of the left-ventricular myocardium were revealed.

Single intravenous injection of antidepressant tetrindol (1 and 10 mg/kg), a reversible monoamine oxidase A inhibitor, dose-dependently decreased heart rate and mean arterial pressure (in a concentration of 10 mg/kg) in alert NMRI mice and Sprague-Dawley rats. Nitric oxide synthase blockade with L-NAME attenuated tetrindol-induced bradycardia in rats and completely abolished this effect in mice.

The influence of recombinant human tumor necrosis factor-alpha (TNF-alpha) and calcium ionophore A23187 on luminol- and lucigenin-dependent chemiluminescence capacity (CL) of human polymorphonuclear leukocytes (PMN) has been studied. The CL response of TNF-alpha treated PMN is amplified by lucigenin, but not luminol. TNF-alpha and A23287 synergistically induced both the luminol- and lucigenin-dependent early CL response. The combination of A23187 and activator of protein kinase C--phorbol (myristoyl-13-acetyl)--also provoked early CL response. While the combination of TNF-alpha and A23187 decreased late CL response compared to A23187 alone. The obtained results suggests that synergistic CL response of PMN induced by TNF-alpha and A23187 is connected with activation of protein kinase by TNF-alpha.

Blood concentration of soluble Fas antigen is higher in patients with benign and malignant tumors in comparison with healthy subjects, which probably suggests its involvement into tumorigenesis.

Excessive UV radiation suppresses processes important for normal functioning of tissues [1, 2]. Therefore, a topical problem is studying the factors which protect cells from the negative effects of UV radiation. One of such factors may be illumination with light of orange-red range of the spectrum [2‐4]. The primary skin-muscular fibroblasts were isolated from 15-day-old embryos of SHR rats with the SPF status (the nursery of Shemyakin‐Ovchinnikov Institute of Bioorganic Chemistry (Pushchino Branch), Russian Academy of Sciences, Pushchino). The suspension of fibroblasts was placed in tissue culture flasks impermeable to UV-A and orange‐red light (ORL). After one day of incubation, the medium with unadhered cells was removed and the adhered fibroblasts were cultured untill formation of a monolayer in DMEM (ICN) supplemented with glutamine, HEPES, and fetal calf serum. The cells were kept in an incubator at 37°C in a 5% CO 2 atmosphere. The fibroblasts of the 4th to 8th passages were used in the experiments. The adhered cells were detached with the use of a mixture of trypsin and Versen (Pan Eko), counted, and placed in flasks for illumination with ORL (0.9‐3.6 J/cm 2 ) or UV-A (0.27‐1.08 J/cm 2 ) or their combinations. A matrix with light-emitting Luxeon Star diodes (Lumileds) with λ m = 625 nm and a light flux intensity of 5.5 mW/cm 2 was used as source of ORL. An MD-108 irradiator (Germany) with λ M = 365 nm and a light flux intensity of 2.5 mW/cm 2 was used as a UV-A source. The suspension of fibroblasts was distributed with the use of pipette in 96-well plates for analysis of the proliferation rate. Each well with culture medium contained 10 4 cells. The fibroblasts were stained with thiazolyl blue 48 and 72 h after illumination. The cells were additionally incubated for 1 h and, then, the medium in the wells was replaced with dimethylsulfoxide. The optical density of the cells was determined with the use of a Spectra Count spectrophotometer (Packard, Germany). Analysis of the fibroblast proliferation 48 h after illumination showed that ORL had a stimulatory effect at a dose of 0.9 J/cm 2 (Fig. 1), which is in agreement

We studied the effects of blockade of nicotinic receptors in sympathetic and parasympathetic ganglia (hexamethonium), muscarinic receptors (atropine), and beta1-adrenoceptors (atenolol) on arrhythmogenic activity of endothelin-1 during inhibition of nitric oxide synthesis with Nomega-nitro-L-arginine in NMRI mice. Atropine reduced, while hexamethonium completely abolished the arrhythmogenic effect of endothelin-1 during nitric oxide synthase inhibition. Atenolol potentiated arrhythmogenic activity of Nomega-nitro-L-arginine, but endothelin-1 had no effect on the incidence of arrhythmias under these conditions.

Systemic hemodynamic parameters in 5-month-old and 10-month-old normotensive Wistar-Kyoto and spontaneously hypertensive (SHR) conscious rats were studied with microsphere technique. Cardiac index was similar in both strains of rats and was not significantly different between 5 and 10 months. Left ventricle catheter implantation through the right common carotid artery evoked the development of heart failure in 10-month-old SHR (in the first day after operation). This model can be used for screening of new drugs for heart failure treatment.