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OBJECTIVES Aims of this study were to investigate the anti-arrhythmic and cardio-protective effect of atorvastatin and of a new pyridoindole derivative (SMe1EC2) on isolated and perfused hearts while following the Langendorff principles. BACKGROUND Metabolic syndrome is a widely distributed condition progressing to cardiovascular disease. Many of the metabolic syndrome patients take (HMG)-co-enzyme A (CoA) reductase inhibitors with potential cardio-protective effects. SMe1EC2 is a promising new drug, exerting many positive effects in experimental settings. METHODS Rats with induced metabolic syndrome were treated with atorvastatin (25 mg/kg) and SMe1EC2 (25 mg/kg and 0.5 mg/kg, respectively) daily for 3 weeks. After the treatment, the hearts were isolated and perfused according to Langendorff. RESULTS Both atorvastatin and SMe1EC2 improved cardiac function by elevating the left ventricular developed pressure (VLDP) and cardiac contractility. Both SMe1EC2-treated groups improved LVDP during reperfusion, significantly increased ‒dP/dt, and moderately elevated +dP/dt values. The treatment with both atorvastatin and SMe1EC2 (25 mg/kg) significantly reduced malignant arrhythmia in comparison to control group and group treated with SMe1EC2 0.5 mg/kg. CONCLUSIONS Owing to its anti-arrhythmic and cardio-protective effects, atorvastatin and SMe1EC2 could be of benefit to patients suffering from metabolic syndrome (Tab. 3, Fig. 3, Ref. 41).

The aim of this study was to determine pharmacological possibilities of influencing the risk factors of metabolic syndrome (MetS). Hypertriacylglycerolemic (HTG) rats fed with high-fat-fructose diet (HFFD) were used as a model of the MetS. Wistar rats fed with standard diet were used as negative control group. HTG rats fed with HFFD for 8 weeks were used as positive control group. The effects of atorvastatin and SMe1EC2 were tested. The compounds were administered to the HTG rats after 5 weeks of HFFD, once a day for 3 weeks. After 8 weeks, the blood serum lipid profile and electrophysiology of neurotransmission in hippocampal sections were evaluated in vitro. SMe1EC2 and atorvastatin had a significant effect on total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-cholesterol) and atorvastatin had a significant effect on triacylglycerols (TGs). SMe1EC2 improved the long-term potentiation (LTP) course in the hippocampus.

The red-rimmed melania Melanoides tuberculata (O. F. Muller) has been used in the aquarist trade and biocontrol programs, leading to its emergence outside its native range. Two populations of the red-rimmed melania occur in Slovakia. We investigated the morphometric features of mentioned populations and made a comparison. These two populations differ significantly in investigated features. Mean shell length of red-rimmed melania individuals from the Opatovce nad Nitrou was 14.7 mm, while the mean shell length of specimens from Piesťany was 24.4 mm (p

Fat-rich diet (FRD) triggers health complications like hypertension, dyslipidemia, hyperglycemia, insulin resistance and non-alcoholic fatty liver disease, known as the risk factors of metabolic syndrome (MetS), which may result in neurological deficits. The impact of MetS on neuronal functions and brain morphology are poorly understood. We induced MetS-like conditions by exposing hypertriacylglycerolemic (HTG) rats to FRD for eight weeks with the aim to study possible neurological dysfunctions. HTG-FRD rats were compared to HTG rats and Wistar rats on standard diet. The physiological status of the animals was monitored by body, liver and kidney weight. Morphology of the liver, vessel wall and hippocampus were investigated. Basal neurotransmission and synaptic plasticity were measured in the hippocampus ex-vivo. A marked increase of liver weight with marks of steatosis was found in the HTG-FRD group. FRD induced an increase of aortic intima-media thickness. Extracellular recording revealed FRD-induced impairment of long-term potentiation (LTP) at Cornu Ammonis (CA)3-CA1 synapse, contrary to increased presynaptic fiber volley (pV). Reduced thickness of pyramidal cell layer at the CA1 area was found morphometrically. LTP was directly associated with kidney weight and inversely associated with liver weight, pV directly correlated with liver weight, liver/body wt ratio and aortic intima-media thickness. Our results suggest correlations between altered physiological status due to MetS-like conditions and neurological deficits, which may be related with consecutive development of so-called metabolic cognitive syndrome.

Biological invasions are increasingly recognized ecological and economic threats to biodiversity and are projected to increase in the future. Introduced freshwater crayfish in particular are protruding invaders, exerting tremendous impacts on native biodiversity and ecosystem functioning, as exemplified by the North American spiny-cheek, signal and red swamp crayfish as well as the Australian common yabby. The marbled crayfish is among the most outstanding freshwater crayfish invaders due to its parthenogenetic reproduction combined with early maturation and high fecundity. As their introduced ranges expand, their sympatric populations become more frequent. The question of which species and under what circumstances will dominate in their introduced communities is of great interest to biodiversity conservation as it can offer valuable insights for understanding and prioritization of management efforts. In order to examine which of the aforementioned species may be more successful as an invader, we conducted a set of independent trials evaluating survival, growth, claw injury, and reproduction using single-species stocks (intraspecific interactions) and mixed stocks (interspecific interactions) of marbled crayfish vs. other crayfish invaders since the onset of exogenous feeding. In both single and mixed stocks, red swamp crayfish and yabby grew faster than marbled crayfish, while marbled crayfish were superior to both spiny-cheek and signal crayfish in terms of growth. With the exception of signal crayfish, the faster-growing species consistently reached a higher survival rate. The faster-growing species tended to negatively impair smaller counterparts by greater claw injury, delayed maturation, and reduced fecundity. Only marbled crayfish laid eggs as early as 14 weeks in this study, which is earlier than previously reported in the literature. Thus, the success of marbled crayfish among invasive crayfish is significantly driven by relatively fast growth as well as an early and frequent reproduction. These results shed light on how interactions between invasive populations can unfold when their expansion ranges overlap in the wild, thereby contributing to the knowledge base on the complex population dynamics between existing and emerging invasive species

The aim of the work was to find an experimental model suitable for the study of endothelial dysfunction induced by MS. We used hypertriglyceridemic rats (HTG) that were fed a hypercholesterolemic diet of different composition and duration: a 6-week administration of standard diet with an addition of cholesterol and fat (HTGChol) and a three-month administration of the same diet with an addition of fructose (HTGCholF). We investigated the effect of different diets on aortic endothelial function. The standard diet fed Wistar (W) and HTG rats served as controls. Decision for addition of fructose to HTGChol was done based on in vitro experiments evaluating the effect of high concentration of saccharide in the incubation solution on aortic endothelial function. This intervention caused significant deterioration of relaxation induced by acetylcholine (ACh). While in HTGChol, we did not find significant differences in the function of the aorta compared to W or HTG rats, adding of fructose to high fat diet and prolonging its administration resulted in significantly impaired endothelium-dependent relaxation. It seems that such a model is suitable for the study of endothelial dysfunction in MS and the effect of substances that may protect the endothelium.

Hypokalemia prolongs the QRS and QT intervals, deteriorates intercellular coupling, and increases the risk for arrhythmia. Melatonin preserves gap junctions and shortens action potential as potential antiarrhythmic mechanisms, but its properties under hypokalemia remain unknown. We hypothesized that melatonin protects against low potassium-induced arrhythmias through the activation of its receptors, resulting in action potential shortening and connexin-43 preservation. After stabilization in Krebs-Henseleit solution (4.5 mEq/L K+), isolated hearts from Wistar rats underwent perfusion with low-potassium (1 mEq/L) solution and melatonin (100 μmol/L), a melatonin receptor blocker (luzindole, 5 μmol/L), melatonin + luzindole or vehicle. The primary endpoint of the study was the prevention of ventricular fibrillation. Electrocardiography was used, and epicardial action potentials and heart function were measured and analyzed. The ventricular expression, dephosphorylation, and distribution of connexin-43 were examined. Melatonin reduced the incidence of low potassium-induced ventricular fibrillation from 100% to 59%, delayed the occurrence of ventricular fibrillation and induced a faster recovery of sinus rhythm during potassium restitution. Melatonin prevented QRS widening, action potential activation delay, and the prolongation of action potential duration at 50% of repolarization. Other ECG and action potential parameters, the left ventricular developed pressure, and nonsustained ventricular arrhythmias did not differ among groups. Melatonin prevented connexin-43 dephosphorylation and its abnormal topology (lateralization). Luzindole abrogated the protective effects of melatonin on electrophysiological properties and connexin-43 misdistribution. Our results indicate that melatonin receptor activation protects against low potassium-induced ventricular fibrillation, shortens action potential duration, preserves ventricular electrical activation, and prevents acute changes in connexin-43 distribution. All of these properties make melatonin a remarkable antifibrillatory agent. Fil: Prado, Natalia Jorgelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina Fil: Egan Benová, Tamara. Institute for Heart Research; Eslovaquia Fil: Diez, Emiliano Raúl. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina Fil: Knezl, Vladimír. Institute of Experimental Pharmacology and Toxicology; Eslovaquia Fil: Lipták, Boris. Institute of Experimental Pharmacology and Toxicology; Eslovaquia Fil: Ponce Zumino, Amira Zulma. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas; Argentina Fil: Llamedo Soria, Mariano. Universidad Tecnológica Nacional; Argentina Fil: Szeiffová Bacová, Barbara. Institute for Heart Research; Eslovaquia Fil: Miatello, Roberto Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas; Argentina Fil: Tribulová, Narcisa. Institute for Heart Research; Eslovaquia

The aim of study was to search for new biomarkers with a magnetic resonance technique to identify the early stages of dementia, induced by d -galactose, and evaluate Simvastatin therapy. Localized proton magnetic resonance spectroscopy measurements showed a significant decrease in the concentration of N-acetylaspartate + N-acetylaspartylglutamate and myo-inositol in the d -galactose group compared to the control group, and, conversely, an increase of N-acetylaspartate + N-acetylaspartylglutamate in the d -galactose/Simvastatin group. Using a saturation transfer experiment, with phosphorus magnetic resonance spectroscopy, we observed a significant elevation of the forward rate constant of the creatine kinase reaction in the brains of the d -galactose group compared to controls, and subsequently, a significant reduction of this reaction in the d -galactose/Simvastatin group. Spatial learning and memory were evaluated using the modified Morris water maze test. The dynamics of the learning process represented by the learning index revealed a significant reduction in learning in the d -galactose group, but the deficits as a consequence of the d -galactose effects were recovered in the d -galactose/Simvastatin group, in which the learning dynamics resembled those of the control group. By determining the thiobarbituric acid reactive substances and total coenzyme Q 9 in plasma, we have shown that long-term administration of d -galactose created conditions for oxidative stress, and that the administration of Simvastatin decreased oxidative stress in plasma. Volumetry analyses from the hippocampal area show a reduction in the segmented area in the d -galactose group, compared with the control group, and an enlarged area in the hippocampus in the d -galactose/Simvastatin group.

Objectives Metabolic disturbances are considered to condition the occurrence of malignant heart arrhythmias and negatively influence the chances of a patient to survive. To test this assumption, a model of metabolic syndrome was selected in which rats were receiving a diet resembling that of the westernized population. Background Metabolic syndrome is a comorbidity of major cardiovascular risk factors (dyslipidemia, hypertension, impaired glucose tolerance or insulin resistance, diabetes mellitus, and obesity), all facilitating cardiovascular complications leading to morbidity and mortality of patients. Methods Hearts were isolated and perfused according to Langendorff. Global ischemia was induced in the hearts and arrhythmia occurrence in reperfusion was monitored. All hearts were stimulated with the electro-cardio-stimulator to test the electrical inducibility of heart arrhythmia. Results Isolated hearts from rats with the metabolic syndrome were more susceptible to ventricular arrhythmias. The high-fat diet increased the occurrence of malignant heart arrhythmias in rats with metabolic syndrome to an even greater extent. All subjects with metabolic syndrome were sensitive to ventricular tachyarrhythmia with significantly decreased threshold to its induction in cardio-stimulation. Conclusions These results indicate that metabolic syndrome patients may be more sensitive to the occurrence of malignant heart arrhythmias following myocardial infarction or other heart diseases (Tab. 1, Fig. 2, Ref. 34).

The marbled crayfish, Procambarus fallax f. virginalis, is a taxon widely available in the aquarium pet trade, which has been introduced to open waters in several European countries and in Madagascar. Recent studies confirmed this parthenogenetically reproducing crayfish as a high-risk invasive species, and vector of the crayfish plague pathogen, Aphanomyces astaci. It has been first discovered in Slovakia in 2010, but the status of the local population was not studied since then. Due to enlarged sampling area around the first report and one locality, where we presupposed the crayfish occurrence, we identified new marbled crayfish populations. Here, we report presence of three newly established marbled crayfish populations in Slovakia. Two populations are located critically close to the Váh River, a major tributary of the Danube River; one of them being directly connected to the Váh River via a side channel during occasional floods. The third established marbled crayfish population was found at the mouth of a thermal stream flowing into the Nitra River, a tributary of the Váh River. In this stream, crayfish coexist with other exotic fish and gastropod species of aquarium origin. We presume that the reported localities may serve as a source for further expansion of the marbled crayfish in the mid-part of the Danube catchment. Floods, active dispersal (including overland), passive dispersal by zoochory or anthropogenic translocations are among the major drivers facilitating the marbled crayfish colonization. We have not detected the crayfish plague pathogen in any of the studied populations. However, if spreading further, the marbled crayfish will encounter established populations of crayfish plague carriers in the Danube River, in which case they may acquire the pathogen by horizontal transmission and contribute to spread of this disease to indigenous European crayfish species.

Established populations of the non-indigenous parthenogenetically reproducing marbled crayfish Procambarus fallax f. virginalis have been recently reported from various European countries. The colonised sites are usually lentic and relatively isolated from major watercourses and in such cases the immediate threat of the spread of this taxon is limited. Here we report on a marbled crayfish population that is likely to become a seed for colonisation of the Danube in Slovakia. It is located in a channel within the Slovak capital Bratislava in the immediate vicinity of a pumping station that occasionally releases significant amounts of water into the side arm of the Danube. The population is well established with a high growth potential: numerous adult marbled crayfish individuals were observed at the site in September and October 2016 and the progeny (eggs or first two developmental stages) of 27 berried females exceeded 11 000 individuals. The maximum observed fecundity per female reached 647 juveniles in the second developmental stage. The Danube side arm downstream of the pumping station harbours a population of spiny-cheek crayfish Orconectes limosus infected with the crayfish plague pathogen Aphanomyces astaci . We presume that marbled crayfish is already present below the pumping station and it is just a matter of effort and time until it is discovered. The investigated specimens of marbled crayfish were found free of A. astaci , but horizontal transmission from infected spiny-cheek crayfish may be expected, as well as further spread of marbled crayfish in the Danube.

People with metabolic syndrome have higher risk of cardiovascular diseases then those without. The aim of the work was to investigate whether high fat diet administered to Prague hereditary hypertriglyceridemic (HTG) rats can induce signs of metabolic syndrome (MetS). Our results showed that HTG rats fed high fat diet (HTGch) had disturbed glucose metabolism and also lipid metabolism – increased serum triacylglycerols (TAG), total cholesterol (Ch), low-density lipoprotein-Ch (LDL-Ch), and decreased high-density lipoprotein-Ch (HDL-Ch). Their livers proved markers of developing steatosis. Moreover, HTGch had increased blood pressure, yet the vascular endothelium was not significantly damaged. All these changes were accompanied with oxidative stress and tissue damage identified as increased liver concentrations of thiobarbituric acid reactive substances (TBARS) and activity of the lysosomal enzyme N-acetyl-D-glucosaminidase (NAGA). We assume that the model used may be suitable for the study of MetS with no evidence of obesity. Prolongation of the high fat diet duration might have a major impact on all parameters tested, especially on vascular endothelial function.