Effect of Type-2 Diabetes Mellitus on the Expression and Function of Smooth Muscle ATP-Sensitive Potassium Channels in Human Internal Mammary Artery Grafts.

Here we have shown for the first time altered expression of the vascular smooth muscle (VSM) KATP channel subunits in segments of the human internal mammary artery (HIMA) in patients with type-2 diabetes mellitus (T2DM). Functional properties of vascular KATP channels in the presence of T2DM, and the interaction between its subunits and endogenous ligands known to relax this vessel, were tested using the potassium (K) channels opener, pinacidil. HIMA is the most commonly used vascular graft in cardiac surgery. Previously it was shown that pinacidil relaxes HIMA segments through interaction with KATP (SUR2B/Kir6.1) vascular channels, but it is unknown whether pinacidil sensitivity is changed in the presence of T2DM, considering diabetes-induced vascular complications commonly seen in patients undergoing coronary artery bypass graft surgery (CABG). KATP subunits were detected in HIMA segments using Western blot and immunohistochemistry analyses. An organ bath system was used to interrogate endothelium-independent vasorelaxation caused by pinacidil. In pharmacological experiments, pinacidil was able to relax HIMA from patients with T2DM, with sensitivity comparable to our previous results. All three KATP subunits (SUR2B, Kir6.1 and Kir6.2) were observed in HIMA from patients with and without T2DM. There were no differences in the expression of the SUR2B subunit. The expression of the Kir6.1 subunit was lower in HIMA from T2DM patients. In the same group, the expression of the Kir6.2 subunit was higher. Therefore, KATP channels might not be the only method of pinacidil-induced dilatation of T2DM HIMA. T2DM may decrease the level of Kir6.1, a dominant subunit in VSM of HIMA, altering the interaction between pinacidil and those channels.

Attributable mortality of infections caused by carbapenem-resistant Enterobacterales: results from a prospective, multinational case-control-control matched cohorts study (EURECA).

OBJECTIVES: To assess the mortality attributable to infections caused by carbapenem-resistant Enterobacterales (CRE) and to investigate the effect of clinical management on differences in observed outcomes in a multinational matched cohort study. METHODS: A prospective matched-cohorts study (NCT02709408) was performed in 50 European hospitals from March 2016 to November 2018. The main outcome was 30-day mortality with an active post-discharge follow-up when applied. The CRE cohort included patients with complicated urinary tract infections, complicated intra-abdominal infections, pneumonia, or bacteraemia from other sources because of CRE. Two control cohorts were selected: patients with infection caused by carbapenem-susceptible Enterobacterales (CSE) and patients without infection. Matching criteria included type of infection for the CSE group, hospital ward of CRE detection, and duration of hospital admission up to CRE detection. Multivariable and stratified Cox regression was applied. RESULTS: The cohorts included 235 patients with CRE infection, 235 patients with CSE infection, and 705 non-infected patients. The 30-day mortality (95% CI) was 23.8% (18.8-29.6), 10.6% (7.2-15.2), and 8.4% (6.5-10.6), respectively. The difference in 30-day mortality rates between patients with CRE infection when compared with patients with CSE infection was 13.2% (95% CI, 6.3-20.0), (HR, 2.57; 95% CI, 1.55-4.26; p < 0.001), and 15.4% (95% CI, 10.5-20.2) when compared with non-infected patients (HR, 3.85; 95% CI, 2.57-5.77; p < 0.001). The population attributable fraction for 30-day mortality for CRE vs. CSE was 19.28%, and for CRE vs. non-infected patients was 9.61%. After adjustment for baseline variables, the HRs for mortality were 1.87 (95% CI, 0.99-3.50; p 0.06) and 3.65 (95% CI, 2.29-5.82; p < 0.001), respectively. However, when treatment-related time-dependent variables were added, the HR of CRE vs. CSE reduced to 1.44 (95% CI, 0.78-2.67; p 0.24). DISCUSSION: CRE infections are associated with significant attributable mortality and increased adjusted hazard of mortality when compared with CSE infections or patients without infection. Underlying patient characteristics and a delay in appropriate treatment play an important role in the CRE mortality.

Resveratrol and Gut Microbiota Synergy: Preventive and Therapeutic Effects.

The role of an imbalanced high-fat diet in the pathophysiology of common chronic noncommunicable diseases has been known for years. More recently, the concept of 'gut microbiota' and the interaction between their composition and gut metabolites produced from the intake of dietary products have gained the focus of researchers, mostly from the perspective of the prevention of cardiovascular and metabolic disorders, which are still the leading cause of death globally. The aim of this work is to highlight the health benefits of the interaction between resveratrol (RSV), red grape polyphenol, and gut microbiota, through aspects of their therapeutic and preventive potentials. Since changed microbiota (mostly as a consequence of antibiotic overuse) contribute to the persistence of post ('long')-COVID-19 symptoms, these aspects will be covered too. Data were obtained from the electronic databases (MedLine/PubMed), according to specific keywords regarding the protective role of resveratrol, the gut microbiota, and their synergy. RSV exerts beneficial properties in the modulation of cardiovascular, metabolic, and post-COVID-19-related disorders. In healthy individuals, it maintains an ergogenic capacity, prevents oxidative stress, and modulates the inflammatory response. Overall, it improves quality of life. The RSV-gut-microbiota interaction is beneficial in terms of maintaining human health. Along with physical activity, it is key for the prevention of chronic noncommunicable diseases.

Resveratrol and Reproductive Health.

Resveratrol (RSV), a plant-derived polyphenol, demonstrates broad-spectrum health benefits, including anti-proliferative, anti-inflammatory, antidiabetic, anti-ischemic and antioxidant effects. The aim of this review is to give an important heads-up regarding the influence of RSV as a phytoestrogen, RSV effects on most common pregnancy-related complications, as well as its impact on the embryogenesis, spermatogenesis, and women's reproductive health. Considering the important implications of RSV on human reproductive health, this overview could provide a groundwork, encouraging more detailed research at the clinical level.

Design of experiments (DoE) to model phenolic compounds recovery from grape pomace using ultrasounds.

Grape processing by-products (particularly grape pomace) are known to contain high amounts of phenolic compounds. To improve the extraction of phenols from this by-product, it is necessary to develop a method and set and model optimal conditions for their extraction. By applying the design of experiments (DoE) approach, optimal experimental factors of Ultrasound-assisted extraction (USAE) were determined to obtain grape pomace extracts with a satisfactory yield of phenols anthocyanins, as well as extracts with high antioxidant capacity using reagents approved in the food industry. Initial method optimization covered two experimental factors: solvent concentration and the weight ratio of the sample and solvent using fixed USAE conditions from literature. For the final method optimization, the three investigated experimental factors were: pH value, the temperature of extraction, and extraction time. The optimal experimental conditions for the development of the method were 55% ethanol, sample/solvent ratio 1:40, pH 4.5, T 55 °C, and 30 min. Depending on the primary goal of the extraction process (the antioxidant activity, total phenolic content, content of individual phenols, or content of individual anthocyanins), these parameters can easily be modified to obtain the desired recovery. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-021-05317-9.

Potassium channels on smooth muscle as a molecular target for plant-derived Resveratrol.

Resveratrol (3,5,4'-trihydroxy-trans-stilbene) is a phytoalexin present in a variety of plant species. Resveratrol has a wide spectrum of pharmacologic properties, and it exhibits versatile biological effects on different human and animal models. The studies have shown that potassium (K) channels can be potential targets in the mechanism of resveratrol action. K channels play a crucial role in maintaining membrane potential. Inhibition of K channels causes membrane depolarization and then contraction of smooth muscles, while the activation leads to membrane hyperpolarization and subsequently, relaxation. Five diverse types of K channels have been identified in smooth muscle cells in different tissue: ATP-sensitive K channels (KATP), voltage-dependent K channels (Kv), Ca2+ - and voltage-dependent K channels (BKCa), inward rectifier K channels (Kir), and tandem two-pore K channels (K2P). The expression and activity of K channels altered in many types of diseases. Aberrant function or expression of K channels can be underlying in pathologies such as cardiac arrhythmia, diabetes mellitus, hypertension, preterm birth, preeclampsia, and various types of cancer. Modulation of K channel activity by molecular approaches and selective drug development may be a novel treatment modality for these dysfunctions in the future. The plant-derived non-toxic polyphenols, such as resveratrol, can alter K channel activity and lead to the desired outcome. This review presents the basic properties, physiological, pathophysiological functions of K channels, and pharmacological roles of resveratrol on the major types of K channels that have been determined in smooth muscle cells.

Pregnancy-induced hypertension decreases Kv1.3 potassium channel expression and function in human umbilical vein smooth muscle.

Voltage-gated potassium (Kv) channels are the largest superfamily of potassium (K) channels. A variety of Kv channels are expressed in the vascular smooth muscle cells (SMC). Studies have shown that gestational diabetes mellitus (GDM) and pregnancy-induced hypertension (PIH) cause various changes in the human umbilical vein (HUV). Recently, we have shown that 4-AP, a nonspecific Kv1-4 channel inhibitor, significantly decreases vasorelaxation induced by K channel opener pinacidil in vascular SMCs of the HUVs from normal pregnancies, but not in GDM and PIH. The goal of this study was to provide more detailed insight in the Kv channel subtypes involved in pinacidil-induced vasodilation of HUVs, as well as to investigate potential alterations of their function and expression during GDM and PIH. Margatoxin, a specific blocker of Kv1.2 and Kv1.3 channels, significantly antagonized pinacidil-induced vasorelaxation in normal pregnancy, while in HUVs from GDM and PIH that was not the case, indicating damage of Kv1.2 and Kv1.3 channel function. Immunohistochemistry and Western blot revealed similar expression of Kv1.2 channels in all groups. The expression of Kv1.3 subunit was significantly decreased in PIH, while it remained unchanged in GDM compared to normal pregnancy. Phrixotoxin, specific blocker of Kv4.2 and Kv4.3 channels, did not antagonize response to pinacidil in any of the groups. The major novel findings show that margatoxin antagonized pinacidil-induced relaxation in normal pregnancy, but not in GDM and PIH. Decreased expression of Kv1.3 channels in HUV during PIH may be important pathophysiological mechanism contributing to an increased risk of adverse pregnancy outcomes.

The influence of climate change on human cardiovascular function.

Climate change is considered to have great impact on human health. The heat waves have been associated with excess morbidity and mortality of cardiovascular diseases (CVD) across various populations and geographic locations. Important role in the heat-induced cardiovascular damage has endothelial dysfunction. It has been noticed that hot weather can impair tone and structure of the blood vessels via interfering with variety of biological factors such as nitric oxide synthesize, cytokine production and systemic inflammation. Also, due to dehydration and increased blood viscosity, by promoting thrombogenesis, heat has important impact on patients with atherosclerosis. During chronic exposure to the cold or hot weather cardiovascular function can be decreased, leading to a higher risk of developing heart attack, malignant cardiac arrhythmias, thromboembolic diseases and heat-induced sepsis like shock. It has been shown that changes in the ambient temperature through increasing blood pressure, blood viscosity, and heart rate, contribute to the cardiovascular mortality. The majority of deaths due to heat waves especially affect individuals with preexisting chronic CVD. This population can experience a decline in the health status, since extreme ambient temperature affects pharmacokinetic parameters of many cardiovascular drugs. Increased mortality from ischemic or hemorrhagic stroke can also be related to extreme temperature variations. On a cellular level, higher ambient temperature can limit storage of ATP and O2 increase amount of free radicals and toxic substances and induce neuronal apoptotic signal transduction, which all can lead to a stroke. Preserving cardiovascular function in context of extreme climate changing tends to be particularly challenging.

Effect of gestational diabetes mellitus and pregnancy-induced hypertension on human umbilical vein smooth muscle KATP channels.

Gestational diabetes mellitus (GDM) and pregnancy-induced hypertension (PIH) can jeopardize mother and/or fetus. Vascular ATP-sensitive potassium (KATP) channels most likely participate in the processes of diabetes and hypertension. The aim of this research was to examine whether GDM and PIH cause changes in the expression and function of KATP channels in vascular smooth muscle of human umbilical vein (HUV). Western blot and immunohistochemistry detected significantly decreased expression of Kir6.1 subunit of KATP channels in GDM and PIH, while the expression of SUR2B was unchanged. In GDM, a K+ channel opener, pinacidil caused reduced relaxation of the endothelium-denuded HUVs compared to normal pregnancy. However, its effects in HUVs from PIH subjects were similar to normal pregnancy. In all groups KATP channel blocker glibenclamide antagonized the relaxation of HUV induced by pinacidil without change in the maximal relaxations indicating additional KATP channel-independent mechanisms of pinacidil action. Iberiotoxin, a selective antagonist of large-conductance calcium-activated potassium channels, inhibited the relaxant effect of pinacidil in PIH, but not in normal pregnancy and GDM. Experiments performed in K+-rich solution confirmed the existence of K+-independent effects of pinacidil, which also appear to be impaired in GDM and PIH. Thus, the expression of KATP channels is decreased in GDM and PIH. In GDM, vasorelaxant response of HUV to pinacidil is reduced, while in PIH it remains unchanged. It is very likely that KATP channels modulation and more detailed insight in KATP channel-independent actions of pinacidil may be precious in the therapy of pathological pregnancies.

Resveratrol supplementation improves metabolic control in rats with induced hyperlipidemia and type 2 diabetes.

Resveratrol was recognized as the major factor responsible for the beneficial properties of red wine. Several resveratrol-based dietary supplements are available, but their efficacy has not been sufficiently tested. This study was designed to examine the effect of resveratrol supplementation, using a commercially available product, on the metabolic status of experimental animals with induced hyperlipidemia or type 2 diabetes mellitus (T2DM). Hyperlipidemia was induced by feeding the rats a standard pellet diet supplemented with cholesterol. T2DM was induced by adding 10% fructose to drinking water and streptozotocin. Treatment with resveratrol-based supplement improved glycemic control in diabetic animals and significantly decreased serum low-density-lipoprotein (LDL) and triglyceride levels, concurrently increasing the high-density-lipoprotein (HDL) levels in animals with hyperlipidemia. Resveratrol-treated animals had improved tolerance to glucose loading. Supplementation did not induce alterations in parameters of liver and renal function. Findings indicate that commercial resveratrol supplement improves metabolic control in rats with induced hyperlipidemia and T2DM.

Differences in antimicrobial consumption, prescribing and isolation rate of multidrug resistant Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii on surgical and medical wards.

In order to provide guidance data for clinically rational use of an antibiotics consuption, prescribing and prevalence of multidrug resistant (MDR) Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii were monitored on the surgical (S) and medical (M) wards of the University Hospital Center "Dr. Dragisa Misovic-Dedinje" (Belgrade, Serbia), in the study period from 2012 to 2015. Appropriateness of antimicrobial use was evaluated using the Global-Prevalence Survey method designed by the University of Antwerp. The percentages of MDR pathogens relative to the total number of isolates of K. pneumoniae and P. aeruginosa were higher on the S (86.2% and 49.1%) than on the M (63.2% and 36.9%) wards. The percentage of MDR A. baumannii was not different between S (93.7%) and M (79.5%) wards. An overall antibiotics consumption (defined daily doses/100 bed-days) during study was 369.7 and 261.5 on the S and M wards, respectively. A total of 225 prescriptions of antimicrobials were evaluated in138 adults admitted to wards on the day of the survey. The percentage of antimicrobials prescribed for prophylaxis on the M and S wards were 0% and 25%, respectively. Therapies were more frequently empiric (S, 86.8% and M, 80%). The percentages of medical errors on the S and M wards were 74.6% and 27.3%, respectively. The quality indicators for antibiotic prescribing on the S and M wards were as follows: the incorrect choice of antimicrobials (35.6% vs. 20.0%), inappropriate dose interval (70.6% vs. 16.9%) or duration of therapy (72.5% vs. 23.1%), a non-documented stop/review data (73.6% vs. 16.9%) and divergence from guidelines (71.9% vs. 23.1%). Treatment based on biomarkers was more common on the M wards as compared to the S wards. The increasing prevalence of MDR pathogens, a very high consumption and incorrect prescribing of antimicrobials need special attention, particularly on the S wards.

The Role of Potassium Channels in the Vasodilatation Induced by Resveratrol and Naringenin in Isolated Human Umbilical Vein.

Preclinical Research Potassium (K+ ) channels have a key role in the maintenance of smooth muscle tone; a variety of agonists can modify the tone by altering K+ -channel activity. The aim of this study was assess the effects of the phenols, resveratrol, and naringenin on K+ -channels of the vascular smooth muscle. Segments of human umbilical vein (HUV) without endothelium were precontracted using serotonin (100 µM) or 100 mM K+ to derive cumulative concentration-response curves using increasing concentrations of resveratrol or naringenin. K+ -channel inhibitors were added in the bath before resveratrol (1-100 µM) or naringenin (0.01-1 mM) in assess the role of K+ -channels in their effects on HUV precontracted by serotonin. 4-Aminopiridine (4-AP; 1 mM), a nonselective blocker of voltage-dependent, tetraethylammonium (TEA; 1 mM) and barium chloride (1 mM), a nonselective blocker of Ca2+ -dependent and inward rectifier K+ -channels (respectively) induced significant shifts to the right (P < 0.05) of resveratrol. concentration-response curves. The effect of naringenin was antagonized by 4-AP (1 mM). 4-AP-, TEA-, and barium chloride-sensitive K+ -channels are probably involved in the resveratrol vasodilatatory effect, while naringenin seems to affect 4-AP-sensitive K+ -channels. However, other mechanisms of vasodilation induced by polyphenols could not be excluded. Drug Dev Res, 2015. © 2015 Wiley Periodicals, Inc.

Left and right atrial phasic function and deformation in untreated patients with prediabetes and type 2 diabetes mellitus.

To evaluate phasic function and deformation of the left atrium (LA) and right atrium (RA) in subjects with prediabetes and type 2 diabetes mellitus. This cross-sectional study included 50 untreated normotensive subjects with prediabetes, 60 recently diagnosed normotensive diabetic patients and 60 healthy controls of similar sex and age. All the subjects underwent laboratory analyses and complete echocardiographic examination including strain analysis. LA and RA reservoir and conduit function gradually decreased, while booster pump increased, from the healthy controls, throughout the prediabetics, to the diabetics. The strain analysis of atrial phasic function showed more regular pattern of progressive atrial function deterioration than conventional evaluation with total, active and passive atrial function. In the whole study population HbA1c correlated with LA passive emptying fraction (r = -0.38, p < 0.01), LA active emptying fraction (r = 0.36, p < 0.01), LA longitudinal strain during systole (r = -0.35, p < 0.01), RA passive emptying fraction (r = -0.42, p < 0.01), RA active emptying fraction (r = 0.38, p < 0.01), and RA longitudinal strain during systole (r = -0.32, p < 0.01). However, only LA passive emptying fraction (ß = -0.32, p < 0.01) and LA longitudinal strain during systole (ß = -0.28, p = 0.02) were independently associated with HbA1c among the LA parameters; whereas solely RA passive emptying fraction (ß = -0.37, p < 0.01) and RA active emptying fraction (ß = 0.31, p = 0.01) were independently associated with HbA1c among the RA parameters. LA and RA phasic functions are significantly impaired in the prediabetics and the diabetics. The parameter of glucose control correlated with LA and RA reservoir, conduit and pump atrial function.

Left Ventricular Mechanics in Untreated Normotensive Patients with Type 2 Diabetes Mellitus: A Two- and Three-dimensional Speckle Tracking Study.

BACKGROUND: Our aim was to investigate left ventricular (LV) mechanics estimated by two- (2DE) and three-dimensional echocardiography (3DE) strains in subjects with type 2 diabetes mellitus (DM). METHODS: This cross-sectional study included 50 untreated normotensive DM subjects and 50 healthy controls similar by sex and age. All the subjects underwent adequate laboratory analyses and complete 2DE and 3DE examination. RESULTS: Left ventricular mechanics, assessed by 2DE, was impaired in all three directions. Global longitudinal 3DE strain was significantly decreased in the DM group in comparison with the controls (-17.8 ± 2.5 vs. -19.1 ± 2.7%, P = 0.014). Similar results were found for 3DE global circumferential strain (-18.9 ± 2.9 vs. -20.4 ± 3.2%, P = 0.01), 3DE global radial strain (40.3 ± 6.9 vs. 43.1 ± 7.3%, P = 0.035), and 3DE global area strain (-29.2 ± 3.7 vs. -31 ± 4%, P = 0.024). LV torsion was similar between the DM patients and the controls (2.1 ± 0.6 vs. 1.9 ± 0.5 °/cm, P = 0.073); whereas LV untwisting rate was significantly increased in the DM subjects (-114 ± 26 vs. -96 ±23 °/s, P < 0.001). A multivariate analysis showed that 3DE global longitudinal and area myocardial functions were associated with HbA1c independently of 3DE LV mass index. CONCLUSION: Left ventricular deformation obtained by 3DE is significantly impaired in the type 2 DM patients. HbA1c is independently associated with LV mechanics that implies that early anti-diabetic therapy and normalization of the fasting glucose level and HbA1c could impede further cardiac damage.

Quantification of the acute effect of a low dose of red wine by nonlinear measures of RR and QT interval series in healthy subjects.

The measures of nonlinear properties of RR interval and QT interval time series are sensitive to physiologically- or pathologically-induced complexity/regularity changes, but were not used to estimate the effect of alcohol intake. We wanted to examine the potential of these measures to quantify the acute effect of a low dose of red wine in healthy subjects. In separate experiments, fourteen young volunteers drank 200ml of red wine and a control drink with equal concentration of ethanol. ECG in supine position was recorded 20min before and 60min after drink intake. RR interval and QT interval series were extracted from ECG and we calculated variability, scaling exponents (α1 and α2) and sample entropy (SampEn) for both series. Systolic and diastolic blood pressures (BP) were measured every 10min. The immediate effect of both the drinks was equal: HR, BP and QT variability exhibited a sudden increase and then a decrease. However, the prolonged effect of wine and the control drink was different. Wine decreased both BP (p<0.05) and reduced complexity of RR and QT series (increased scaling exponents and decreased SampEn). The control drink prolonged QT and RR intervals (p<0.05). These results point out that the nonlinear properties of RR and QT interval series could be used to differentiate the effect of wine and ethanol. Changes in RR and QT interval series induced by a low dose of red wine are more detectable by methods that quantify the structure of the series than by methods that quantify their variability.

The different effects of resveratrol and naringenin on isolated human umbilical vein: the role of ATP-sensitive K⁺ channels.

The blood flow from the placenta to the fetus depends on human umbilical vein (HUV) vascular tone. ATP-sensitive K(+) (K(ATP)) channels link the metabolic state of the cell to membrane potential, and their activation in the HUV represents protection against hypoxia. The aims of our study were to assess the effects of resveratrol and naringenin on the HUV and to define the roles of K(ATP) channels in their effects. Serotonin or 100 mM K(+) were used for precontraction of the HUV without endothelium. The cumulative concentration-response curves were obtained by adding increasing concentrations of resveratrol or naringenin. Glibenclamide was used, in order to test the role of K(ATP) channels in its effect. Resveratrol induced more potent vasodilatation of serotonin- and 100 mM K(+)-precontracted HUV than naringenin. Glibenclamide induced significant shift to the right of the concentration-response curves of resveratrol and P1075 (a specific opener of K(ATP) channels). Western blotting showed that HUV expressed protein Kir6.1. Thus, resveratrol and naringenin produce dilatation of HUV. It seems that K(ATP) channels are involved in the relaxation of HUV induced by resveratrol, while naringenin seems to interact with other ion channels. The K(+) channel-independent mechanism(s) of these polyphenols could not be excluded.

[The effects of resveratrol on rat behaviour in the forced swim test].

INTRODUCTION: The trans-isomer of resveratrol is the active ingredient of Poligonum cuspidatum, known for its medicinal properties and traditionally used in the treatment of neuropsychiatric disorders. It is also found abundantly in the skin of red grapes and red wine. Previous studies have suggested that trans-resveratrol demonstrates a variety of pharmacological activities including antioxidant, anti-inflammatory, as well as neuroprotective properties and procognitive effects. OBJECTIVE: The goal of the present study was to examine the influence of trans-resveratrol on behavior in rats and its antidepressant properties. METHODS: Male Wistar rats were treated intraperitoneally (i.p.) with the increasing doses of trans-resveratrol (5, 10 and 20 mg/kg) or vehicle (dimethyl sulfoxide--DMSO), 30 minutes before testing of the spontaneous locomotor activity or forced swimming. For the experiments, the behavior of the animals was recorded by a digital camera, and the data were analyzed by one-way ANOVA, followed by Tukey post-hoc test. RESULTS: Testing of spontaneous locomotor activity, after the application of vehicle or increasing doses of trans-resveratrol, showed no statistically significant difference between groups (p > 0.05). In the forced swim test, one-way ANOVA indicated statistically significant effects of trans-resveratrol (p < 0.001).Tukey post-hoc test showed that resveratrol significantly decreased immobility time at the doses of 10 mg/kg and 20 mg/kg, manifesting the acute antidepressant-like effects. There were no statistically significant differences between the resveratrol treatment of 5 mg/kg and vehicle (p > 0.05). CONCLUSION: The results from our study suggest that transresveratrol produces significant effects in the central nervous system. After single application, it has acute antidepressant effects, but without influence on locomotor activity.

Contractions of the whole and longitudinally cut rat's portal vein.

To investigate the role of lateral interactions, we quantified spontaneous contractions of whole and longitudinally cut rat´s portal vein in vitro. The disruption of the wall had no effect on basic frequency determined from spectra and complexity index (CI) calculated by multiscale entropy analysis. Endothelium was disrupted and nonfunctional in all samples. Considering amplitude, frequency and CI we identified two modes of contractions. Neither mode of contractions nor the effect of aminopyridine (4-AP) depended on the integrity of the wall. We concluded that contractions in vitro originate in smooth muscle cells without involvement of the endothelium and lateral interactions.

Effect of wine polyphenol resveratrol on the contractions elicited electrically or by norepinephrine in the rat portal vein.

We investigated the effects of resveratrol on rat portal vein (RPV) contractility without endothelium. Contractions were produced by electrical field stimulation of perivascular nerves (EFS), norepinephrine (NE), adenosine 5'-triphosphate (ATP), high K(+) solution and by calcium chloride (CaCl2 ) in Ca(2+) -free and high K(+) , Ca(2+) -free solution. The EFS-evoked contractions were more sensitive to resveratrol and to NS1619-selective openers of big calcium-sensitive (BKCa ) channels, than NE-evoked contractions. Effects of resveratrol on the ATP-evoked contractions were weak. Blockers of BKCa channels partly inhibited the effect of resveratrol only in EFS-contracted preparations. Western blotting showed that RPV expressed KCa 1.1 protein. Inhibitors of ATP- and voltage-sensitive K(+) channels did not modify the effects of resveratrol. None of the antagonists of K(+) channels affected the resveratrol inhibition of NE-evoked contractions and effect of high concentrations of resveratrol on the EFS-evoked contractions. Resveratrol more potently inhibited CaCl2 than potassium chloride contractions of RPV. Thus, BKCa channels partly mediate the inhibitory effect of resveratrol on the neurogenic contractions of RPV. The smooth muscle Ca(2+) channels and/or Ca(2+) mobilizing through cells might be involved in the effects of resveratrol on the contractility of RPV. Our results are important for better understanding the impact of resveratrol on the portal circulation.