Pulmonary hypertension resulting from chronic hypoxia is at least partly caused by the increased production of reactive oxygen species (ROS). The goal of the presented study was to investigate the dynamics and the site of production of ROS during chronic hypoxia. In our study Wistar rats were kept for 1, 4 and 21 days in an isobaric hypoxic chamber (FiO2=0.1), while controls stayed in normoxia. We compared NO production in expired air, plasma and perfusate drained from isolated rat lungs and measured superoxide concentration in the perfusate. We also detected the presence of superoxide products (hydrogen peroxide and peroxynitrite) and the level of ROS-induced damage expressed as the concentration of lipid peroxydation end products. We found that the production and release of ROS and NO during early phase of chronic hypoxia has specific timing and differs in various compartments, suggesting the crucial role of ROS interaction for development of hypoxic pulmonary hypertension., D. Hodyc ... [et al.]., and Obsahuje seznam literatury
Whole cell patch-clamp recordings from GABAergic cells of thalamic reticular nucleus (RTN) in thalamocortical slices made from postnatal day 6 (P6) to 10 (P10) were used to investigate the pattern of rebound bursts (RBs) triggered by an injection of hyperpolarizing current into RTN cells. The number of RBs in the RTN and the overlying Na+/K+ spikes changed in an agedependent manner. The generation of RBs depended largely on the amplitude of the after-hyperpolarizations (AHPs). RB patterns in response to hyperpolarizing current injection into relay cells were markedly different from RB patterns in RTN cells with an after-depolarization. GABAA receptor antagonist bicuculline methiodide (BMI) changed burst firing patterns, increasing the duration of RB and decreasing the amplitude of AHP in RTN cells. Furthermore, local puffs of NMDA in the presence of BMI induced RBs. K+ channel blocker 4-aminopyridine partially mimicked the effect of BMI on AHPs. The shapes of RBs were altered by a selective CaMKII inhibitor KN-62, but not by an inactive analog KN-04., X. Wang ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
The spontaneously hypertensive rat (SHR) is the most widely used animal model of essential hypertension an d accompanying metabolic disturbances. Recent advances in sequencing of genomes of BN- Lx and SHR progenitors of the BXH/HXB recombinant inbred (RI) strains as well as ac cumulation of multiple data sets of intermediary phenotypes in the RI strains, including mRNA and microRNA abundance, quantitative metabolomics, proteomics, methylomics or histone modifications, will make it possible to systematically search for genetic variants involved in regulation of gene ex pression and in the etiology of complex pathophysiological traits. New advances in manipulation of the rat genome, including e fficient transgenesis and gene targeting, will enable in vivo functional analys es of selected candidate genes to identify QTL at the molecular level or to provide insight into mechanisms whereby targeted genes affect pathophysiological traits in the SHR., M. Pravenec ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Sepsis is a life threatening condition that arises when the body's response to an infection injures its own tissues and organs. Sepsis can lead to shock, multiple organ failure and death especially if not recognized early and treated promptly. Molecular mechanisms underlying the systemic inflammatory response syndrome associated with sepsis are still not completely defined and most therapies developed to target the acute inflammatory component of the disease are insufficient. In this s tudy we investigated a possibility of combating sepsis in a mouse model by intravenous treatment with recombinant human tissue non - specific alkaline phosphatase (rhTNAP) derived from transgenic rabbit milk. We induced sepsis in mice by intraperitoneal inje ction of LPS and three hours later treated experimental group of mice by intravenous injection with rhTNAP derived from transgenic rabbits. Such treatment was proved to be physiologically effective in this model, as administration of recombinant rhTNAP suc cessfully combated the decrease in body temperature and resulted in increased survival of mice (80 % vs. 30 % in a control group). In a control experiment, also the administration of bovine intestinal alkaline phosphatase by intravenous injection proved to be effective in increasing survival of mice treated with LPS. Altogether, present work demonstrates the redeeming effect of the recombinant tissue non -specific AP derived from milk of genetically modified rabbits in combating sepsis induced by LPS., B. Bender, M. Baranyi, A. Kerekes, L. Bodrogi, R. Brands, P. Uhrin, Z. Bösze., and Obsahuje bibliografii
The effect of antigenic bacterial lysate IRS-19 on the recovery of blood cells was studied in mice injured by a single dose of 7 Gy irradiation. The preirradiation administration of IRS-19 accelerated the recovery of leukocytes, reticulocytes and platelets in peripheral blood. The recovery of leukocytes 9-14 days after irradiation in protected animals was accompanied by a higher level of band forms of granulocytes as well as activated lymphoid and monocytoid cells., N.O. Macková, P. Fedoročko., and Obsahuje bibliografii
Increased amount of collagen type I and decreased amount of type III is described in various pathological processes in the vascular wall. Polyphenols were shown to have protective effect on endothelium, decrease blood pressure and prevent oxidative damage induced by various stimuli. Tetrachlormethane (CCl4) is a toxic substance with known negative systemic effects induced by free radicals. Chronic administration of CCl4 for 12 weeks led to an increase of collagen type I and a decrease of type III in the wall of aorta. Parallel administration of red wine polyphenols significantly reduced the increase of collagen type I, at the same time the content of type III rose to the level above controls. After 4 weeks of spontaneous recovery no changes were observed. If polyphenols were administered during the recovery period, there was a decrease of type I and an increase of type III collagen content in the aorta. It can be concluded that polyphenols have a tendency to lower the amount of type I and to increase the proportion of type III collagen in the wall of the aorta. These changes are significant in prevention or in regression of changes induced by chronic oxidative stress. This effect of polyphenols is most likely the result of their influence on MMP-1 and TIMP activities through which they positively influence the collagen types I and III content ratio in the vascular wall in favor of the type III collagen., L. Hlavačková ... [et al.]., and Obsahuje seznam literatury
The aim of the present study was to investigate the mechanism of vasorelaxant responses induced by red wine polyphenolic compounds (Provinol). Rings of rat femoral artery with or without functional endothelium were set up in a myograph for isometric recording and precontracted with phenylephrine (10-5 M). Provinol in cumulative doses (10-9 to 10-3 mg/ml) elicited endothelium- and dose-dependent relaxation of the artery with maximal relaxation of 56 % at the concentration of 10-5 mg/ml. The relaxant responses to Provinol correlated well with the increase of NO synthase activity in the vascular tissue after administration of cumulative doses of Provinol (10-9 to 10-3 mg/ml). NG-nitro-L-arginine methylester (L-NAME, 3x10-4 M) significantly attenuated the endothelium-dependent relaxation produced by Provinol. Administration of L-arginine (3x10-5 M) restored the relaxation inhibited by L-NAME. The relaxant responses of Provinol were abolished in the presence of Ca2+-entry blocker, verapamil (10-6 M). Administration of hydrogen peroxide (H2O2) abolished acetylcholine (10-5 M)-induced relaxation of the rat femoral artery, while administration of Provinol (10-5 mg/ml) together with H2O2 helped to maintain the acetylcholine-induced relaxation. Provinol only partially affected the concentration-response curve for the NO donor sodium nitroprusside-induced relaxation in rings without endothelium. In conclusion, Provinol elicited endothelium-dependent relaxation of rat femoral artery by the Ca2+-induced increase of NO synthase activity and by protecting NO from degradation., W. Zenebe, O. Pecháňová, R. Andriantsitohaina., and Obsahuje bibliografii
Flavonoids, polyphenol derivatives of plant origin, possess a broad range of pharmacological properties. A number of studies have found both pro/anti-apoptotic effects for many of these compounds. For these reasons we investigated whether ProvinolsTM, flavonoids obtained from red wine, have anti-apoptotic properties. The investigations have been carried out in rats treated with Cyclosporine A (CsA). In particular, four groups of rats have been treated for 21 days with either olive oil (control group), with CsA, with ProvinolsTM, or with CsA and ProvinolsTM simultaneously. Oxidative stress, systolic blood pressure, body weight, biochemical parameters and different markers of pro/anti-apoptotic pathway were measured. CsA produced an increase of systolic blood pressure, a decrease in body weight, serum creatinine levels, urinary total protein concentration and creatinine clearance. Moreover, CsA induced renal alterations and the translocation of Bax and cytochrome c from cytoplasm to mitochondria and vice versa. These changes activated the caspase cascade pathway, that leads to morphological and biochemical features of apoptosis. ProvinolsTM restored morphological and biochemical alterations and prevented nephrotoxicity. In conclusion, this study may augment our current understanding of the controversial pro-/anti-apoptotic properties of flavonoids and their molecular mechanisms., R. Rezzani ... [et al.]., and Obsahuje seznam literatury
Elevated levels of glucocorticoids lead to the development of obesity and metabolic syndrome. Local glucocorticoid levels are regulated through the enzyme 11 β -hydroxysteroid dehydrogenase 1 (11 β -HSD 1), an enzyme that regenerates active cortisol from inert cortis one. Increased expression of 11 β - HSD 1 in adipose tissue promotes higher body mass index (BMI), insulin resistance, hypertension, and dyslipidemia. Human 11 β - HSD 1 is also responsible for inter-conversion of 7-hydroxylate metabolites of dehydroepiandrosterone (7-OH-DHEA) to their 7-oxo-form. To better understanding the mechanism of the action, we focused on 7-OH- and 7-ox o-DHEA, and their circulating levels during the reductive treatment in adolescent obese patients. We determined plasma levels of 7 α -OH-DHEA, 7 β -OH- DHEA, and 7-oxo-DHEA in 55 adolescent patients aged 13.04- 15.67 years, BMI greater than 90 th percentile. Samples were collected before and after one month of reductive therapy. Circulating levels of 7 α -OH-DHEA decreased during the reductive therapy from 1.727 (1.614; 1.854 , transformed mean with 95 % confidence interval) to 1.530 nm ol/l (1.435; 1.637, p<0.05) in girls and from 1.704 (1.583; 1. 842) to 1.540 nmol/l (1.435; 1.659, p<0.05) in boys. With regard to the level of 7-oxo-DHEA, a significant reduction from 1. 132 (1.044; 1.231) to 0.918 nmol/l (0.844; 1.000, p<0.05) was found after the treatment, but only in boys. No significant difference in 7 β -OH-DHEA levels was observed. In conclusions, diminished levels of 7 α -OH-DHEA indicate its possible effect on activity of 11 β -HSD 1. Further studies are necessary to clarify whether competitive substrates for 11 β -HSD 1 such as 7 α -OH-DHEA could inhibit production of glucocorticoids and may be involved in metabolic processes leading to reduction of obesity., L. Máčová ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy