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892. Microalbuminuria versus brain natriuretic peptide in cardiac hypertrophy of hypertensive rats
- Creator:
- Saliba, Y., Chouery, E., Mégarbané, A., Jabbour, H., and Farès, N.
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, hypertenze, hypertension, microalbuminuria, brain natriuretic peptide, cardiac hypertrophy, 14, and 612
- Language:
- English
- Description:
- The objective of this study was to assess a possible link between microalbuminuria (MA), a major ri sk factor of the cardiorenal syndrome and the brain natriuretic peptide (BNP), a marker of cardiac hypertrophy. Two kidney-one clip (2K-1C) renovascular hypertension was induced in 24 male Wistar rats (weighing 220-250 g). Rats were randomized into four groups for 8 weeks: Sham, not treated; Bos, treated with bosentan; Cap, treated with captopril; Bos/Cap, treated with both drugs. Blood pressure, plasma BNP and transforming growth factor β1 (TGF-β1) concentrations, microalbuminuria and creatininemia as well as cardiac mass, BNP, α- and β-myosin heavy chain (MHC) gene expression and kidney histology were determined. Following stenosis, Sham rats developed hypertension (p<0.001), an increase in BNP (p<0.05) and TGF-β1 (p<0.005) concentrations, creatinine levels (p<0.001), and urinary albumin (p<0.001). Under drug treatment, decreases in blood pressure (p<0.001), creatinine levels (p<0.05), plasma TGF-β1 (p<0.005) and BNP (p<0.05) concentrations, were co ncomitant with the absence of MA which was significantly correlated with reductions in cardiac mass (p<0.05) and hypertrophy markers (BNP and β-MHC gene expression) (p<0.005) as well as in renal fibrosis. These findings suggest a potential link between microalbuminuria evolution and BNP as well as a possible effect of microalbuminuria-lowering therapy on halting the progression, or even inducing the regression of cardiac hypertrophy., Y. Saliba, E. Chouery, A. Mégarbané, H. Jabbour, N. Farès., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
893. Microarray analysis of normal and abnormal chick ventricular myocardial development
- Creator:
- Krejčí, E., Pesevski, Z., Dealmeida, A. C., Mrug, M., Fresco, V. M., Argraves, W. S., Barth, J. L., Cui, X., and David Sedmera
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie člověka, human physiology, gene chip array, chick embryo, left atrial ligation, hypoplastic left heart syndrome, 14, and 612
- Language:
- English
- Description:
- The left and right ventricle originate from distinct parts of the cardiac tube, and several genes are known to be differentially expressed in these compartments. The aims of this study were to determine developmental differences in gene expression between the left and right ventricle, and to assess the effect of altered hemodynamic loading. RNA was extracted from isolated left and right normal chick embryonic ventricles at embryonic day 6, 8, and 10, and from day 8 left atrial ligated hearts with hypoplastic left and dilated right ventricles. cRNA was hybridized to Affymetrix Chicken Genome array according to manufacturer protocols. Microarray analysis identified 302 transcripts that were differentially expressed between the left and right ventricle. Comparative analysis detected 91 genes that were different in left ventricles of ligated hearts compared to age-matched ventricles, while 66 were different in the right ones. A large number of the changes could be interpreted as a delay of normal maturation. The approach described in this study could be used as one of the measures to gauge success of surgical procedures for congenital heart disease and help in determining the optimal time frame for intervention to prevent onset of irreversible changes., E. Krejčí, ... [et al.]., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
894. Microcirculation in pregnancy
- Creator:
- Abdo, I., George, R. B., Farrag, M., and Černý, V.
- Format:
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- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, těhotenství, preeklampsie, diabetes mellitus, pregnancy, preeclampsia, microcirculation, gestational, 14, and 612
- Language:
- English
- Description:
- The microcirculation, like all physiological systems undergoes modifications during the course of pregnancy. These changes aid the adaption to the new anatomical and physiological environment of pregnancy and ensure adequate oxygen supply to the fetus. Even though the microcirculation is believed to be involved in major pregnancy related pathologies, it remains poorly understood. The availability of safe and non-interventional technologies enabling scientists to study the intact microcirculation of the pregnant patient will hopefully expand our understanding. In this article we review the physiological changes occurring in the microcirculation during pregnancy and the role of the microcirculation in gestational related pathologies. We will also describe the available techniques for the measurement and evaluation of the microcirculation. Lastly we will highlight the possible fields in which these techniques could be utilized to help provide a clearer view of the microcirculation in the pregnant woman., I. Abdo, R. B. George, M. Farrag, V. Cerny, C. Lehmann., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
895. Microinjection of salusin-β into the nucleus tractus solitarii inhibits cardiovascular function by suppressing presympathetic neurons in rostral ventrolateral medulla in rats
- Creator:
- Lu, Y., Wu, Y. S., Chen, D. S., Wang, M. M., Wang, W. Z., and Yuan, W. J.
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- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, neurony, physiology, neurons, salusin, medulla, baroreflex, presympathetic neuron, rat, 14, and 612
- Language:
- English
- Description:
- Salusin-β is newly identified bioactive peptide of 20 amino acids, which is widely distributed in hematopoietic system, endocrine system, and the central nervous system (CNS). Although salusin- β extensively expressed in the CNS, the central cardiovascular functions of salusin-β are unclear. Our main objective was to determine the cardiovascular effect of microinjection of salusin-β into the nucleus tractus solitarii (NTS) in anesthetized rats. Bilateral or unilateral microinjection of salusin-β (0.94-94 μg/rat) into the NTS dose-dependently decreased blood pressure and heart rate. Bilateral NTS microinjection of salusin-β (9.4 μg/rat) did not alter baroreflex sensitivity. Prior application of the glutamate receptor antagonist kynurenic acid (0.19 μg/rat, n=9) into the NTS did not alter the salusin-β (9.4 μg/rat) induced hypotension and bradycardia. However, pretreatment with the GABA receptor agonist muscimol (0.5 ng/rat) within the rostral ventrolateral medulla (RVLM) completely abolished the hypotension (-14±5 vs. -3±5 mm Hg, P <0.05) and bradycardia (-22±6 vs. -6±5 bpm, P <0.05) evoked by intra-NTS salusin-β (9.4 μg/rat). In addition, we found that vagotomy didn’t influence the actions of salusin-β (9.4 μg/rat) in the NTS. In conclusion, our present study shows that microinjection of salusin-β into the NTS significantly produces hypotension and bradycardia, presumably by suppressing the activities of presympathetic neurons in the RVLM., Y. Lu, Y. S. Wu, D. S. Chen, M. M. Wang, W. Z. Wang, W. J. Yuan., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
896. Microvascular endothelial cells from human omentum lack an inward rectifier K+ current
- Creator:
- Himmel, H. M., Rauen, U., and Ravens, U.
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- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, whole-cell voltage clamp, ion substitution, non-excitable cells, Na+ background current, chloride conductance, CA 2+ - activated K+ current, 14, and 612
- Language:
- English
- Description:
- In most macrovascular endothelial cell (EC) preparations, resting membrane potential is determined by the inwardly rectifying K+ current (IK1), whereas in microvascular EC the presence of IK1 varies markedly. Cultured microvascular EC from small vessels of human omentum were examined by means of the voltage-clamp technique to elucidate the putative role of IK1 in maintaining resting membrane potential. Macrovascular EC from human iliac artery and bovine aorta served as reference. Human omentum EC showed an outwardly rectifying current-voltage relation. Inward current was hardly sensitive to variations of extracellular [K+] and Ba2+ block suggesting lack of IK1. However, substitution of extracellular [Na+] and/or [Cl-] affected the current-voltage relation indicating that Na+ and Cl- contribute to basal current. Furthermore, outward current was reduced by tetraethylammonium (10 mM), and cell-attached recordings suggested the presence of a Ca2+-activated K+ current. In contrast to human omentum EC, EC from human iliac artery and bovine aorta possessed inwardly rectifying currents which were sensitive to variations of extracellular [K+] and blocked by Ba2+. Thus, the lack of IK1 in human omentum EC suggests that resting membrane potential is determined by Na+ and Cl- currents in addition to K+ outward currents., H. M. Himmel, U. Rauen, U. Ravens., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
897. Microvascular reactivity in patients with hypercholesterolemia: the effect of lipid lowering treatment
- Creator:
- Tomáš Štulc, Zdislava Kasalová, Martin Prázný, Michal Vrablík, Jan Škrha, and Richard Češka
- Format:
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- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, hypercholesterolémie, endoteliální dysfunkce, hypercholesterolemia, endothelial dysfunction, microcirculation, cholesterol lowering, laser-doppler, 14, and 612
- Language:
- English
- Description:
- Impaired NO-dependent vasodilation of resistance vessels is an early marker of an increased risk of atherosclerosis; utility of the examination of microcirculation, however, is far less established. We have therefore tested the hypothesis that hypercholesterolemia is associated with an impaired microvascular reactivity and that this defect is at least partially reversible by lipid-lowering treatment. Twenty-seven otherwise healthy patients with severe hypercholesterolemia (HLP) were examined at rest and then after 10 weeks of atorvastatin treatment (20 mg/day). Skin microvascular reactivity (MVR) was examined by laser-Doppler flowmetry. Baseline MVR values of the studied group were compared to healthy control subjects, HLP patients with coronary artery disease (CAD) and diabetic patients with and without diabetic retinopathy. MVR was normal in HLP subjects without CAD. On the contrary, MVR was impaired in HLP patients with CAD. There was no effect of atorvastatin on MVR, despite the profound reduction of serum lipids. MVR values did not correlate with cholesterol levels. In diabetic subjects, the MVR was substantially impaired only in patients with retinopathy. In the subjects without retinopathy, MVR was either normal (type I diabetes) or moderately impaired (type II diabetes). MVR was thus normal in HLP patients without manifest vascular disease and was not influenced by lipid lowering therapy. Impairment in the MVR was only evident in subjects with HLP and severe CAD. These results suggest that microcirculation is not involved in the early vascular dysfunction induced by HLP and that MVR rather reflects changes which appear later in the course of the atherosclerotic disease., T. Štulc, Z. Kasalová, M. Prázný, M. Vrablík, J. Škrha, R. Češka., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
898. Might Cardiac Catheterization Influence Diurnal Rhythm of the Steroid Stress Hormones Secretion?
- Creator:
- Hana Skarlandtová, Marie Bičíková, Petr Neužil, Mikuláš Mlček, Vladimír Hrachovina, Svoboda, T., Eva Medová, Kudlička, J., Alena Dohnalová, Štěpán Havránek, Hana Kazihnitková, Ludmila Máčová, Vařejková, E., and Otomar Kittnar
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie člověka, human physiology, Cortisol, Stress, Heart catheterization, Circadian rhythm, 14, and 612
- Language:
- English
- Description:
- Glucocorticoids (GCs) are steroid hormones produced by the adrenal cortex in reaction to stress stimuli. GCs production is not stable over a 24-hour period; the plasma concentration peaks in the morning (approximately upon awakening) and then the plasma levels decrease, reaching the nadir in the evening. In our experiments, the levels of cortisol, cortisone, DHEA and DHEAS were tested in young female pigs (n=23) during heart catheterization at two different day times (in the morning and in the afternoon). The non-parametric Mann-Whitney test for statistical analysis was used. We found only minimal statistical differences in studied markers between the morning and afternoon group (p>0.05). The absence of circadian variation in GCs levels could originate either at an early age of our experimental pigs, or in stressful conditions on the experiment day, or most likely the day before (e.g. social isolation, fasting, transport, and catheterization), respectively. We can conclude there is no difference in the stress load between morning and afternoon experiments, and therefore we can assume the stress load is not a limiting factor for the timing when catheterization should be preferably performed., H. Skarlandtová ... [et al.]., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
899. Mild hypothermia attenuates changes in respiratory system mechanics and modifies cytokine concentration in bronchoalveolar lavage fluid during low lung volume ventilation
- Creator:
- Dostál, P., Marian Šenkeřík, Radana Pařízková, Bareš, D., Pavel Živný, Helena Živná, and Černý, V.
- Format:
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- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, záněty, cytokiny, podchlazení organismu, inflammations, cytokines, hypothermia, rats, mechanical ventilation, 14, and 612
- Language:
- English
- Description:
- Hypothermia was shown to attenuate ventilator-induced lung injury due to large tidal volumes. It is unclear if the protective effect of hypothermia is maintained under less injurious mechanical ventilation in animals without previous lung injury. Tracheostomized rats were randomly allocated to non-ventilated group (group C) or ventilated grou ps of normothermia (group N) and mild hypothermia (group H). After two hours of mechanical ventilation with inspiratory fraction of oxygen 1.0, respiratory rate 60 min-1 , tidal volume 10 ml·kg-1 , positive end-expiratory pressure (PEEP) 2 cm H 2 O or immediately after tracheostomy in non-ventilated animals inspiratory pressures were recorded, rats were sacrificed, pressure-volume (PV) curve of respiratory system constructed, bronchoalveolar lavage (BAL) fluid and aortic blood samples obtained. Group N animals exhibited a higher rise in peak inspiratory pressures in comparison to group H animals. Shift of the PV curve to right, higher total protein and interleukin- 6 levels in BAL fluid were observed in normothermia animals in comparison with hypothermia animals and non-ventilated controls. Tumor necrosis factor- α was lower in the hypothermia group in comparison with normothermia and non-ventilated groups. Mild hypothermia attenuated changes in respiratory system mechanics and modified cytokine concentration in bronchoalveolar lavage fluid during low lung volume ventilation in animals without previous lung injury., P. Dostál, M. Šenkeřík, R. Pařízková, D. Bareš, P. Živný, H. Živná, V. Černý., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
900. Miotic action of tramadol is determined by CYP2D6 genotype
- Creator:
- Ondřej Slanař, Milan Nobilis, Jaroslav Květina, Rudolf Mikoviny, Tomáš Zima, Jeffrey R. Idle, and František Perlík
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Farmacie. Farmakologie, farmakokinetika, cytochromy, genotyp, pharmacokinetics, cytochromes, genotype, cytochrom P450 2D6, miosa, tramadol, cytochrome P450 2D6, miosis, 14, and 615
- Language:
- English
- Description:
- Polymorphic CYP2D6 is the enzyme that activates the opioid analgesic tramadol by O-demethylation to its active metabolite O-demethyltramadol (M1). Our objective was to determine the opioid effects measured by pupillary response to tramadol of CYP2D6 genotyped volunteers in relation to the disposition of tramadol and M1 in plasma. Tramadol displayed phenotypic pharmacokinetics and it was possible to identify poor metabolizers (PM) with >99 % confidence from the metabolic ratio (MR) in a single blood sample taken between 2.5 and 24 h post-dose. Homozygous extensive metabolizers (EM) differed from PM subjects by an almost threefold greater (P=0.0014) maximal pupillary constriction (Emax). Significant correlations between the AUC and Cmax values of M1 versus pupillary constriction were found. The corresponding correlations of pharmacokinetic parameters for tramadol itself were weaker and negative. The strongest correlations were for the single-point metabolic ratios at all sampling intervals versus the effects, with rs ranging from 0.85 to 0.89 (p‹0.01). It is concluded that the concept of dual opioid/non-opioid action of the drug, though considerably stronger in EMs, is valid for both EM and PM subjects. This is the theoretical basis for the frequent use and satisfactory efficacy of tramadol in clinical practice when given to genetically non-selected population., O. Slanař, M. Nobilis, J. Květina, R. Mikoviny, T. Zima, J. R. Idle, F. Perlík., and Obsahuje biblografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public