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1102. Pheochromocytoma and markers of oxidative stress
- Creator:
- Turková, H., Ondřej Petrák, Jan Škrha, Jiří Widimský, and Tomáš Zelinka
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie člověka, human physiology, pheochromocytoma, catecholamines, oxidative stress, 14, and 612
- Language:
- English
- Description:
- High levels of catecholamines in pheochromocytoma (PHEO) are associated with risk of cardiovascular complications. In this study, we looked for potential differences in markers of oxidative stress – vitamin C, superoxide dismutase (SOD) and malondialdehyde (MDA) in PHEO before and after the operation. We studied 18 subjects with PHEO who were examined before and approximately one year after the successful tumor removal (free of disease). All subjects had elevated urinary epinephrine and/or norepinephrine levels before the operation. Vitamin C levels increased significantly after the operation from 61±27 to 77±20 μmol/l (P=0.02), and MDA decreased significantly after the tumor removal from 2.6±0.4 to 2.0±0.6 μmol/l (P=0.01). However, no changes were found in SOD activity before and after the operation. In conclusion, increased catecholamine production in PHEO is accompanied by decreased levels of vitamin C and increased levels of MDA which may indicate the activation of oxidative stress in PHEO. Successful operation was associated with lowering of oxidative stress by using both biomarkers. On the contrary, no changes in SOD activity before and after the tumor removal were noted., H. Turková, ... [et al.]., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1103. Phosphodiesterases inhibition enhances the effect of glucagon on cardiac automaticity in the isolated right ventricle of the rat
- Creator:
- Gonzalez-Muñoz, C. and Hernández, J.
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, glukagon, glucagon, cyclic nucleotide phosphodiesterases (PDE), cardiac automaticity, isoproterenol, 14, and 612
- Language:
- English
- Description:
- We evaluated the effect of glucagon on cardiac automaticity as well as the possible role of cyclic nucleotide phosphodiesterases (PDE) in regulating this effect. Concentration response curves for glucagon in the absence and in th e presence of the non-selective PDE inhibitor IBMX were performed in the isolated right ventricle of the rat. We found that glucagon produces only a minor increase of ventricular automa ticity (11.0±4.1, n=5) when compared to the full agonist of β-adrenoceptor isoproterenol (182.2±25.3, n=7). However, IBMX enhances the maximal efficacy of glucagon on cardiac automaticity (11.0±4.1, in the absence and 45.3±3.2 in the presence of IBMX, n=5, P<0.05). These results indicate that PDE blunts proarrhythmic effects of glucagon in rat myocardium., C. Gonzalez-Muñoz, J. Hernández., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1104. Phospholemman does not participate in forskolin-induced swine carotid artery relaxation
- Creator:
- Meeks, M. K., Han, S., Tucker, Amy L., and Rembold, Christopher M.
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, kardiovaskulární fyziologie, hladké svaly, bílkoviny, cardiovascular physiology, smooth muscles, proteins, cyclic AMP (adenosine monophosphate), FXYD protein, HSP20, myosin light chain, vascular smooth muscle, 14, and 612
- Language:
- English
- Description:
- Phosphorylation of phospholemman (PLM) on ser68 has been proposed to at least partially mediate cyclic AMP (cAMP) mediated relaxation of arterial smooth muscle. We evaluated the time course of the phosphorylation of phospholemman (PLM) on ser68, myosin regulatory light chains (MRLC) on ser19, and heat shock protein 20 (HSP20) on ser16 during a transient forskolin-induced relaxation of histamine-stimulated swine carotid artery. We also evaluated the dose response for forskolin- and nitroglycerin-induced relaxation in phenylephrine-stimulated PLM-/- and PLM+/+ mice. The time course for changes in ser19 MRLC dephosphorylation and ser16 HSP20 phosphorylation was appropriate to explain the forskolin-induced relaxation and the recontraction observed upon washout of forskolin. However, the time course for changes in ser68 PLM phosphorylation was too slow to explain forskolin-induced changes in force. There was no difference in the phenylephrine contractile dose response or in forskolin-induced relaxation dose response observed in PLM-/- and PLM+/+ aortae. In aortae precontracted with phenylephrine, nitroglycerin induced a slightly, but significantly greater relaxation in PLM-/- compared to PLM+/+ aortae. These data are consistent with the hypothesis that ser19 MRLC dephosphorylation and ser16 HSP20 phosphorylation are involved in forskolin-induced relaxation. Our data sugge st that PLM phosphorylation is not significantly involved in forskolin-induced arterial relaxation., M. K. Meeks, S. Han, A, L. Tucker, C. M. Rembold., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1105. Physical exercise-induced cardiovascular adjustments are modulated by muscarinic cholinoceptors within the ventromedial hypothalamic nucleus
- Creator:
- Wanner, S. P., Guimarães, J. B., Pires, W., La Guardia, R. B., Haibara, A. S., Marubayashi, U., Coimbra, C. C., and Lima, N. R. V.
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, acetylcholin, únava, acetylcholine, fatigue, hypothalamus, methylatropine, 14, and 612
- Language:
- English
- Description:
- The effects of blocking ventromedial hypothalamic nucleus (VMH) muscarinic cholinoceptors on cardiovascular responses were investigated in running rats. Animals were anesthetized with pentobarbital sodium and fitted with bilateral cannulae into the VMH. After recovering from surgery, the rats were familiarized to running on a treadmill. The animals then had a polyethylene catheter implanted into the left carotid artery to measure blood pressure. Tail skin temperature (Ttail), heart rate, and systolic, diastolic and mean arterial pressure were measured after bilateral injections of 0.2 μl of 5 × 10−9 mol methylatropine or 0.15 M NaCl solution into the hypothalamus. Cholinergic blockade of the VMH reduced time to fatigue by 31% and modified the temporal profile of cardiovascular and Ttail adjustments without altering their maximal responses. Mean arterial pressure peak was achieved earlier in methylatropine-treated rats, which also showed a 2-min delay in induction of tail skin vasodilation, suggesting a higher sympathetic tonus to peripheral vessels. In conclusion, muscarinic cholinoceptors within the VMH are involved in a neuronal pathway that controls exercise-induced cardiovascular adjustments. Furthermore, blocking of cholinergic transmission increases sympathetic outflow during the initial minutes of exercise, and this higher sympathetic activity may be responsible for the decreased performance., S. P. Wanner ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1106. Physiological response to whole-body vibration in athletes and sedentary subjects
- Creator:
- Gojanovic, B., Feihl, F., Gremion, G., and Waeber, B.
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, tělesná cvičení, srdeční rytmus, vibrace, exercises, heart rate, vibration, oxygen consumption, sedentary lifestyle, 14, and 612
- Language:
- English
- Description:
- Whole-body vibration (WBV) is a new exercise method, with good acceptance among sedentary subjects. The metabolic response to WBV has not been well documented. Three groups of male subjects, inactive (SED), endurance (END) and strength trained (SPRINT) underwent a session of side-alternating WBV composed of three 3-min exercises (isometric half-squat, dynamic squat, dynamic squat with added load), and repeated at three frequencies (20, 26 and 32 Hz). VO2, heart rate and Borg scale were monitored. Twenty-seven healthy young subjects (10 SED, 8 SPRINT and 9 END) were included. When expressed in % of their maximal value recorded in a treadmill test, both the peak oxygen consumption (VO2) and heart rate (HR) attained during WBV were greatest in the SED, compared to the other two groups (VO2: 59.3 % in SED vs 50.8 % in SPRINT and 48.0 % in END, p<0.01; HR 82.7 % in SED vs 80.4 % in SPRINT and 72.4 % in END, p<0.05). In conclusions, the heart rate and metabolic response to WBV differs according to fitness level and type, exercise type and vibration frequency. In SED, WBV can elicit sufficient cardiovascular response to benefit overall fitness and thus be a potentially useful modality for the reduction of cardiovascular risk., B. Gojanovic, F. Feihl, G. Gremion, B. Waeber., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1107. Physiological role of FGF signaling in growth and remodeling of developing cardiovascular system
- Creator:
- Krejci, E., Živorad Peševski, Ondřej Naňka, and David Sedmera
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, chick embryo, vasculogenesis, myocyte proliferation, conotruncal banding, 14, and 612
- Language:
- English
- Description:
- Fibroblast growth factor (FGF) signaling plays an important role during embryonic induction and patterning, as well as in modulating proliferative and hypertrophic growth in fetal and adult organs. Hemodynamically induced stretching is a powerful physiological stimulus for embryonic myocyte proliferation. The aim of this study was to assess the effect of FGF2 signaling on growth and vascularization of chick embryonic ventricular wall and its involvement in transmission of mechanical stretchinduced signaling to myocyte growth in vivo . Myocyte proliferation was significantly higher at the 48 h sampling interval in pressure-overloaded hearts. Neither Western blotting, nor immunohistochemistry performed on serial paraffin sections revealed any changes in the amount of myocardial FGF2 at that time point. ELISA showed a significant increase of FGF2 in the serum. Increased amount of FGF2 mRNA in the heart was confirmed by real time PCR. Blocking of FGF signaling by SU5402 led to decreased myocyte proliferation, hemorrhages in the areas of developing vasculature in epicardium and digit tips. FGF2 synthesis is increased in embryonic ventricular cardiomyocytes in response to increased stretch due to pressure overload. Inhibition of FGF signaling impacts also vasculogenesis, pointing to partial functional redundancy in paracrine control of cell proliferation in the developing heart., E. Krejci, Z. Pesevski, O. Nanka, D. Sedmera., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1108. Physiology of nitric oxide in the respiratory system
- Creator:
- Antošová, M., Daniela Mokrá, Pepucha, L., Jana Plevková, Buday, T., Sterusky, M., and Alica Benčová
- Format:
- print, bez média, and svazek
- Type:
- article, články, journal articles, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, oxid dusnatý, fyziologie, nitric oxide, physiology, nitric oxide synthase, respiratory system, 14, and 612
- Language:
- English
- Description:
- Nitric oxide (NO) is an important endogenous neurotransmitter and mediator. It participates in regulation of physiological processes in different organ systems including airways. Therefore, it is important to clarify its role in the regulation of both airway and vascular smooth muscle, neurotransmission and neurotoxicity, mucus transport, lung development and in the surfactant production. The bioactivity of NO is highly variable and depends on many factors: the presence and activity of NO-producing enzymes, activity of competitive enzymes (e.g. arginase), the amount of substrate for the NO production, the presence of reactive oxygen species and others. All of these can change NO primary physiological role into potentially harmful. The borderline between them is very fragile and in many cases not entirely clear. For this reason, the research focuses on a comprehensive understanding of NO synthesis and its metabolic pathways, genetic polymorphisms of NO synthesizing enzymes and related effects. Research is also motivated by frequent use of exhaled NO monitoring in the clinical manifestations of respiratory diseases. The review focuses on the latest knowledge about the production and function of this mediator and understanding the basic physiological processes in the airways., M. Antosova, D. Mokra, L. Pepucha, J. Plevkova, T. Buday, M. Sterusky, A. Bencova., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1109. Pig model of pulmonary embolism: where is the hemodynamic break point?
- Creator:
- Kudlička, J., Mikuláš Mlček, Hála, P., Lacko, S., Janák, D., Hrachovina, M., Jan Malík, Jan Bělohlávek, Petr Neužil, and Otomar Kittnar
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, plicní embolie, hemodynamika, šok (lékařství), pulmonary embolism, hemodynamics, shock (medicine), pig model, 14, and 612
- Language:
- English
- Description:
- Early recognition of collapsing hemodynamics in pulmonary embolism is necessary to avoid cardiac arrest using aggressive medical therapy or mechanical cardiac support. The aim of the study was to identify the maximal acute hemodynamic compensatory steady state. Overall, 40 dynamic obstructions of pulmonary artery were performe d and hemodynamic data were collected. Occlusion of only left or right pulmonary artery did not lead to the hemodynamic collapse. When gradually obstructing the bifurcation, the right ventri cle end-diastolic area expanded proportionally to pulmonary artery mean pressure from 11.6 (10.1, 14.1) to 17.8 (16.1, 18.8) cm 2 (p<0.0001) and pulmonary artery mean pressure increased from 22 (20, 24) to 44 (41, 47) mmHg (p<0.0001) at the poin t of maximal hemodynamic compensatory steady state. Sim ilarly, mean arte rial pressure decreased from 96 (87, 101) to 60 (53, 78) mmHg (p<0.0001), central venous pressure increased from 4 (4, 5) to 7 (6, 8) mmHg (p<0.0001), heart rate increased from 92 (88, 97) to 147 (122, 165) /min (p<0.0001), contin uous cardiac output dropped from 5.2 (4.7, 5.8) to 4.3 (3.7, 5.0) l/min (p=0.0023), modified shock index increased from 0.99 (0.81, 1.10) to 2.31 (1.99, 2.72), p<0.0001. In conclusion, in stead of continuous cardiac output all of the analyzed parameters can sensitively determine the individual maximal compensatory response to obstructive shock. We assume their monitoring can be used to predict the critical phase of the hemodynamic status in routine practice., J. Kudlička ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1110. Place avoidance tasks as tools in the behavioral neuroscience of learning and memory
- Creator:
- Aleš Stuchlík, Tomáš Petrásek, Prokopová, I., Holubová, K., Hatalová, H., Karel Valeš, Kubík, Š., Dockery, C., and Wesierska, M.
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, navigace, učení, paměť, navigation, learning, memory, spatial learning, cognitive coordination, orientation, place avoidance, lesions, neuropharmacology, behavioral tasks, 14, and 612
- Language:
- English
- Description:
- Spatial navigation comprises a widely-studied complex of animal behaviors. Its study offers many methodological advantages over other approaches, enabling assessment of a variety of experimental questions and the possibility to compare the results across different species. Spatial navigation in laboratory animals is often considered a model of higher human cognitive functions including declarative memory. Almost fifteen years ago, a novel dry-arena task for rodents was designed in our laboratory, originally named the place avoidance task, and later a modification of this approach was established and called active place avoidance task. It employs a continuously rotating arena, upon which animals are trained to avoid a stable sector defined according to room-frame coordina tes. This review describes the development of the place avoidance tasks, evaluates the cognitive processes associated with performance and explores the application of place avoidance in the testing of spatial learning after neuropharmacological, lesion and other experimental manipulations., A. Stuchlík ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public