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302. Permanent depression of plasma cGMP during long-term space flight
- Creator:
- Rössler, A., Noskov, V., László, Z., Polyakow, V. V., and Helmut Hinghofer-Szalkay
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, Long-duration space flight, head-down tilt, cyclic guanosine monophosphate, atrial natriuretic peptide, bed rest, 14, and 612
- Language:
- English
- Description:
- The purpose of this study was to investigate plasma concentrations of cyclic guanosine monophosphate (cGMP) and atrial natriuretic peptide (ANP) during and after real and simulated space flight. Venous blood was obtained 3 min after the beginning and 2 min after the lower body negative pressure maneuver in two cosmonauts preflight (supine), inflight, and postflight (supine) and in five other subjects before, at the end, and 4 days after a 5-day head-down tilt (-6°) bed rest. In cosmonaut 1 (10 days in space), plasma cGMP fell from preflight 4.3 to 1.4 nM on flight day 6, and was 3.0 nM on the fourth day after landing. In cosmonaut 2 (438 days in space), it fell from preflight 4.9 to 0.5 nM on on flight day 3, and stayed <0.1 nM with 5, 9, and 14 months in space, as well as on the fourth day after landing. Three months after the flight his plasma cGMP was back to normal (6.3 nM). Cosmonaut 2 also displayed relatively low inflight ANP values but returned to preflight level immediately after landing. In a ground-based simulation on five other persons, supine plasma cGMP was reduced by an average of 30 % within 5 days of 6° head-down tilt bed rest. The data consistently demonstrate lowered plasma cGMP with real and simulated weightlessness, and a complete disappearance of cGMP from plasma during, and shortly after long-duration space flight., A. Rössler, V. Noskov, Z. László, V.V. Polyakow, H. G. Hinghofer-Szalkay., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
303. Peroxidative damage of mitochondrial respiration is substrate-dependent
- Creator:
- Endlicher, R., Pavla Křiváková, Hana Rauchová, Hana Nůsková, Zuzana Červinková, and Zdeněk Drahota
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, mitochondrie, physiology, mitochondrias, liver mitochondria, mitochondrial enzymes, peroxidative damage, tert-butyl hydroperoxide, 14, and 612
- Language:
- English
- Description:
- The concentration-dependence of tert-butyl hydroperoxide (BHP) inhibitory effect on oxygen consumption in isolated rat liver mitochondria was measured in the presence of various respiratory substrates. Strong inhibitory effect at low concentrations of BHP (15-30 μM) was found for oxoglutarate and palmitoyl carnitine oxidation. Pyruvate and glutamate oxidation was inhibited at higher concentrations of BHP (100-200 μM). Succinate oxidation was not affected even at 3.3 mM BHP. Determination of mitochondrial membrane potential has shown that in the presence of NADH-dependent substrates the membrane potential was dissipated by BHP but was completely restored after addition of succinate. Our data thus indicate that beside peroxidative damage of complex I also various mitochondrial NADH-dependent dehydrogenases are inhibited, but to a different extent and with different kinetics. Our data also show that succinate could be an important nutritional substrate protecting hepatocytes during peroxidative damage., R. Endlicher ... [et al.]., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
304. Peroxisome proliferator-activated receptor γ in white and brown adipocyte regulation and differentiation
- Creator:
- Wu, Hui, Li, Xiaohua, and Shen, Chunyan
- Format:
- počítač and online zdroj
- Type:
- model:article and TEXT
- Subject:
- fyziologie, physiology, differentiation regulation, PPARγ, adipocytes, white adipose tissue, brown adipose tissue, 14, and 612
- Language:
- English
- Description:
- In as early as 1997, the World Health Organization officially recognized obesity as a chronic disease. The current epidemic of obesity and overweightness has aroused great interest in the study of adipose tissue formation. The transcription factor peroxisome proliferator-activated receptor γ (PPARγ) binds to the target gene promoter regulatory sequences, acting as a key factor in regulating the differentiation of preadipocytes in the adipose tissue, and plays an important role in regulating the adipocyte metabolism. A further understanding of the structure and expression characteristics of PPARγ, in addition to its mechanisms of action in adipocyte differentiation, may be applied to control obesity and prevent obesity-related diseases. In this article, recent studies investigating the effect of regulating PPARγ on adipocyte differentiation are reviewed. In particular, the structural characteristics, expression patterns, and molecular mechanisms of PPARγ function in adipocyte differentiation are considered., Hui Wu, Xiaohua Li, Chunyan Shen., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
305. PhD student workshop (June 2-4, 2008, Seč, Czech Republic)
- Format:
- print, bez média, and svazek
- Type:
- article, abstrakta, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, Fyziologický ústav (Akademie věd ČR), fyziologie, studentská odborná činnost, workshopy, physiology, student professional activities, workshops, 14, and 612
- Language:
- English
- Description:
- Obsahuje 44 abstrakt
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
306. Photosynthetic, physiological and biochemical events associated with polyethylene glycol-mediated osmotic stress tolerance in taro (Colocasia esculenta L. Schott)
- Creator:
- Sahoo, M. R., Dasgupta, M., Kole, P. C., and Mukherjee, A.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, fyziologie, kolokázie jedlá, photosynthesis, physiology, taro, antioxidative enzymes, osmotic stress, polyethylene glycol, 2, and 581
- Language:
- Multiple languages
- Description:
- Six genotypes of taro (Colocasia esculenta L. Schott) were evaluated under in vitro and in vivo polyethylene glycol (PEG-6000)-mediated osmotic stress conditions. A significant variation in growth response was observed among the taro genotypes under in vitro-induced stress conditions. In vivo results indicated a significant effect of osmotic stress on photosynthetic parameters, such as net photosynthetic rate, transpiration rate, stomatal conductance, stomatal resistance, internal CO2 concentration, carboxylation efficiency, and transpiration efficiency on the tested genotypes at the tuberization stage. Lesser variations in photosynthesis and higher accumulation of proline, phenols, and antioxidative enzymes, namely, superoxide dismutase and guaiacol peroxidase, were associated with yield maintenance under osmotic stress conditions. The genotypes DP-89, IGCOL-4, and Ramhipur showed a higher degree of tolerance towards osmotic stress with a minimum variation in the studied parameters. These genotypes could be lines of interest for intensification of breeding strategies to develop drought-tolerant plants., M. R. Sahoo, M. Dasgupta, P. C. Kole, A. Mukherjee., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
307. 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
308. 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
309. Plasma dependent and independent accumulation of betaine in male and female rat tissues
- Creator:
- Slow, S., Lever, M., Chambers, S. T., and George, P. M.
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, betaine, osmolyte, methyl donor, tissue content, rats, 14, and 612
- Language:
- English
- Description:
- Tissue betaine is an intracellular osmolyte that also provides a store of labile methyl groups. Despite these important biological roles, there are few data regarding tissue betaine content. We measured the betaine concentration of plasma and various tissues (brain, heart, lungs, liv er, kidney, spleen, intestine, reproductive tissues, skeletal muscle and skin) in male and female rats and assessed whether there were any gender-specific differences in betaine content or distribution and whether there was any relationship between tissue accumulation and plasma levels. Betaine was highest in the liver and kidney with values ranging from 1.6 to 9.5 mmol/l and 2.0 to 5.4 mmol/l, respectively. Plasma betaine concentrations were significantly lower than tissue levels except in the brain ( ≈ 25 % of plasma) and skeletal muscle (similar to pl asma). Regression analysis of the combined male and female data revealed a significant plasma-related accumulation of betaine in the heart, skin and skeletal muscle, while the lung, liver, kidney, spleen, and intestine showed significant plasma-related and plasma- independent accumulations of be taine. The betaine content of the skin, liver and kidney was no t significantly different between males and females, but in plasma and all tissues analyzed it was significantly higher in males (P<0.01)., S. Slow, M. Lever, S. T. Chambers, P. M. George., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
310. Plasma levels of dosulepine and heart electric field
- Creator:
- Eva Kitzlerová, Jaroslav Slavíček, Klára Semerádová, Martin Anders, Alena Dohnalová, and Marie Balíková
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, cardiotoxicity, dosulepine, plasma levels, ECG, heart electric field, 14, and 612
- Language:
- English
- Description:
- Antidepressants, particularly tricyclic (TCA) antidepressants, may have cardiotoxic effects, such as cardiac arrhythmias, especially in patients with cardiovascular diseases. For most of TCA, no exact correlation between dosage, plasma levels and changes of ECG parameters of standard ECG has been found. So far, no relationship between dosulepine plasma levels and heart electric field parameters has been studied. We selected 18 female outpatient subjects diagnosed with recurrent depressive disorders, currently in the remission phase (HAMD < 10), without any cardiovascular disease. Patients were treated with daily dosulepine doses of 25-125 mg for 4-8 weeks. 30 heart electric field parameters were analyzed by Cardiag 128.1 diagnostic system as part of BSPM (Body Surface Potential Mapping). Acquired data were correlated with dosulepine plasma levels by means of Spearmanís rank order correlation test. Four ECG parameters showed a significant correlation with dosulepine plasma levels: QRS axis deviation in frontal plane (p=0.01), DIAM 40 max (p < 0.05), QRS-STT angle in transversal and left sagittal plane (p < 0.05). The demonstrated changes confirmed dosulepine influence on the early myocardium depolarization phase and the correlation of this effect with dosulepine dose (its plasma concentration). The higher the dosulepine level, the more marked are the changes of the QRS-STT angle in transversal and sagittal planes and the changes in the QRS axis deviation in frontal plane. Repeatedly recorded changes in the heart electric field were dosulepine-specific and dependent on its plasma levels., E. Kitzlerová, I. Paclt, J. Slavíček, K. Pišvejcová, M. Anders, A. Dohnalová, M. Balíková., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public