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5492. Effect of hindlimb unweighting on expression of hypoxia-inducible factor-1α, vascular endothelial growth factor, angiopoietin, and their receptors in mouse skeletal muscle
- Creator:
- Wagatsuma, A.
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Biochemie. Molekulární biologie. Biofyzika, fyziologie, končetiny, svalová atrofie, physiology, extremities, muscular atrophy, anigiogenic factor, capillary regression, hindlimb unweighting, 2, and 577
- Language:
- English
- Description:
- Hindlimb unweighting (HU) leads to capillary regression in skeletal muscle. However, the molecular mechanism(s) remains to be elucidated. To gain insight into the regulation of this process, we investigated gene expression of hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor (VEGF), angiopoietin, and their receptors in the atrophied muscle induced by HU. The hindlimbs of mice were unweighted by tail-suspension and then the gastrocnemius muscles were isolated after 10 days. To assess the capillary distribution, the capillary endothelium in frozen transverse sections was identified by staining for alkaline phosphatase. The mRNA levels were analyzed using a real-time reverse transcription-polymerase chain reaction. After 10 days of HU, the number of capillaries around a muscle fiber was significantly decreased by 19.5 %, suggesting that capillary regression appears to occur. The expression of HIF-1α was significantly down-regulated after 10 days of HU. The expression of VEGF remained unchanged, whereas those of Flt-1, KDR/Flk-1, and neuropilin-1 were significantly down-regulated, suggesting that VEGF signaling through these receptors would be attenuated. The expression of angiopoietin-1, and -2, as well as their receptor, Tie-2 were also significantly down-regulated, suggesting that angiopoietin-1 signaling through Tie-2 would be attenuated. These findings suggest that alterations in expression of VEGF, angiopoietins, and their receptors may be associated with capillary regression after HU., A. Wagatsuma., and Obsahuje biblografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5493. Effect of homocysteine on survival of human glial cells
- Creator:
- Škovierová, H., Mahmood, S., Blahovcová, E., Jozef Hatok, Ján Lehotský, and Murín, R.
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, homocystein, hyperhomocysteinémie, buněčná smrt, neurodegenerace, cell death, homocysteine, hyperhomocysteinemia, neurodegeneration, glioblastoma, gliotoxicity, 14, and 612
- Language:
- English
- Description:
- Several neurodegenerative conditions, such as Alzheimer’s disease and Parkinson’s disease, or vascular dementia and cognitive impairment, are associated with mild hyperhomocysteinemia. Hyperhomocysteinemia is defined as an increas e of the homocysteine (Hcy) level beyond 10 μM. Although the adverse effect of Hcy on neurons is well documented, knowledge about the impact of this amino acid on glial cells is missing. Therefore, with the aim to evaluate the neurotoxic properties of Hcy on glial cells, we used a glioblastoma cell line as a study model. The viability of cells was assayed biochemically and cytologically. At a concentration around 50 μM in the culture medium D,L -Hcy induced cell death. It is noteworthy that Hcy induces cell death of human glial cells at concentrations encountered during mild hyperhomocysteinemia. Therefore, we propose that Hcy -induced impairment of neuronal functions along with damage of glial cells may contribute to the etiopathogenesis of neurodegenerative diseases associated with hyperhomocysteinemia., H. Škovierová, S. Mahmood, E. Blahovcová, J. Hatok, J. Lehotský, R. Murín., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5494. Effect of host plant on body size of Frankliniella occidentalis (Thysanoptera: Thripidae) and its correlation with reproductive capacity
- Creator:
- Kogel, Willem Jan de, Bosco, Domenico, Hoek, Marieke van der, and Mollema, Chris
- Format:
- print, text, and regular print
- Type:
- article, bibliography, model:article, and TEXT
- Subject:
- zoologie, entomologie, hmyz, Thysanoptera, Thripidae, Frankliniella occidentalis, rozmnožování, velikost těla, potrava, hostitelská rostlina, vzájemné vztahy, 595.2/.7, and 591.5
- Language:
- English
- Description:
- The effect of different host plants on Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) body size was investigated. Thrips from three different populations, from the Netherlands, Italy, and USA, achieved greater body sizes when reared on cucumber than on bean. The same thrips grew larger when reared on susceptible than on resistant cucumber. On the latter, reproduction was reduced, suggesting that smaller thrips have a lower reproduction. However, no evidence was found for a correlation between size and reproduction in experiments with thrips from four different populations, from the Netherlands, New Zealand, France, and USA that differed significantly in body size. Also when individual thrips from the four populations were tested, there was no correlation between size and reproduction. It is concluded that resistant cucumber affects both size and reproduction of F. occidentalis. However, lower reproduction in general is not associated with smaller body size., Willem Jan de Kogel, Domenico Bosco, Marieke van der Hoek, Chris Mollema, and Lit
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
5495. Effect of Hypothermia on Insulin - Receptor Interaction in Different Rat Tissues
- Creator:
- Torlinska, T., Perz, M., Madry, E., Hryniewiecki, T., Nowak, K. W., and Philip A. Mackowiak
- Format:
- print, bez média, and svazek
- Type:
- article, studie, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie člověka, human physiology, Hypothermia, Insulin receptors, Liver, Adipose tissue, Skeletal muscle, Heart, Brain, 14, and 612
- Language:
- English
- Description:
- Experimental hypothermia caused extensive changes in the number of both classes of insulin receptors in different rat tissues. In the liver, the number of high affinity insulin receptors (HAIRs) decreased by 50 % (from 25.3 to 12.6 fmol/mg membrane protein), whereas number of low affinity insulin receptors (LAIRs) was almost unchanged in comparison to normothermic animals (5.63 and 4.39 pmol/mg, respectively). In the adipose tissue, number of both classes was reduced - HAIRs by 81 % (from 24.0 to 4.50 fmol/mg) and LAIRs by 92 % (from 16.0 to 1.29 pmol/mg). In the skeletal muscle, capacity of HAIRs was not changed (16.2 and 19.3 fmol/mg in normo- and hypothermic animals, respectively), whereas number of LAIRs increased by 150 % (from 6.65 to 16.6 pmol/mg). Hypothermic rats also showed lower amount (by 85 %) of LAIRs in the heart muscle (9.37 and 1.43 pmol/mg in control and experimental animals, respectively). Simultaneously, no significant changes were found in HAIRs (16.3 and 11.9 fmol/mg, respectively) and LAIRs (4.43 and 3.88 pmol/mg, respectively) in the brain. These differences in insulin receptors responses to hypothermia may reflect different physiological role of insulin in the regulation of target cell metabolism and/or the differences in tissue distribution of the insulin receptor isoforms., T. Torlinska, M. Perz, E. Madry, T. Hryniewiecki, K. W. Nowak, P. Mackowiak., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5496. Effect of imazapic residues on photosynthetic traits and chlorophyll fluorescence of maize seedlings
- Creator:
- Su, W. C., Sun, L. L., Wu, R. H., Ma, Y. H., Wang, H. L., Xu, H. L., Yan, Z. L., and Lu, C. T.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fluorescence chlorofylu, výměna plynu, růstové charakteristiky, fotosystém II, chlorophyll fluorescence, gas exchange, growth characteristics, photosystem II, 2, and 581
- Language:
- Multiple languages
- Description:
- The influence of various concentrations of imazapic residues (0-800 μg kg-1) on the growth, chlorophyll content, and photosynthetic characteristics of maize seedlings was studied in a greenhouse pot experiment. Plant height, root length, shoot dry mass, root dry mass, and total dry mass of maize declined with the increase of imazapic residue concentrations. The root/shoot ratio initially decreased and then increased in presence of imazapic, which indicated that the effects of imazapic residues on plant height and root length might differ in maize seedlings. Lowered chlorophyll content and net photosynthetic rate were observed in leaves of maize seedlings in all treatments and indicated a dose-response relationship to imazapic concentrations. Intercellular carbon dioxide concentration, transpiration rate, and stomatal conductance also declined to varying extents, but the chlorophyll a/b ratio increased gradually together with the increase of imazapic residue concentrations. Generally, the maize seedlings were negatively affected by the imazapic residues in soil. Response of root length and biomass to imazapic residues could be the important index for maize variety selection., W. C. Su, L. L. Sun, R. H. Wu, Y. H. Ma, H. L. Wang, H. L. Xu, Z. L. Yan, C. T. Lu., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5497. Effect of in ovo leptin administration on development of Japanese quails
- Creator:
- Dalma Lamošová, Máčajová, M., Michal Zeman, Mózeš, Š., and Daniela Ježová
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- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, leptin, hormony, hormones, Japanese quail, in ovo manipulation, postembryonic development, 14, and 612
- Language:
- English
- Description:
- Potential changes in the activity of endocrine axes related to growth as a result of leptin administration during embryonic development of birds were evaluated in the Japanese quail as a model bird with fast growth and development. On day 5 of incubation, 0.1 µg or 1 µg of recombinant mice leptin in 50 µl of phosphate buffered saline were injected into the albumen of eggs. Animals from each group were killed by decapitation on day 0, 2, 5, 7, 14, 21, 28, 35, 42, 49 and 56 of life. Plasma concentrations of triiodothyronine (T3), thyroxin (T4), corticosterone, testosterone, total lipids, triacylglycerols, cholesterol, glucose and alkaline phosphatase activity were measured. Quail treated by leptin hatched earlier (5-24 hours) and had a higher body weight than the control group (P<0.05-0.001). Mean body weight across the whole observed period was higher in both treated groups as compared to the control group (P<0.05). Leptin in ovo administration was accompanied by changes of endocrine and metabolic parameters during postembryonic development. The most prominent changes appeared immediately after hatching (T3, T4, total lipids, triacylglycerols) and before sexual maturity. It is suggested that leptin acts as a general signal of low energy status to neuroendocrine systems in birds which improves utilization of nutrients., D. Lamošová, M. Máčajová, M. Zeman, Š. Mózeš, D. Ježová., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5498. Effect of indomethacin and deendothelisation on vascular responses in the renal artery
- Creator:
- Viera Kristová, Milan Kriška, Vojtko, R., and Kurtanský, A.
- Format:
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- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, renal artery, vasoconstrictor responses, indomethacin, deendothelisation, 14, and 612
- Language:
- English
- Description:
- Vasodilator prostaglandins (PGE2, PGI2) play an important role in the regulation of renal blood flow. Hence, inhibition of their production with nonsteroidal anti-inflammatory drugs increases renal vascular resistance and exerts adverse renal effects. It has been reported that besides endothelium-derived prostaglandin products, nitric oxide (NO) may be mainly involved in regulation of renal functions. The aim of our study was to evaluate the effect of cyclooxygenase inhibition with indomethacin and endothelium removal on vascular responses of the renal artery as a model vessel. Isolated segments of rabbit renal arteries were perfused at constant flow. Indomethacin administration (10-5mol.l-1) significantly increased the responses to single doses (0.1, 1, 10 m g) of noradrenaline (NA) as compared with the controls. In indomethacin-pretreated vessels, subsequent deendothelisation by air bubbles enhanced the constrictor responses to NA. In reversed order, when deendothelisation was followed by indomethacin administration, the responses to NA were similar in character. A comparison of renal artery responses to NA in both experimental situations did not reveal any significant differences. It can be supposed that endothelial and non-endothelial factors may be involved in local regulation of renal vascular tone., V. Kristová, M. Kriška, R. Vojtko, A. Kurtanský., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5499. Effect of intermittent high altitude hypoxia on gene expression in rat heart and lung
- Creator:
- Deindl, E., František Kolář, Neubauer, E., Vogel, S., Wolfgang Schaper, and Bohuslav Ošťádal
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- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, hypoxie, hypoxia, hypoxia regulated genes, transforming growth factor-β, vascular endothelial growth factor, c-jun, c-fos, 14, and 612
- Language:
- English
- Description:
- Hypoxia has been identified as an important stimulus for gene expression during embryogenesis and in various pathological situations. Its influence under physiological conditions, however, has only been studied occasionally. We therefore investigated the effect of intermittent high altitude hypoxia on the mRNA expression of different cytokines and protooncogenes, but also of other genes described to be regulated by hypoxia, in the left ventricle (LV), the right ventricle (RV), atria and the lung of adult rats after simulation of hypoxia in a barochamber (5000 m, 4 hours to 10 days). Heme oxygenase-1 as well as transforming growth factor-β1 showed an increased expression in all regions of the heart and the lung at different periods of hypoxia. For lactate dehydrogenase-A, we found a significant up-regulation in the RV and the lung, for lactate dehydrogenase-B up-regulation in the RV, but down-regulation in the LV and the atria. Vascular endothelial growth factor was up-regulated in the RV, the LV and the lung, but down-regulated in the atria. Its receptor Flk-1 mRNA was significantly increased in the atria and RV only. Expression of c-fos was found in the LV and RV only after 4 hours of hypoxia. The level of c-jun was significantly increased in the LV but decreased in the atria. Our data clearly demonstrate that intermittent hypoxia is a modulator of gene expression under physiological conditions. It differently regulates the expression of distinct genes not only in individual organs but even within one organ, i.e. in the heart., E. Deindl, F. Kolář, E. Neubauer, S Vogel, W. Schaper, B. Ošťádal., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5500. Effect of iron, zinc and manganese shortage-induced change on photosynthetic pigments, some osmoregulators and chlorophyll fluorescence parameters in lettuce
- Creator:
- Roosta, H. R., Estaji, A., and Niknam, F.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- železo, zinek, mangan, iron, zinc, manganese, mikronutrienty, locika setá, kvantový výtěžek, fotosyntetické pigmenty, chlorophyll fluorescence transients, mikronutrients, Lactuca sativa, quantum yield, photosynthetic pigments, 2, and 581
- Language:
- Multiple languages
- Description:
- Although the beneficial role of Fe, Zn, and Mn on many physiological and biochemical processes is well established, effects of each of these elements on chlorophyll (Chl) a fluorescence and photosynthetic pigment contents is not well studied. The objective of this study was to evaluate effects of Fe, Zn, and Mn deficiency in two lettuce cultivars. The parameters investigated could serve also as physiological and biochemical markers in order to identify stress-tolerant cultivars. Our results indicated that microelement shortage significantly decreased contents of photosynthetic pigments in both lettuce cultivars. Chl a fluorescence parameters including maximal quantum yield of PSII photochemistry and performance index decreased under micronutrient deficiency, while relative variable fluorescence at J-step and minimal fluorescence yield of the dark-adapted state increased under such conditions in both cultivars. Micronutrient deficiency also reduced all parameters of quantum yield and specific energy fluxes excluding quantum yield of energy dissipation, quantum yield of reduction of end electron acceptors at the PSI, and total performance index for the photochemical activity. Osmoregulators, such as proline, soluble sugar, and total phenols were enhanced in plants grown under micronutrient deficiency. Fe, Zn, and Mn deficiency led to a lesser production of dry mass. The Fe deficiency was more destructive than that of Zn and Mn on the efficiency of PSII in both lettuce cultivars. Our results suggest that the leaf lettuce, which showed a higher efficiency of PSII, electron transport, quantum yield, specific energy fluxes, and osmoregulators under micronutrient deficiency, was more tolerant to stress conditions than crisphead lettuce., H. R. Roosta, A. Estaji, F. Niknam., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public