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5502. Effect of leptin and insulin on chick embryonic muscle cells and hepatocytes
- Creator:
- Dalma Lamošová and Zeman, M.
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, inzulin, leptin, svalové buňky, insulin, muscle cells, chick embryo, hepatocytes, 14, and 612
- Language:
- English
- Description:
- In the present study we used the primary cultures of chick embryonic muscle and liver cells as a model for potential mutual combination effects of leptin and insulin, respectively. The influence of both hormones on the proliferation and protein synthesis was dose-dependent and related to the age of embryos from which the cells were isolated. Leptin (10 and 100 ng/well) increased the proliferation (estimated by DNA content and incorporation of labeled thymidine into DNA) and protein synthesis (determined by incorporation of labeled leucine into proteins) of muscle cells. The effect of leptin and insulin in muscle cells was similar. In younger embryo (11-day-old) the lower dose of leptin was more effective than the higher one compared to the insulin effect. Mutual effects of leptin and insulin were neither additive nor synergistic and were equivalent to the effects of individual hormones. In hepatocytes the influence of leptin was dependent on the age at which the cells were isolated (11- and 19-day-old embryos). The presence of insulin neither potentiated nor inhibited the effect of leptin., D. Lamošová, M. Zeman., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5503. Effect of light intensity on the age dependence of nonphotochemical fluorescence quenching in wheat leaf
- Creator:
- Nesterenko, T. V., Shikhov, V. N., and Tikhomirov, A. A.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, chlorophyll fluorescence induction, leaf age, photosystem II, 2, and 581
- Language:
- Multiple languages
- Description:
- The effects of actinic light (AL) intensity on the age dependence of nonphotochemical fluorescence quenching (qN) and effective quantum yield in PSII (ΦPSII) were studied in continuously illuminated wheat leaves of the upper tier. Regular changes were revealed in both age dependence of qN at elevated AL intensities and light curves of qN. These changes are related to alterations in strategies of redistribution and use of absorbed light energy by the photosynthetic apparatus at different stages of wheat leaf development. Unlike ΦPSII, qN as a parameter was more sensitive to the differences in the leaf age at a certain range of light intensities. At the same time, the stability of qN at moderate light intensities may serve as an indication of leaf maturity., T. V. Nesterenko, V. N. Shikhov, A. A. Tikhomirov., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5504. Effect of light quality on leaf photosynthetic characteristics and fruit quality of peach (Prunus persica L. Batch)
- Creator:
- Zhang, B.-B., Xu, J.-L., Zhou, M., Yan, D.-H., and Ma, R.-J.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, appearance, internal quality, irradiance spectrum, 2, and 581
- Language:
- Multiple languages
- Description:
- Different light filters affect leaf photosynthetic features and fruit quality. Consequently, selecting the appropriate covering filter for rain-shelter cultivation of peaches is a key part of successful production. We used a late-maturing peach variety ‘Xiahui 8’ to study differences in leaf photosynthetic features, chlorophyll fluorescence characteristics, and fruit quality under neutral, red, yellow, green, and blue filter, with natural light as control. The results showed that the leaf photosynthetic ability and internal quality under the neutral filter treatment were elevated compared with the control, and the appearance color was the same as the control. Leaves under neutral filter could maintain higher photosynthetic ability than other filter treatments. In addition, the fruits could also keep higher quality when treated with neutral filter. Therefore, the application of neutral filter in rain-shelter cultivation of ‘Xinhui 8’ peaches is recommended for maintaining high photosynthetic capacity and for improving fruit quality., B.-B. Zhang, J.-L. Xu, M. Zhou, D.-H. Yan, R.-J. Ma., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5505. Effect of Liposomal Muramyl Tripeptide Phosphatidyl-ethanolamine and Indomethacin on Hematopoietic Recovery in Irradiated Mice
- Creator:
- Naděžda O. Macková and Peter Fedoročko
- Format:
- print, bez média, and svazek
- Type:
- article, studie, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie člověka, human physiology, Radioprotection, Hematopoiesis, Muramyl peptide, Indomethacin, 14, and 612
- Language:
- English
- Description:
- The effects of liposomal muramyl tripeptide phosphatidylethanolamine (MTP-PE/MLV, radioprotective immunomodulator; 10 mg/kg) and indomethacin (INDO, inhibitor of prostaglandin production; 2 mg/kg) on post-irradiation recovery of hematopoietic functions in mice were investigated. Two agents with distinct radioprotective mechanisms were administered alone or in combination 24 h and 3 h before exposure to 7 Gy 60Co radiation. In the post-irradiation period (3-14 days) combined pre-treatment of mice accelerated recovery of bone marrow cellularity, weight of spleen and myelopoietic and erythropoietic activity in both hematopoietic organs, compared to treatment with MTP-PE/MLV or indomethacin alone. In the peripheral blood, improved radioprotective effects of combined drug administration were found in the recovery of reticulocytes and platelet count. No further significant differences in the recovery of leukocyte count were observed in the examined groups until post-irradiation day 14. Within the first 3-6 post-irradiation days, the bone marrow and peripheral blood smears of mice pre-treated with indomethacin alone or its combination with MTP-PE/MLV more frequently featured blast cells and large cells with abundant cytoplasm which could be considered the hematopoietic stem cells., N. O. Macková, P. Fedoročko., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5506. Effect of lithium on smooth muscle contraction and phosphorylation of myosin light chain by MLCK
- Creator:
- Tang, Z. Y., Liu, Z. N., Chen, D. P., Fu, L., Ai, Q. D., and Lin, Y.
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, lithium, svaly, muscles, Phosphorylation of myosin light chain (MLC 20), Myosin Mg2+-ATPase, 14, and 612
- Language:
- English
- Description:
- The aims of our study were to investigate into the effect of lithium on smooth muscle contraction and phosphorylation of myosin light chain (MLC20) by MLCK and to find out the clue of its mechanism. Isolated rabbit duodenum smooth muscle strips were used to study the effects of lithium on their contractile activity under the condition of Krebs’ solution by means of HW-400S constant temperature smooth muscle trough. Myosin and MLCK were purified from the chicken gizzard smooth muscle. Myosin phosphorylation was determined by Glycerol-PAGE, myosin Mg2+-ATPase activity was measured by Pi liberation method. Lithium (10-40 mM) inhibited the contraction in duodenum in a dose-related and time-dependent manner. Lithium could also inhibit the extent of myosin phosphorylation in a dose-related and time-dependent manner, whereas it inhibited Mg2+-ATPase activity in a dose-rel ated manner. Lithium inhibited smooth muscle contraction by inhibition of myosin phosphorylation and Mg2+-ATPase activity., Z. Y. Tang, Z. N. Liu, L. Fu, D. P. Chen, Q. D. Ai, Y. Lin., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5507. Effect of low and high temperatures on infectivity of Encephalitozoon cuniculi spores suspended in water
- Creator:
- Koudela, Břetislav, Kučerová, Štěpánka, and Hudcovic, Tomáš
- Format:
- Type:
- model:internalpart and TEXT
- Subject:
- microsporidia, temperature, infectivity, and SCID mice
- Language:
- English
- Description:
- The survival of Encephalitozoon cuniculi Lcvaditi, Nicolau et Schoen, 1923 spores suspended in distilled water and exposed at defined temperatures was investigated. Infectivity of E. cuniculi spores was tested by inoculation of SCID mice. There was no marked loss of infectivity of spores stored at 4°C for two years or frozen at -12°C and -24°C for 1, 8, and 24 h. Although there was a remarkable loss of infectivity, spores remained infective after freezing at -70°C for 1 and 8 h. Heating at 60°C and 70°C for 5 min and 1 min, respectively, rendered the microsporidia non-infective. These findings demonstrate that E. cuniculi spores suspended in water can survive freezing temperatures but lost infectivity in water that reached a temperature of 60°C at 5 min.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5508. Effect of low irradiance on the photosynthetic performance and spiking of Phalaenopsis
- Creator:
- Liu, Y.-C., Liu, C.-H., Lin, Y.-C., Lu, C.-H., Chen, W.-H., and Wang, H.-L.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, CAM, carbohydrate, chlorophyll fluorescence, flower stalk, gas exchange, oxygen evolution, 2, and 581
- Language:
- Multiple languages
- Description:
- Lowering irradiance can delay the flower stalk, i.e., spike development, in order to schedule flowering time of Phalaenopsis; however, the effect on photosynthetic performance and spiking inhibition remains poorly understood. We compared light and shade treatments of Phalaenopsis aphrodite subsp. formosana in order to determine how limiting light affects day-night changes in the photosynthetic capacity of leaves and the carbon pool of leaves and stems resulting in delayed spiking. The low irradiance treatment [20 μmol(photon) m-2 s-1] for six weeks did not affect potential functions of photosynthetic apparatus estimated by chlorophyll a fluorescence analysis, but it significantly reduced the net CO2 uptake and O2 evolution rates, carbohydrate and organic acid concentrations, and amplitudes of CAM activity in new and fully expanded leaves of Phalaenopsis and delayed the spiking compared with the control kept at 150 μmol(photon) m-2 s-1. The shortened stem contained a remarkably high sucrose concentration, accounting for more than 80% of total soluble sugars for both treatments throughout the day. Moreover, the sucrose concentration was unaffected by the lowering of irradiance. The relationship between the sucrose content and spiking seemed to be loose; the major factor(s) for spiking in Phalaenopsis remained to be ascertained as the flower stalk bud is attached to the shortened stem., Y.-C. Liu, C.-H. Liu, Y.-C. Lin, C.-H. Lu, W.-H. Chen, H.-L. Wang., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5509. Effect of maturation on the resistance of rat hearts against ischemia. Study of potential molecular mechanisms
- Creator:
- Grecsová, L., Farkašová, V., Gáblovský, I., Khandelwal, V. K. M., Iveta Bernátová, Tatarková, Z., Peter Kaplán, and Ravingerová, T.
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, stárnutí, aging, myocardial ischemia, preconditioning, survival cascades, 14, and 612
- Language:
- English
- Description:
- a1_Reduced tolerance to ischemia/reperfusion (IR) injury has been shown in elder human and animal hearts, however, the onset of this unfavorable phenotype and cellular mechanisms behind remain unknown. Moreover, aging may interfere with the mechanisms of innate cardioprotection (preconditioning, PC) and cause defects in protective cell signaling. We studied the changes in myocardial function and response to ischemia, as well as selected proteins involved in “pro-survival” pathways in the hearts from juvenile (1.5 months), younger adult (3 months) and mature adult (6 months) male Wistar rats. In Langendorffperfused hearts exposed to 30-min ischemia/2-h reperfusion with or without prior PC (one cycle of 5-min ischemia/5-min reperfusion), we measured occurrence of reperfusion-induced arrhythmias, recovery of contractile function (left ventricular developed pressure, LVDP, in % of pre-ischemic values), and size of infarction (IS, in % of area at risk size, TTC staining and computerized planimetry). In parallel groups, LV tissue was sampled for the detection of protein levels (WB) of Akt kinase (an effector of PI3-kinase), phosphorylated (activated) Akt (p-Akt), its target endothelial NO synthase (eNOS) and protein kinase Cε (PKCε) as components of “pro-survival” cascades. Maturation did not affect heart function, however, it impaired cardiac response to lethal IR injury (increased IS) and promoted arrhythmogenesis. PC reduced the occurrence of malignant arrhythmias, IS and improved LVDP recovery in the younger animals, while its efficacy was attenuated in the mature adults. Loss of PC protection was associated with age-dependent reduced Akt phosphorylation and levels of eNOS and PKCε in the hearts of mature animals compared with the younger ones, as well as with a failure of PC to upregulate these proteins., a2_Agingrelated alterations in myocardial response to ischemia may be caused by dysfunction of proteins involved in protective cell signaling that may occur already during the process of maturation., L. Griecsová, V. Farkašová, I. Gáblovský, V. K. M. Khandelwal, I. Bernátová, Z. Tatarková, P. Kaplan, T. Ravingerová., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
5510. Effect of melatonin on the release of prothoracicotropic hormone from the brain of Periplaneta americana (Blattodea: Blattidae)
- Creator:
- Richter, Klaus, Peschke, Elmar, and Peschke, Dorothee
- Format:
- print, text, and regular print
- Type:
- article, bibliography, model:article, and TEXT
- Subject:
- zoologie, entomologie, hmyz, Blattodea, Periplaneta americana, mozek, hormony, prothoracikotropní hormon, uvolňování hormonu, melatonin, účinky, and 595.2/.7
- Language:
- English
- Description:
- The occurrence of melatonin is known in nearly all organisms, but nothing is known exactly about its function outside of vertebrates. Long-term perifusions as well as short-term batch incubations of brains and moulting glands of the cockroach Periplaneta americana were used to identify the effect of melatonin on the release of prothoracicotropic hormone, a glandotropic neuropeptide in the brain, which stimulates the production of the moulting hormone ecdysone in the moulting gland. This is the first experimental evidence of a neurohormonal releasing effect of melatonin in the insect nervous system., Klaus Richter, Elmar Peschke, Dorothee Peschke, and Lit
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public