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102. Expression of serotonin receptors in mouse oocytes and preimplantation embryos

Creator:
Veselá, J., Rehák, P., Mihalik, J., Soňa Czikková, Pokorný, J., and Juraj Koppel
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Subject:
Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, expression, oocyte, preimplantation, serotonin, sumatriptan, 14, and 612
Language:
English
Description:
Serotonin receptors have been found in several reproductive organs as well as in the central nervous system. Serotonin-binding sites have been demonstrated in duck ovarian follicles and the testis, hamster ovaries, human granulosa cells and mouse placenta. Local production of serotonin by the rat ovary, oviduct, uterus and testis has also been reported. We analyzed the expression of three types of serotonin receptors: 5-HT1B, 5-HT2C and 5-HT1D by reverse transcription-polymerase chain reaction in mouse unfertilized oocytes and preimplantation embryos from zygotes to the blastocyst stage in vivo. Transcripts for 5-HT1B and 5-HT2C serotonin receptors were detected neither in unfertilized oocytes nor at any stages of in vivo developing preimplantation embryos. Serotonin 5-HT1D receptor mRNA was present in unfertilized oocytes, zygotes, 2-cell embryos, compacted morulae and in vivo produced expanded blatocysts. The expression of the mRNA 5-HT1D serotonin receptor was also detected in blastocysts cultured in vitro. When added to the culture medium, specific serotonin 5-HT1D agonist sumatriptan (1 μM) significantly inhibited the development of mouse embryos cultured in vitro. Demonstration of the expression of 5-HT1D serotonin receptor in mouse oocytes and preimplantation embryos supports the idea of a functional serotonin (5-HT1D) receptor in early mammalian development., J. Veselá, P. Rehák, J. Mihalik, S. Czikková, J. Pokorný, J. Koppel., and Obsahuje bibliografii
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http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

103. Familial dysbetalipoproteinemia in three patients with apoE 2*(Arg136→Cys) gene variant

Creator:
Michal Vrablík, Aleš Hořínek, Richard Češka, Tomáš Štulc, and Tomáš Kvasnička
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Subject:
Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, apolipoprotein E, rare variants, familial dysbetalipoproteinemia, 14, and 612
Language:
English
Description:
Apolipoprotein E (apoE) is a polymorphic protein which occurs in three common isoforms and more than 25 rare variants. Some of the rare apoE variants have been implicated in a dominant mode of inheritance of familial dysbetalipoproteinemia (FD). We have identified three unrelated apoE 2*(Arg136®Cys) carriers with FD. This finding supports the notion that although apoE 2*(Arg136®Cys) mutation is perhaps not sufficient to cause FD itself, the presence of other genetic and/or environmental factors can lead to the phenotypic expression of the disease in the carriers., M. Vrablík, A. Hořínek, R. Češka, T. Štulc, T. Kvasnička., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

104. Frequency-domain lifetime fluorometry of double-labeled creatine kinase

Creator:
Gregor, M., Martin Kubala, Evžen Amler, and Jiří Mejsnar
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Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, creatine kinase molecule, conformational change, FRET, frequency-domain lifetime fluorometry, 14, and 612
Language:
English
Description:
Myofibril-bound creatine kinase EC 2.7.3.2 (CK), a key enzyme of muscle energy metabolism, has been selected for studies of conformational changes that underlie the cellular control of enzyme activity. For fluorescence spectroscopy measurements, the CK molecule was double-labeled with IAF (5-iodoacetamidofluorescein) and ErITC (erythrosin 5'-isothiocyanate). Measurement of fluorescence resonance energy transfer (FRET) from fluorescein to erythrosin was used to obtain information about the donor-acceptor pair distance. Frequency-domain lifetime measurements evaluate the donor-acceptor distance in the native CK molecule as 7.8 nm. The Förster radius equals 5.3 nm with the resolution range from 0.2 to 1.0 nm. Erythrosin-fluorescein labeling (EFL) was tested for artificial conformational changes of the CK molecule with high-salt concentration treatment. The transition distance, defined by His-97 and Cys-283 and derived from a 3D model equals 0.766 nm for the open (inactive) form and 0.277 nm for the closed (reactive) form of the CK molecule. In this way, the resolution range of the used spectroscopy method is significant, concerning the difference of 0.489 nm. Nevertheless, the CK enzyme activity, assessed by the hexokinase-coupled assay, was diminished down to 1 % of the activity of the native enzyme. EFL is suitable for description of conformational behavior implied from the regulation of creatine kinase. However, the observed inhibition restricts EFL to studies of conformational changes during natural catalytic activity., M. Gregor, M. Kubala, E. Amler, J. Mejsnar., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

105. Fusion and fission in the visual pathways

Creator:
Kaposvári, P., Bognár, A., Csibri, P., Utassy, G., and Sáry, Gy.
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Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, audio-visual integration, double flash, fusion, illusion, 14, and 612
Language:
English
Description:
Inconsistent information from different modalities can be delusive for perception. This phenomenon can be observed with simultaneously presented inconsistent numbers of brief flashes and short tones. The conflict of bimodal information is reflected in double flash or fission, and flash fusion illusions, respectively. The temporal resolution of the vision system plays a fundamental role in the development of these illusions. As the parallel, dorsal and ventral pathways have different temporal resolution we presume that these pathways play different roles in the illusions. We used pathway-optimized stimuli to induce the illusions on separately driven visual streams. Our results show that both pathways support the double flash illusion, while the presence of the fusion illusion depends on the activated pathway. The dorsal pathway, which has better temporal resolution, does not support fusion, while the ventral pathway which has worse temporal resolution shows fusion strongly., P. Kaposvári, A. Bognár, P. Csibri, G. Utassy, Gy. Sáry., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

106. Gender differences in electrophysiological characteristics of idiopathic ventricular tachycardia originating from right ventricular outflow tract

Creator:
Yang, S.-G., Mikuláš Mlček, and Otomar Kittnar
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Fyziologie člověka a srovnávací fyziologie, gender, fyziologie, physiology, gender difference, electrophysiological characteristics, idiopathic ventricular, 14, and 612
Language:
English
Description:
It has become increasingly apparent in recent years that there are important differences of many cardiovascular disorders including ventricular tachycardias in men and women. Nevertheless, so far just few studies have addressed possible gender differences in electrophysiological characteristics of idiopathic ventricular tachycardia from right ventricular outflow tract (RVOT-VT), other than epidemiological ones. This study explored possible gender differences in electrophysiological characteristics and catheter ablation outcome in RVOT-VT patients. Ninety-three patients (mean age 38.7±15.5 years, 30 males) with idiopathic RVOT-VT were enrolled and analyzed in our study. Male patients had longer QRS width (99.9±19.4 ms vs. 88.4±20.7 ms, p=0.02). Female patients had lower right ventricular mean voltage (3.0±0.7 mV vs. 3.7±0.9 mV, p=0.03), and more low voltage zone over the right ventricular outflow tract free wall (27.0 % vs. 6.7 %, p=0.02). Eighty-one patients passed catheter ablation (23 males). The acute success rate, repeated catheter ablation rate and VT recurrence rate were similar in both genders. The present study provides evidence of the gender differences in electrophysiological findings in patients with idiopathic RVOT-VT. Studies on gender-specific differences in arrhythmia could lead to a better understanding of its mechanism(s) and provide valuable information for the development of optimal treatment strategies., S.-G. Yang, M. Mlček, O. Kittnar., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

107. Glutathione S-transferase does not play a role in multidrug resistance of L1210/VCR cell line

Creator:
Viera Boháčová, Kvačkajová, J., Miroslav Barančík, Drobná, Z., and Albert Breier
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Subject:
Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, P-glycoprotein, multidrug resistance, L1210 leukemic cell lines, cytostatic drugs, 14, and 612
Language:
English
Description:
Multidrug resistance of cancer cells is often accompanied by the (over)expression of integral plasma membrane P-glycoprotein, an ATP-dependent transport pump for diverse unrelated compounds. The glutathione detoxification system represents another mechanism that may be involved in multidrug resistance. In the multidrug-resistant L1210/VCR cell line obtained by long-term adaptation of parental L1210 cells to vincristine, an increased expression of P-glycoprotein has previously been established. In this paper, we investigated if the glutathione detoxification system is also involved in the multidrug resistance of these cells. L1210/VCR cells with resistance induced by adaptation to vincristine were also found to be cross-resistant to vinblastine, actinomycin D, mitomycin C, doxorubicin and cyclophosphamide. The resistance of the above cells to vincristine and doxorubicin was accompanied by a depression of drug accumulation (which has not yet been established for other drug). L1210/VCR cells are able to survive better than sensitive cells under conditions when glutathione was depleted by L-buthionine sulfoximine. Nevertheless, L-buthionine sulfoximine did not influence the resistance of L1210/VCR cells to vincristine. Moreover, the presence of sublethal concentrations of cytostatics neither changed the IC50 value of resistant cells to L-buthionine sulfoximine nor the cytoplasmic activity of glutathione S-transferase, the crucial enzyme of glutathione detoxification system. All the above findings indicate that the glutathione detoxification system is not involved in the mechanisms that ensure the multidrug resistance phenotype of L1210/VCR cells., V. Boháčová, J. Kvačkajová, M. Barančík, Z. Drobná, A. Breier., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

108. Gossypol inhibits follicle-stimulating hormone- and epidermal growth factor-stimulated expansion of oocyte-cumulus complexes from porcine preovulatory follicles

Creator:
Jaroslav Kolena, Vršanská, S., Eva Nagyová, and Marta Ježová
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Subject:
Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, gossypol, cumulus expansion, progesterone secretion, epidermal growth factor receptors, 14, and 612
Language:
English
Description:
The role of gossypol in the cumulus expansion of oocyte-cumulus complexes (OCC) isolated from large antral porcine follicles was investigated. Marked suppression of cumulus expansion stimulated with follicle-stimulating hormone (FSH) and epidermal growth factor (EGF) was observed in the presence of different concentrations of gossypol. Comparable inhibitory effects were obtained in the presence of NO donor, S-nitroso-N-acetylpenicillamine or sodium nitroprusside, suggesting that the inhibitory effect of gossypol may be mediated via NO generation. The inhibitory effect of gossypol on cumulus expansion of OCC was accompanied by inhibition of progesterone secretion of OCC and the decrease of [125I]EGF binding to granulosa cells., J. Kolena, S. Vršanská, E. Nagyová, M. Ježová., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

109. Granulocyte colony-stimulating factor and drugs elevating extracellular adenosine act additively to enhance the hemopoietic spleen colony formation in irradiated mice

Creator:
Michal Hofer, Milan Pospíšil, Jaromíra Netíková, Vladimír Znojil, and Jiří Vácha
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Subject:
Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, hemopietic stem cells, granulocyte colony-stimulating factor, dipyridamole, adenosine monophosphate, 14, and 612
Language:
English
Description:
The effects of combined administration of two drugs elevating extracellular adenosine, namely dipyridamole (DP) and adenosine monophosphate (AMP), and granulocyte colony-stimulating factor (G-CSF) on hemopoietic stem cells in vivo were investigated. The experiments were performed on mice using the endogenous spleen colony formation in gamma-irradiated animals as an endpoint. The results have shown that DP and AMP act additively with G-CSF to enhance spleen colony formation and thus the erythroid repopulation of the spleen. These findings indicate that the signaling pathways of G-CSF and drugs elevating extracellular adenosine can interact at the level of primitive hemopoietic stem cells. The enhancement of hemopoiesis-stimulating effects of G-CSF by DP and AMP, which are low-priced and clinically available drugs, could improve the cost-effectiveness of the therapy with G-CSF., M. Hofer, M. Pospíšil, J. Netíková, V. Znojil, J. Vácha., and Obsahuje bibliografii
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http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

110. Heat treatment inhibits skeletal muscle atrophy of glucocorticoid-induced myopathy in rats

Creator:
Morimoto, Y., Kondo, Y., Kataoka, H., Honda, Y., Kozu, R., Sakamoto, J., Nakano, J., Origuchi, T., Yoshimura, T., and Okita, M.
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Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, GC-induced myopathy, heat treatment, muscle fiber, Hsp72, capillary, 14, and 612
Language:
English
Description:
The purpose of this study was to investigate the influence of heat treatment on glucocorticoid (GC) -induced myopathy. Eight -week - old Wistar rats were randomly assigned to the control, Dex, and Dex + Heat groups. Dexamethasone (2 mg/kg) was injected subcutaneously 6 days per week for 2 weeks in the Dex and Dex + Heat group. In the Dex + Heat group, heat treatment was performed by immersing hindlimbs in water at 42 °C for 60 min, once every 3 days for 2 weeks. The extensor digitorum longus muscle was extracted following 2 weeks of experimentation. In the Dex + Heat group, muscle fiber diameter, capillary/muscle fiber ratio, and level of heat shock protein 72 were significantly higher and atrogene expression levels were significantly lower than in the D ex group. Our results suggest that heat treatment inhibits the development of GC -induced myopathy by decreas ing atrogene expression and increasing angiogenesis., Y. Morimoto, Y. Kondo, H. Kataoka, Y. Honda, R. Kozu, J. Sakamoto, J. Nakano, T. Origuchi, T. Yoshimura, M. Okita., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public