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302. Silymarin component 2,3-dehydrosilybin attenuates cardiomyocyte damage following hypoxia/reoxygenation by limiting oxidative stress

Creator:
Gabrielová, E., Vladimír Křen, Martin Jabůrek, and Martin Modrianský
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Subject:
Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, silymarin, dehydrosilybin, neonatal rat cardiomyocytes, postconditioning, reactive oxygen species, 14, and 612
Language:
English
Description:
Ischemic postconditioning and remote conditioning are potentially useful tools for protecting ischemic myocardium. This study tested the hypothesis that 2,3-dehydrosilybin (DHS), a flavonolignan component of Silybum marianum , could attenuate cardiomyocyte damage following hypoxia/ reoxygenation by decreasing the generation of reactive oxygen species (ROS). After 5-6 days of cell culture in normoxic conditions the rat neonatal cardiomyocytes were divided into four groups. Control group (9 h at normoxic conditions), hypoxia/ reoxygenation group (3 h at 1 % O2 , 94 % N2 and 5 % CO2 followed by 10 min of 10 μmol·l -1 DHS and 6 h of reoxygenation in normoxia) and postconditioning group (3 h of hypoxia, three cycles of 5 min reoxygenation and 5 min hypoxia followed by 6 h of normoxia). Cell viability assess ed by propidium iodide staining was decreased after DHS treatment consistent with increased levels of lactatedehydrogenase (LDH) after reoxygenation. LDH leakage was significantly reduced when cardiomyocytes in the H/Re group were exposed to DHS. DHS treatment reduced H2O2 production and also decreased the generation of ROS in the H/Re group as evidenced by a fluorescence indicator. DHS treatment reduces reoxygenation-induced injury in cardiomyocytes by attenuation of ROS generation, H2O2 and protein carbonyls levels. In addition, we found that both the postconditioning protocol and the DHS treatment are associated with restored ratio of phosphorylated/total protein kinase C epsilon, relative to the H/Re group. In conclusion, our data support the protective role of DH S in hypoxia/reperfusion injury and indicate that DHS may act as a postconditioning mimic., E. Gabrielová, V. Křen, M. Jabůrek, M. Modrianský., and Obsahuje bibliografii
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http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

303. Similar enhancement of BKCa channel function despite different aerobic exercise frequency in aging cerebrovascular myocytes

Creator:
Li, Na, Liu, Bailin, Xiang, Sharon, and Shi, Lijun
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Subject:
Fyziologie člověka a srovnávací fyziologie, stárnutí, fyziologie, aging, physiology, BKCa channel, aerobic exercise training, celebral artery, biophysical properties, 14, and 612
Language:
English
Description:
Aerobic exercise showed beneficial influence on cardiovascular systems in aging, and mechanisms underlying vascular adaption remain unclear. Large-conductance Ca2+ -activated K+(BKCa) channels play critical role s in regulating cellular excitability and vascular tone. This study determin ed the effects of aerobic exercise on aging -associated functional changes in BK Ca channels in cerebrovascular myocytes, Male Wistar rats aged 20- 22 mo nths were randomly assigned to sedentary (O -SED), low training frequency (O-EXL), and high training frequency group (O -EXH). Young rats were used as control. Compared to young rats, w hole -cell BK Ca current was decreased, and amplitude of spontaneous transient outward currents were reduced. The open probability and Ca2+/voltage sensitivity of single BK Ca channel were declined in O -SED, accompanied with a reduction of tamoxifen-induced BK Ca activation; the mean open time of BK Ca channels was shortened whereas close time was prolonged. Aerobic exercise training markedly alleviated the aging-associated decline independent of training frequency. Exercise three times rather than five times weekly may be a time and cost-saving training volume required to offer bene ficial effects to offset the functional declines of BK Ca during aging., Na Li, Bailin Liu, Sharon Xiang, Lijun Shi., and Obsahuje bibliografii
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304. Sirtuin 1 modulation in rat model of acetaminophen-induced hepatotoxicity

Creator:
Wojnarová, L., Nikolína Kutinová-Canová, Hassan Farghali, and Tomáš Kučera
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Fyziologie člověka a srovnávací fyziologie, fyziologie, játra, physiology, liver, SIRT1, resveratrol, acetaminophen, CAY10591, 14, and 612
Language:
English
Description:
Sirtuin 1 (SIRT1) is involved in important biological processes such as energy metabolism and regulatory functions of the cell cycle, apoptosis, and inflammation. Our previous studies have shown hepatoprotective effect of polyphenolic compound resveratrol, which is also an activator of SIRT1. Therefore, the aim of our present study was to clarify the role of SIRT1 in process of hepatoprotection in animal model of drug-induced liver damage. Male Wistar rats were used for both in vivo and in vitro studies. Hepatotoxicity was induced by single dose of acetaminophen (APAP). Some rats and hepatocytes were treated by resveratrol or synthetic selective activator of sirtuin 1 (CAY10591). The degree of hepatotoxicity, the activity and expression of the SIRT1 were determined by biochemical, histological and molecular-biological assessments of gained samples (plasma, liver tissue, culture media and hepatocytes). Resveratrol and CAY attenuated APAP-induced hepatotoxicity in vivo and in vitro. Moreover, both drugs enhanced APAPreduced SIRT1 activity. Our results show that modulation of the SIRT1 activity plays a role in hepatoprotection. Synthetic activators of SIRT1 would help in understanding the role of SIRT1 and are therefore a major boost towards the search for specific treatment of liver disease., L. Wojnarová, N. Kutinová Canová, H. Farghali, T. Kučera., and Obsahuje bibliografii
Rights:
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305. Skin blood flowmotion and microvascular reactivity investigation in hypercholesterolemic patients with out clinically manifest arterial diseases

Creator:
Rossi, M., Carpi, A., Di Maria, C., Franzoni, F., Galetta, F., and Santoro, G.
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Subject:
Fyziologie člověka a srovnávací fyziologie, fyziologie, hypercholesterolémie, acetylcholin, Fourierova analýza, physiology, hypercholesterolemia, acetylcholine, Fourier analysis, endothelial function, laser Doppler flowmetry, flowmotion, sodium nitroprusside, 14, and 612
Language:
English
Description:
Fourier spectral analysis of fore arm skin laser Doppler flowmetry (LDF) signal was performed in fifteen hypercholesterolemic patients (HP), without clinically manifest arterial diseases, and in fifteen age-matched healthy control subjects (CS), in order to investigate skin blood flowmotion (SBF). The LDF frequency intervals studied were: 0.01-1.6 Hz total spectrum, as well as 0.01-0.02 Hz (endothelial), 0.02-0. 06 Hz (sympathetic), 0.06-0.2 Hz (myogenic), 0.2-0.6 Hz (respiratory) and 0.6-1.6 Hz (cardiac). Skin microvascular reactivity (MVR ) to acetylcholine (ACh) and to sodium nitroprusside (SNP) iontophoresis was also investigated. HP showed a lower post-ACh increase in power spectral density (PSD) of the 0.01-0.02 Hz SBF subinterval compared to CS (1.80±1.73 PU 2 /Hz vs 3.59±1.78 PU 2 /Hz, respectively; p<0.005), while they did not differ in MVR from CS. In eleven HP the 0.01-0.02 Hz SBF subinterval showed a higher post-ACh PSD increase near to the statistical significance after 10 weeks of rosuvastatin therapy (10 mg/day) compared to pretreatment test (3.04±2.95 PU 2 /Hz vs 1.91±1.94 PU 2 /Hz; p=0.07). The blunted post-ACh increase in PSD of the 0.01-0.02 Hz SBF subinterval in HP suggests a skin endothelial dysfunction in these patients. This SBF abnormality showed a tendency to improve after rosuvastatin therapy in eleven treated patients., M. Rossi ... [et al.]., and Obsahuje seznam literatury
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http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

306. Slowed inactivation at positive potentials in a rat axonal K+ channel is not due to preferential closed-state inactivation

Creator:
Babes, A., Lörinczi, E., Ristoiu, V., Flonta, M.-L., and Reid, G.
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Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, potassim channel, inactivation, axon, rat, 14, and 612
Language:
English
Description:
We have investigated slow inactivation in a rat axonal K+ channel, the I channel. Using voltage steps to potentials between -70 mV and +80 mV, from a holding potential of -100 mV, we observed a marked slowing of inactivation at positive potentials: the time constant was 4.5±0.4 s at -40 mV (mean ± S.E.M.), increasing to 14.7±2.0 s at +40 mV. Slowed inactivation at positive potentials is not consistent with published descriptions of C-type inactivation, but can be explained by models in which inactivation is preferentially from closed states (which have been developed for Kv2.1 and some Ca2+ channels). We tested two predictions of preferential closed-state models: inactivation should be more rapid during a train of brief pulses than during a long pulse to the same potential, and the cumulative inactivation measured with paired pulses should be greater than the inactivation at the same time during a continuous pulse. The I channel does not behave according to these predictions, indicating that preferential closed-state inactivation does not explain the slowing of inactivation we observe at positive potentials. Inactivation of the I channel therefore differs both from C-type inactivation, as presently understood, and from the inactivation of Kv2.1., A. Babes, E. Lörinczi, V. Ristoiu, M.L. Flonta, G. Reid., and Obsahuje bibliografii
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307. Spontaneous variability and reactive postural beat-to-beat changes of integral ECG body surface potential maps

Creator:
Eva Kellerová, Vavrinec Szathmáry, Kozmann, G., Katalin Haraszti, and Tarjányi, Z.
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Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, integral ECG body surface maps, beat-to-beat variability, respiratory and low frequency oscillations, postural effects, 14, and 612
Language:
English
Description:
There is virtually no information on spontaneous variability of ECG body surface potential maps (BSPMs) and on dynamics of their reactive changes in healthy subjects. This study evaluated quantitatively the depolarization (QRS) and repolarization (QRST) parameters derived from the respective integral BSPMs, constructed beat-to-beat, from continual body surface ECG records in 9 healthy men resting supine, during head-up tilting and sitting. Spontaneous variability of the BSPMs parameters, both at rest and during postural reactions, was characterized by significant respiratory and low frequency oscillations, more pronounced when related to repolarization. Head-up tilting and sitting-up evoked significant decrease in the QRST-BSPM amplitudes, widening of the angle α and reduction of nondipolarity indexes, compared to the respective supine values. All these changes were gradual, characterized by transition phenomena and prolonged after-effect s. Tilting back to horizontal restored the resting supine va lues. The postural effects on depolarization were individually more variable and in the average showed a minimal QRS-BSPM amplitude increase. Beat-to-beat analysis of a train of ECG BSPMs provided the first evidence of spontaneous, non-random, respiratory and low frequency oscillations of the ventricula r repolarization pattern, and the first insight into the dynamics of body posture associated changes in ventricular recovery., E. Kellerová, V. Szathmáry, G. Kozmann, K. Haraszti, Z. Tarjányi., and Obsahuje bibliografii
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308. Stem cells regenerative properties on new rat spinal fusion model

Creator:
Klíma, K., Vaněček, V., Aleš Kohout, Jiroušek, O., René Foltán, Vladimír Machoň, Gabriela Pavlíková, Pavla Jendelová, Eva Syková, and Jiří Šedý
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Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, animal model, rat, MSCs, bone graft substitute, spinal fusion, 14, and 612
Language:
English
Description:
Stem cells biology is one of the most frequent topic of physiological research of today. Spinal fusion represents common bone biology challenge. It is the indicator of osteoinduction and new bone formation on ectopic model. The purpose of this study was to establish a simple model of spinal fusion based on a rat model including verification of the possible use of titanium microplates with hydroxyapatite scaffold combined with human bone marrow-derived mesenchymal stem cells (MSCs). Spinous processes of two adjacent vertebrae were fixed in 15 Wistar rats. The space between bony vertebral arches and spinous processes was either filled with augmentation material only and covered with a resorbable collagen membrane (Group 1), or filled with augmentation material loaded with 5 × 10 6 MSCs and covered with a resorbable collagen membrane (Group 2). The rats were sacrificed 8 weeks after the surgery. Histology, histomorphometry and micro-CT were performed. The new model of interspinous fusion was safe, easy, inexpensive, with zero mortality. We did not detect any substantial pathological changes or tumor formation after graft implantation. We observed a nonsignificant effect on the formation of new bone tissue between Group 1 and Group 2. In the group with MSCs (Group 2) we described mino r inflamatory response which indicates the imunomodulational and antiinflamatory role of MSCs. In conclusion, this new model proved to be easy to use in small animals like rats., K. Klíma, V. Vaněček, A. Kohout, O. Jiroušek, R. Foltán, J. Štulík, V. Machoň, G. Pavlíková, P. Jendelová, E. Syková, J. Šedý., and Obsahuje bibliografii
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309. Subconvulsive dose of kainic acid transiently increases the locomotor activity of adult wistar rats

Creator:
Vladimír Riljak, Dana Marešová, Pokorný, J., and Kateřina Jandová
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Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, kainic acid, laboras, behavior, wistar rat, locomotor activity, 14, and 612
Language:
English
Description:
Kainic acid (KA) is a potent neurotoxic substance valuable in research of temporal lobe epilepsy. We tested how subconvulsive dose of KA influences spontaneous behavior of adult Wistar rats. Animals were treated with 5 mg/kg of KA and tested in Laboras open field test for one hour in order to evaluate various behavioral parameters. Week after the KA treatment animals were tested again in Laboras open field test. Finally, rat’s brains were sliced and stained with Fluoro-Jade B to detect possible neuronal degeneration. Treatment with KA increased the time spent by locomotion (p<0.01), exploratory rearing (p<0.05) and animals traveled longer distance (p<0.01). These parameters tended to increase thirty minutes after KA administration. Week after the treatment we did not found differences in any measured behavioral parameter. Histology in terms of Fluoro-Jade B staining did not reveal any obvious neuronal damage in hippocampus. These results demonstrate that subconvulsive KA dose changes the behavioral parameters only transiently. Clarification of timing of the KA induced changes may contribute to understand mutual relationship between non-convulsive seizures and behavioral/cognitive consequences., V. Riljak, D. Marešová, J. Pokorný, K. Jandová., and Obsahuje bibliografii
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http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

310. Surface changes in type II pneumocytes isolated from rats during the cultivation

Creator:
Zuzana Kováčiková, Tátrai, E., and Adamis, Z.
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Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, pneumocytes type II, lectin binding, alkaline phosphatase, rat, 14, and 612
Language:
English
Description:
Z. Kováčiková, E. Tátrai, Z. Adamis. and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public