Number of results to display per page
Search Results
1482. Structure, function, and pharmacology of NMDA receptor channels
- Creator:
- Vyklicky, V., Korinek, M., Smejkalova, T., Aleš Balík, Krausova, B., Kaniakova, M., Lichnerova, K., Cerny, J., Krusek, J., Ivan Dittert, Martin Horák, and Vyklicky, L.
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, iontové kanály, farmakologie, ion channels, pharmacology, glutamate receptor, NMDA receptor, channel blocker, synaptic transmission, 14, and 612
- Language:
- English
- Description:
- NMDA receptors have received much attention over the last few decades, due to their role in many types of neural plasticity on the one hand, and their involvement in excitotoxicity on the other hand. There is great interest in developing clinically relevant NMDA receptor antagonists that would block excitotoxic NMDA receptor activation, without interfering with NMDA receptor function needed for normal synaptic transmission and plasticity. This review summarizes current understanding of the structure of NMDA receptors and the mechanisms of NMDA receptor activation and modulation, with special attention given to data describing the properties of various types of NMDA receptor inhibition. Our recent analyses point to certain neurosteroids as NMDA receptor inhibitors with desirable properties. Specifically, these compounds show use-dependent but voltage-independent block, that is predicted to preferentially target excessive tonic NMDA receptor activation. Importantly, neurosteroids are also characterized by use-independent unblock, compatible with minimal disruption of normal synaptic transmission. Thus, neurosteroids are a promising class of NMDA receptor modulators that may lead to the development of neuroprotective drugs with optimal therapeutic profiles., V. Vyklicky ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1483. Study on effects of electrical stimulation on rabbit esophageal body motility in vivo
- Creator:
- Zhang, L, Wang, B, Jin, H, Zhao, W, and Zhao, C
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fyziologie člověka, human physiology, Electrical stimulation, Esophagus motility, High-resolution manometry, 14, and 612
- Language:
- English
- Description:
- Electric stimulation (ES) could induce contraction of intestinal smooth muscle. The aim of this study was to analyze the effects of ES on esophageal motility and the underlying mechanism in vivo. Twenty-eight rabbits were equipped with a pair of subserosa electrodes (connected to an electrical stimulator) in the lower segment of the esophagus. The ES signal consisted of bipolar rectangular pulse trains, lasting for 3 s, with different amplitudes (1 mA, 3 mA, 5 mA and 10 mA), and frequencies (10 Hz, 20 Hz and 50 Hz). The amplitude of the contraction was recognized by high-resolution manometry. The effect of ES was tested under anesthesia and following administration of atropine, phentolamine or L-NAME. ES induced esophageal contraction at the stimulated site. A statistically significant increase in esophageal pressure was observed when the stimulation amplitude was above 3 mA. The increase in esophageal pressure was associated with the amplitude of stimulus as well as the frequency. During stimulation, atropine, phentolamine and L-NAME had no effect on the increase of esophageal pressure induced by ES. These findings implied that ES induced esophageal contraction were not mediated via the NANC, adrenergic or cholinergic pathway. The amplitude of esophageal contraction was current and frequency dependent., L. Zhang, W. Zhao, C. Zhao, H. Jin, B. Wang, B. Wang., and Seznam literatury
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1484. Subacute exposure to alcohol in relation to bone microstructure of mice
- Creator:
- Sarocka, A, Kovacova, V, Omelka, R, Bauerova, M, Kapusta, E, Goc, Z, Formicki, G, and Martiniakova, M
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- kosti, myši, bones, mice, alcohol, microstructure, 14, and 612
- Language:
- English
- Description:
- Our study aimed to investigate subacute exposure to alcohol in relation to bone microstructure of mice. Animals from experimental (E) group drank a solution composed of 15 % ethanol and water for 14 days (one remodeling cycle), while those from control (C) group drank only water. In the compact bone of E group, decreased bone formation and increased porosity were observed which corresponds with lower levels of serum alkaline phosphatase and glutathione. Alcohol significantly increased sizes of primary osteon's vascular canals and decreased those of secondary osteons, Haversian canals. Relative bone volume, bone mineral density (BMD), relative bone volume without marrow cavity were also lower in E group. On the contrary, trabecular bone microstructure did not differ significantly between E and C groups. Liver function test showed higher levels of alanine aminotransferase, aspartate aminotransferase in alcohol-fed mice. Serum calcium, phosphate were significantly lower in E group. According to our study, only changes in compact bone microstructure of mice following one remodeling cycle were observed due to both direct and indirect effects of alcohol., A. Sarocka, V. Kovacova, R. Omelka, M. Bauerova, E. Kapusta, Z. Goc, G. Formicki, M. Martiniakova., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1485. Subcellular redistribution of trimeric G-proteins - potential mechanism of desensitization of hormone response: internalization, solubilization, down-regulation
- Creator:
- Drastichová, Z., Lenka Bouřová, Václav Lisý, Lucie Hejnová, Rudajev, V., Jiří Stöhr, Dana Durchánková, Ostašov, P., Jan Teisinger, Tomáš Soukup, Jiří Novotný, and Petr Svoboda
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, neurovědy, mozek, neurosciences, brain, subcellular fractionation, trimeric G-proteins, desensitization, Na, K-ATPase, 14, and 612
- Language:
- English
- Description:
- Agonist-induced subcellular redistribution of G-protein coupled receptors (GPCR) and of trimeric guanine-nucleotide binding regulatory proteins (G-proteins) represent mechanisms of desensitization of hormone response, which have been studied in our laboratory since 1989. This review brings a short summary of these results and also presents information about related literature data covering at least small part of research carried out in this area. We have also mentioned sodium plus potassium dependent adenosine triphosp hatase (Na, K-ATPase) and 3H-ouabain binding as useful reference standard of plasma membrane purity in the brain., Z. Drastichová, L. Bouřová, V. Lisý, L. Hejnová, V. Rudajev, J. Stöhr, D. Durchánková, P. Ostašov, J. Teisinger, T. Soukup, J. Novotný, P. Svoboda., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1486. Subconvulsive dose of kainic acid transiently increases the locomotor activity of adult wistar rats
- Creator:
- Vladimír Riljak, Dana Marešová, Pokorný, J., and Kateřina Jandová
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- 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
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1487. Substance MCS-18 isolated from helleborus purpurascens is a potent antagonist of the capsaicin receptor, TRPV1, in rat cultured sensory neurons
- Creator:
- Neacsu, C., Ciobanu, C., Barbu, I., Toader, O., Szegli, G., Kerek, F., and Babes, A.
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, bolest, rostlinné extrakty, pain, plant extracts, TRP channels, DRG, capsaicin, 14, and 612
- Language:
- English
- Description:
- Extracts of Helleborus roots were traditionally used in the Balkan area for their analgesic action. We report that the pure natural product MCS-18 isolated from this source is a potent, specific and reversible antagonist of the capsaicin receptor, TRPV1, expressed in rat dorsal root ganglion (DRG) neurons. TRPV1 is a nonselective cation channel expressed in a subset of cutaneous and visceral sensory nerve endings and activated by noxious heat, acidity and fatty acid metabolites of arachidonic acid, with a decisive role in inflammatory heat hyperalgesia. MCS-18 inhibited the increase in intracellular calcium concentration evoked in DRG neurons by capsaicin (300 nM) and low pH (5.5) but not by heat (43 ºC). The substance had no effect on the responses mediated by acid-sensing ion channels (ASICs) or the irritant receptor TRPA1. Whole-cell patch-clamp was used to confirm the inhibition of capsaicin-induced currents by MCS-18 which was dose-dependent. The mechanism of inhibition does not require an intact cell, as capsaicin-induced currents were also inhibited in the excised outside-out configuration. The antagonism of the capsaicin and proton action on native TRPV1 by MCS-18 may be of interest for pain therapy., C. Neacsu ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1488. Success and failure of cardiovascular disease prevention in Czech Republic over the past 30 years. Czech part of the EUROASPIRE I-IV surveys
- Creator:
- Hana Rosolová, Barbora Nussbaumerová, Otto Mayer, Renata Cífková, and Jan Bruthans
- Format:
- print, bez média, and svazek
- Type:
- article, články, journal articles, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, kardiovaskulární nemoci, prevence onemocnění, cardiovascular diseases, prevention of diseases, cardiovascular prevention, coronary heart disease, residual risk, 14, and 612
- Language:
- English
- Description:
- Cardiovascular (CV) mortality was reduced more than 50 % in the Czech population at the turn of the century, due to an improvement of major CV risk factors in the general population, interventional procedures implemented into the treatment of acute coronar y events, and new drugs (ACE inhibitors, statins etc.) for CV prevention (Czech MONICA and post-MONICA studies, 1985-2008). An insufficient level of preventive efforts is described in the Czech patients after acute coronary syndrome (Czech part of the EURO ASPIRE studies, 1995-2013). Drug underdosing and wrong patients’ compliance to life style and drug therapy recommendations represent two main reasons of this unsatisfactory situation. The residual vascular risk of patients with stable coronary heart diseas e (CHD) is still high due to a poor control of conventional risk factors on the one hand, and due to increasing weight and glucose metabolism abnormalities on the other hand. Patients with insulin resistance and glucose dis orders have more frequently non-LDL-C dyslipidemia (atherogenic dyslipidemia), hypertriglyceridemic waist and high atherogenic index of plasma (AIP>0.24), i.e. markers of residual CV risk. Among others increased dose of statins and combined lipid modifying therapy should be implemented in patients with CHD, diabetes or metabolic syndrome., H. Rosolová, B. Nussbaumerová, O. Mayer Jr., R. Cífková, J. Bruthans., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1489. Sudden cardiac death thirty years ago and at present. The role of autonomic disturbances in acute myocardial infarction revisited
- Creator:
- Pokorný, J., Vladimír Staněk, and Milan Vrána
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, náhlá smrt, prevence onemocnění, sudden death, prevention of diseases, myocardial ischemia, ventricular fibrillation, autonomic disturbances, 14, and 612
- Language:
- English
- Description:
- The most common cause of sudden cardiac death is ventricular fibrillation (VF). In addition to the status, size and location of the ventricular focus, a major pathogenic mechanism triggering VF is autonomic dysbalance (d isturbance). This term refers to a wide range of reflex changes in the ratio of sympathetic to vagal ventricular activation over time, occurring immediately after coronary artery occlusion at the onset of acute myocardial infarction (AMI). Another trigger of VF is autonomic disturbance due to emotional stress. Experimental and clinical research into autonomic disturbances associated with coronary artery occlusion and emotional stress was given considerable attention as early as some 30 years ago when researchers were already searching for ways of inhibiting autonomic disturbances using predominant sympathetic and vagal activation by beta-blockers (BB) and atropine, respectively. The aim of our paper is to compare results obtained 30 years ago with current status of experimental and clinical research into SCD preven tion. Another aim is to identify questions that have remained unanswered to date; answers to these outstanding questions could help further reduce the risk of SCD., J. Pokorný, V. Staněk, M. Vrána., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1490. Supplemented creatine induces changes in human metabolism of thiocompounds and one- and two-carbon units
- Creator:
- Tomáš Navrátil, Eva Kohlíková, Miroslav Petr, Daniela Pelclová, Michael Heyrovský, and Kamila Přistoupilová
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, kreatinin, foláty, homocystein, voltametrie, moč, krev, creatinine, folates, homocysteine, voltammetry, urine, blood, creatine, vitamin B12, thiodiglycolic acid (TDGA), 14, and 612
- Language:
- English
- Description:
- The administration of creatine (5 g/day for one month) to 11 young active sportsmen affected their urinary excretion of creatine, creatinine, and thiodiglycolic acid (TDGA) as well as blood levels of homocysteine, vitamin B12 and folates. The probands were divided into four groups, according to the amount of creatine found in urine, and of folates and vitamin B12 determined in blood. The changes of folates and vitamin B12 were mutually reciprocal. Each group utilized CR as donor of one- and two-carbon (1C and 2C) units by means of homocysteine (HoCySH), folates, and vitamin B12, in different metabolic pathways. In 10 men the creatine administration was accompanied by an increase of HoCySH level in blood, while in the last man, with accidentally discovered hyperhomocysteinemia, the HoCySH level dropped by 50 %. Differences between initial and terminal TDGA levels indicate that creatine affects equilibria of redox processes. Creatinine excretion into urine changed in the dependence on the extent of metabolic disturbances., T. Navrátil ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public