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82. Delayed effects of elevated corticosterone level on volume of hippocampal formation in laboratory rat
- Creator:
- Petr Zach, Mrzílková, J., Lenka Řezáčová, Aleš Stuchlík, and Karel Valeš
- Format:
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- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, corticosterone, hyppocampus, lateralization, volumetry, long evans rat, 14, and 612
- Language:
- English
- Description:
- We studied delayed effects of elevated plasma levels of corticosterone (Cort) on volumetry, neuronal quantity, and gross marks of neurodegeneration in the hippocampal formation of Long-Evans rats. Animals were exposed to increased CORT levels for three weeks via implanted subcutaneous pellets. Volumetry, neuronal quantification and gros s marks of degeneration were measured seven weeks after the termination of CORT treatment. We observed significant differences in volumes and especially in laterality of hippocampal subfields between control and CORT- treated animals. We found th at the left hippocampus was substantially larger than the right hippocampus in the corticosterone-treated group, but not in the control group. In the control group, on the other hand, right hippocampal volume was markedly higher than all other measured volumes (hippocampal left control, hippocampal left CORT-treated and hippocampal right CORT-treated). Left hippocampal volume did not differ between the groups., P. Zach, J. Mrzílková, L. Řezáčová, A. Stuchlík, K. Valeš., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
83. Depressed cardiac contractility and its postnatal development in rats after chemical sympathectomy
- Creator:
- Jitka Švíglerová, Jitka Kuncová, Lukáš Nalos, Jana Slavíková, and Milan Štengl
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- Type:
- article, články, model:article, and TEXT
- Subject:
- Biochemie. Molekulární biologie. Biofyzika, fyziologie, neuropeptidy, srdce, potkan, physiology, neuropeptids, heart, Rattus norvegicus, chemical sympathectomy, contraction, norepinephrine, 2, and 577
- Language:
- English
- Description:
- This study sought to evaluate whether consumption of polyphenol extract from Cognac (CPC) modulates platelet activation and cardiovascular reactivity in rats. Male Wistar rats were treated daily for 4 weeks by intra-gastric gavage receiving CPC at 80 mg/kg/day or vehicle (5 % glucose). Platelet adhesion and aggregation in response to different activators were assessed. Cardiac and vascular reactivity in response to various agonists as well as NO measurement by electron paramagnetic resonance technique were investigated in isolated heart and thoracic aorta. Oral administration of CPC decreased platelet aggregation induced by ADP but not by collagen. CPC did not affect adhesion to collagen. The chronotropic but not the inotropic response to isoprenaline was reduced without alteration of NO production in hearts from CPC-treated rats. CPC treatment did not affect ex vivo relaxation to acetylcholine nor NO content of rat aorta. CPC did not significantly alter the response to phenylephrine in aorta despite the participation of endothelial vasoconstrictor products. In summary, chronic treatment with CPC has no impact on ex vivo vascular and cardiac reactivity; however, it reduced heart work and platelet aggregation. These data suggest the existence of compounds in Cognac that may decrease the risk of coronary thrombosis and protect against some cardiac diseases., J. Švíglerová, J. Kuncová, L. Nalos, J. Slavíková, M. Štengl., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
84. Depression and/or potentiation of cortical responses after status epilepticus in immature rats
- Creator:
- Grigorij Tsenov and Pavel Mareš
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- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, epilepsie, ontogeneze, potkan, physiology, epilepsy, ontogeny, Rattus norvegicus, status epilepticus, evoked potentials, frequency depression, 14, and 612
- Language:
- English
- Description:
- Lithium-pilocarpine status epilepticus (SE) resulted in delayed changes of single cortical in terhemisperic (transcallosal) responses in immature rats. Low-frequency stimulation inducing depression and/or potentiation was studied to analyze possible dynamic changes in cortical responses. Status was elicited in 12-day-old (SE12) or 25-day-old (SE25) rats. Control siblings received saline instead of pilocarpine. Interhemispheric responses were elicited by stimulation of the sensorimotor region of the cerebral cortex 3, 6, 9, 13, or 26 days after status. A series of 5 biphasic pulses with intensity equal to twofold threshold were used for stimulation. The interval between pulses was 100, 125, 160, 200 or 300 ms, eight responses were always averaged. Peak amplitude of the first positive, first negative and second positive waves was measured and responses to the second, third, fourth and fifth pulse were compared with the first one. Animals after status epilepticus as well as lithium-paraldehyde controls exhibit a frequency depression at nearly all the intervals studied. An outlined increase of responses in SE rats in comparison with the controls three days after SE stayed just below the level of statistical significance. In addition, animals in the SE12 group exhibited potentiation of responses at this interval after SE. With longer intervals after SE, the relation between SE and control animals changed twice resulting in a tendency to lower amplitude of responses in SE than in control rats 26 days after SE. Rats in the SE25 group exhibited higher responses than controls 13 days after status, but this difference was not present at the longest interval after SE. Low-frequency stimulation did not reveal increased cortical excitability as a long-lasting consequence of status epilepticus induced in immature rats. In addition, the outlined differences between SE and control rats changed with the time after SE., G. Tsenov, P. Mareš., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
85. Detection and possible role of proteasomes in the bronchoalveolar space of the injured lung
- Creator:
- Majetschak, M., Sorell, L. T., Patricelli, T., Seitz, D. H., and Knöferl, M. W.
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- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, 26S proteasome, 20S core particle, 19S regulator complex, ubiquitin, ubiquitin-protein ligase, 14, and 612
- Language:
- English
- Description:
- Recent observations suggest the presence of 20S proteasomes (20S) in the lung epithelial lining fluid. However, the physiological relevance of 20S in the alveolar space and possible contribution to disease processes are unknown. Thus, we evaluated whether extracellular proteasomes could have a pathophysiological role in the injured lung using a rat model of lung contusion (LC). Bronchoalveolar lavage fluids (BALF) were obtained at various time points for up to 168 h after LC or sham procedure. Enzyme activities, ELISA and Western blots indicated enzymatically active 20S, the 19S subunit Rpt5 and ubiquitin in BALF. 20S and ubiquitin increased significantl y after LC, peaked at 24 h and normalized within 168 h. Mg 2+ /ATP-dependent peptidase activities were detectable 6-24 h after LC. BALF after LC also contained ubiquitin-protein-ligase activity. Addition of Mg 2+ /ATP to BALF after LC led to significant proteolysis and could be prevented with epoxomicin and EDTA. These data suggest for the first time that the Mg 2+ /ATP-dependent 26S proteasome complex exists outside the cell, is released into the lung epithelial lining fluid after LC and contribute s to the proteolysis of the bulk of protein in the alveolar space of the injured lung. We infer that proteasome complexes may have a pathophysiological role during lung edema clearance., M. Majetschak, L. T. Sorell, T. Patricelli, D. H. Seitz, M. W. Knöferl., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
86. Detrimental subtype-specific endothelin-1 (ET-1) signaling in myocardial cells: the ET(A) mediated proliferation and ET(B) receptor down-regulation
- Creator:
- Ján Dřímal, Mislovičová, M., Ismail, A., and Monček, F.
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- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, ligand binding, endothelin-1, photoaffinity labeling, Ca2+ channels, human fibroblasts, porcine myocardium, microsomal membranes, rat renal hypertension, 14, and 612
- Language:
- English
- Description:
- Many physiological and pathological processes in the cardiac tissue have been shown to be associated with a release of endothelin (ET) peptides and with induction of specific ET-receptors and G-protein-coupled ion channels. However, the exact mechanism regulating ET-receptors in the myocardium is controversial. The response to ET-1, the most important member of the ET family, is rapidly attenuated by down-regulation of ET-receptors. The internalization of ET-1 bound to two subclasses of specific receptors (ETA and ETB) that are abundant in the myocardium has been hypothesized to activate and/or inhibit a variety of intracellular signal transducing systems. The [125I]ET-1, BQ-3020 and selective ET-antagonists were used to study the subtype-selective component of regulation of ET-1 receptors in myocardial membranes. We determined the characteristics of [125I]ET-1 binding and [3H]thymidine incorporation in whole cell saturation studies and measured Ca 2+ channel induction and the total number of inactive Ca2+ channels in photoaffinity studies with [3H]azidopine. Here we demonstrate four important components of the complex ET-1 response in human, porcine and rat myocardium, leading to aberrant responses of cells. After ET-1 induction, adaptive subtype-ETB selective down-regulation predominated in human embryonic fibroblasts, in porcine membrane vesicles and in microsomal membranes of renal hypertensive rats, with preferential high affinity ET-1 binding to ETA receptors and with the resultant ETA mediated proliferative and mitogenic activation of human fibroblasts. The ET-1 induction was also accompanied by profound inactivation of Ca2+ channels in myocardial membranes., J. Dřímal, M. Mislovičová, A. Ismail, F. Monček., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
87. Diabetes and thyroid hormones affect connexin-43 and PKC-ε expression in rat heart atria
- Creator:
- Mitašíková, M., Lin, H., Tomáš Soukup, Imanaga, I., and Narcisa Tribulová
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, srdeční síně, fibrilace síní, diabetologie, physiology, atria of heart, atrial fibrillation, diabetology, connexin-43, PKC-ε, rat heart atria, triiodothyronine, 14, and 612
- Language:
- English
- Description:
- We have examined the changes of intercellular electrical coupling protein connexin-43 (Cx43) and of PKC-ε in heart atria of diabetic rats and/or after the treatment with triiodothyronine (T3 ). Diabetes was induced in Wistar-Kyoto rats by streptozotocin (50 mg/kg, i.v.) and atria were examined after 5 (acute stage) and 10 (chronic stage) weeks. T 3 (10 μg/100 g/day) was applied via a gastric tube for the last 10 days prior to the end of the experiments to non-diabetic and to the half of diabetic rats. Expression and phosphorylated status of Cx43, as well as expression of PKC-ε , were analyzed by Western blots using mouse monoclonal anti-Cx43 and rabbit polyclonal anti-PKC-ε antibodies. We found that the Cx43 expression was significantly increased after the treatment with T3 and in the acute diabetes. Both in diabetes and after T3 treatment the phosphorylation of Cx43 isoforms was markedly suppressed compared to the non-diabetic and T3-untreated controls. Such a down-regulation was less pronounced in diabetic rats after the T3-treatment. The expression of atrial PKC-ε was increased in diabetic rats. This increase was suppressed after T3 administration and the expression was decreased in T3-treated non-diabetic rats. We suggest that the reduced Cx43 phosphorylation in diabetic and hyperthyroid rats can deteriorate a cell-to-cell coupling and consequently facilitate a development of atrial tachyarrhythmia in diabetic or hyperthyroid animals., M. Mitašíková ... [et al.]., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
88. Diagnostic significance of urinary thiodiglycolic acid as a possible tool for studying the role of vitamins B12 and folates in the metabolism of thiolic substances
- Creator:
- Tomáš Navrátil, Miroslav Petr, Zdeňka Šenholdová, Kamila Přistoupilová, Tomáš Ivan Přistoupil, Michael Heyrovský, Daniela Pelclová, and Eva Kohlíková
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- Type:
- article, články, model:article, and TEXT
- Subject:
- Biochemie. Molekulární biologie. Biofyzika, fyziologie, homocystein, moč, voltametrie, vitaminy skupiny B, foláty, human physiology, homocysteine, urine, voltammetry, vitamin B complex, folates, betain, kyselina thiodiglykolová, betaine, thiodiglycolic acid, 2, and 577
- Language:
- English
- Description:
- We have found that the determination of thiodiglycolic acid (TDGA) in urine may help to characterize metabolic imbalance of substances participating in methionine synthesis, which leads to hyperhomocystinuria. From the metabolic scheme, based on a proper combination of known facts, we attempted to theoretically explain and to demonstrate the possibilities of TDGA formation via different ways of homocysteine transformation. This scheme was used in evaluating the results obtained by testing urine of a woman suffering from impaired function of methionine synthase reductase (CblE type of homocystinuria). The amount of TDGA excreted in her morning urine was very sensitive to the changes in her treatment based upon a combination of N5-formyl tetrahydrofolate, betaine and vitamin B12. Vitamin B12 given in the evening either alone or together with betaine increased the TDGA excretion in the morning urine up to ten times. On the other hand, in the absence of vitamin B12, betaine in combination with N5-formyl tetrahydrofolate hindered the appearance of TDGA in the morning urine. Generally, the determination of TDGA in urine of an appropriately pretreated patient may indicate the degree of success of the treatment., T. Navrátil, M. Petr, Z. Šenholdová, K. Přistoupilová, T. I. Přistoupil, M. Heyrovský, D. Pelclová, E. Kohlíková., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
89. Different sensitivity of miniature endplate currents in rat external and internal intercostal muscles to the acetylcholinesterase inhibitor C-547 as compared with diaphragm and extensor digitorum longus
- Creator:
- Petrov, K., Kovyazina, I., Zobov, V., Bukharaeva, E., Nikolsky, E. E., and František Vyskočil
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, kosterní svaly, acetylcholin, physiology, striated muscles, acetylcholine, miniature endplate current, acetylcholinesterase, anticholinesterase, 14, and 612
- Language:
- English
- Description:
- Derivative of 6-methyluracil, selective cholinesterase inhibitor C-547 potentiates miniature endplate currents (MEPCs) in rat external intercostal muscles (external ICM) more effectively than in internal intercostal muscles (internal ICM). Effect of the C-547 on intercostal muscles was compared with those on extensor digitorum longus (EDL) and diaphragm muscles. Half-effective concentrations for τ of MEPC decay arranged in increasing order were as follows: EDL, locomotor muscle, most sensitive = 1.3 nM, external ICM, inspiration muscle = 6.8 nM, diaphragm, main inspiration muscle = 28 nM, internal ICM, expiration muscle = 71 nM. External ICM might therefore be inhibited, similarly as the limb muscles, by nanomolar concentrations of the drug and do not participate in inspiration in the presence of the C-547. Moreover, internal ICM inhibition can hinder the expiration during exercise-induced fast breathing of C-547-treated experimental animals., K. Petrov ... [et al.]., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
90. Differential expression of VEGFA, TIE2, and ANG2 but not ADAMTS1 in rat mesenteric microvascular arteries and veins
- Creator:
- Mecha Disassa, N., Styp-Rekowska, B., Hinz, B., Da Silva-Azevedo, L., Pries, A. R., and Zakrzewicz, Andreas
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, endotel, růstové faktory, physiology, endothelium, growth factors, microcirculation, vascular endothelial growth factor A, receptor TIE2, angiopoietin-2, 14, and 612
- Language:
- English
- Description:
- Microvessels respond to metabolic stimuli (e.g. pO2) and hemodynamic forces (e.g. shear stress and wall stress) with structural adaptations including angiogenesis, remodeling and pruning. These responses could be mediated by differential gene expression in endothelial and smooth muscle cells. Therefore, rat mesenteric arteries and veins we reexcised by microsurgery, and mRNA expression of four angioadaptation-related genes was quantified by real time duplex RT-PCR in equal amounts of total RNA, correlated to two different house keeping genes (ß-actin, GAPDH). The results show higher expression of VEGFA, TIE2, and ANG2 in arteries than in veins, but equal expression of ADAMTS1. Higher availability of VEGFA mRNA in endothelial cells of arteries shown here could contribute to the maintenance of mechanically stressed blood vessels and counteract pressure-induced vasoconstriction., N. Mecha Disassa ... [et al.]., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public