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332. The effects of 17β estradiol, 17α estradiol and progesterone on oxidative atress biomarkers in ovariectomized female rat brain subjected to global cerebral ischemia
- Creator:
- Ozacmak, V. H. and Sayan, H.
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, progesteron, mozková ischemie, oxidační stres, physiology, progesterone, brain ischemia, oxidative stress, estradiol, 14, and 612
- Language:
- English
- Description:
- Neuroprotective effects of estrogens and progesterone have been widely studied in various experimental models. The present study was designed to compare possible neuroprotective effects of 17alpha-estradiol, 17beta-estradiol, and progesterone on oxidative stress in rats subjecte d to global cerebral ischemia. Global cerebral ischemia was induced in ovariectomized female rats by four vessel occlusion for 10 min. Following 72 h of reperfusion, levels of malondialdehyde (MDA, oxidative stress marker), and reduced glutathione (GSH, major endogenous antioxidant) were assessed in hippocampus, striatum and cortex of rats treated with either 17alpha-estradiol, 17beta-estradiol, progesterone or estradiol + progesterone beforehand. Steroid administration ameliorated ischemia-induced decrease in GSH and increase in MDA levels. Our data offers additional evidence that estrogens and progesterone or combination of two exert a remarkable neuroprotective effect reducing oxidative stress., V. H. Ozacmak, H. Sayan., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
333. The effects of head cooling on endurance and neuroendocrine responses to exercise in warm conditions
- Creator:
- Ansley, L., Marvin, G., Sharma, A., Kendall, M. J., Jones, D. A., and Bridge, M. W.
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, hypertermie, tělesná cvičení, únava, physiology, hyperthermia, exercises, fatigue, prolactin, head cooling, 14, and 612
- Language:
- English
- Description:
- The present study investigated the effects of head cooling during endurance cycling on performance and the serotonergic neuroendocrine response to exercise in the heat. Subjects exercised at 75 % VO2max to volitional fatigue on a cycle ergometer at an ambient temperature of 29±1.0 °C, with a relative humidity of approximately 50 %. Head cooling resulted in a 51 % (p<0.01) improvement in exercise time to fatigue and Borg Scale ratings of perceived exertion were significantly lower throughout the exercise period with cooling (p<0.01). There were no indications of peripheral mechanisms of fatigue either with, or without, head cooling, indicating the importance of central mechanisms. Exercise in the heat caused the release of prolactin in response to the rise in rectal temperature. Head cooling largely abolished the prolactin response while having no effect on rectal temperature. Tympanic temperature and sinus skin temperature were reduced by head cooling and remained low throughout the exercise. It is suggested that there is a co-ordinated response to exercise involving thermoregulation, neuroendocrine secretion and behavioural adaptations that may originate in the hypothalamus or associated areas of the brain. Our results are consistent with the effects of head cooling being mediated by both direct cooling of the brain and modified cerebral artery blood flow, but an action of peripheral thermoreceptors cannot be excluded., L. Ansley, G. Marvin, A. Sharma, M. J. Kendall, D. A. Jones, M. W. Bridge., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
334. The effects of lidocaine on bupivacaine-induced cardiotoxicity in the isolated rat heart
- Creator:
- Ivo Křikava, Jiří Jarkovský, Pavel Štourač, Marie Nováková, and Pavel Ševčík
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, bupivacaine, lidocaine, isolated rat heart, cardiotoxicity, QRS duration, 14, and 612
- Language:
- English
- Description:
- Bupivacaine is a widely used long-acting local anaesthetic. In clinical practice, a mixture of bupivacaine and lidocaine is often used in order to combine the faster onset of sensory blockade of lidocaine with more profound and longer duration of blockade by bupivacaine. The aim of this study was to compare the cardiotoxicity of large doses of bupivacaine and mixture of bupivacaine with lidocaine in the isolated rat heart and to estimate whether or not the addition of lidocaine in clinically relevant concentration increases bupivacaine-induced toxicity. Experiments were performed on 21 adult male rats divided into three groups: B (6 μg/ml bupivacaine), BL (6 μg/ml bupivacaine and 12 μg/ml lidocaine) and L (12 μg/ml lidocaine). The experiment consisted of three 30 min periods: stabilisation, perfusion and washout. The isolated hearts were perfused according to Langendorff with Krebs-Henseleit solution at constant pressure (80 mmHg) and 37 °C (CaCl2 1.25 mM) and the heart rate (based on RR interval assessment), PQ and QRS intervals were measured. The present study shows that the mixture of tested anaesthetics - bupivacaine and lidocaine - impairs the intraventricular conduction parameters (QRS interval prolongation) to a lesser extent than bupivacaine itself, and that this effect is marked mainly at the beginning of perfusion., I. Křikava ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
335. The effects of pertussis toxin-treatment on integrated vasoactive response of vascular system in spontaneously hypertensive rats
- Creator:
- Soňa Čačányiová, Kristek, F., Jaroslav Kuneš, and Josef Zicha
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, krevní tlak, acetylcholin, physiology, blood pressure, acetylcholine, spontaneously hypertensive rats (SHR), pertussis toxin, noradrenaline, bradykinin, vasoactive responses, 14, and 612
- Language:
- English
- Description:
- We investigated the effect of pertussis toxin (PTX) on hypotensive response induced by acetylcholine (ACh) and bradykinin (BK) and on noradrenaline (NA)-induced pressor response in spontaneously hypertensive rats (SHR). Fifteen-week-old Wistar rats and age-matched SHR were used. Half of SHR received PTX (10 μg/kg/i.v.) and the experiments were performed 48 h later. After the anesthesia the right carotid artery was cannulated in order to record blood pressure (BP). The hypotensive response to ACh was enhanced in SHR compared to Wistar rats. After pretreatment of SHR with PTX the hypotensive response to ACh was reduced compared to untreated SHR and it was also diminished in comparison to Wistar rats. Similarly, the hypotensive response to BK was also decreased after PTX pretreatment. The pressor response to NA was increased in SHR compared to Wistar rats. NA-induced pressor response was considerably decreased after PTX pretreatment compared to untreated SHR. In conclusion, the enhancement of hypotensive and pressor responses in SHR was abolished after PTX pretreatment. Our results suggested that the activation of PTX-sensitive inhibitory Gi proteins is involved in the regulation of integrated vasoactive responses in SHR and PTX pretreatment could be effectively used for modification of BP regulation in this type of experimental hypertension., S. Čačányiová, F. Kristek, J. Kuneš, J. Zicha., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
336. The influence of monovalent cations on trimeric G protein Gi1α activity in HEK293 cells stably expressing DOR-Gi1α (Cys351-Ile351) fusion protein
- Creator:
- Vošahlíková, M. and Petr Svoboda
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, δ-opioid receptor (DOR), monovalent ions, Gi1α protein, 14, and 612
- Language:
- English
- Description:
- The effect of monovalent cations on trimeric G protein Gi1α was measured at equimolar concentration of chloride anion in pertussis-toxin (PTX)-treated HEK293 cells stably expressing PTX- insensitive DOR-Gi1α (Cys351-Ile351) fusion protein by high-affinity [35S]GTPγS binding assay. The high basal level of binding was detected in absence of DOR ag onist and monovalent ions and this high level was inhibited with the order of: Na+>K+>Li+. The first significant inhibition was detected at 1 mM NaCl. The inhibition by monovalent ions was reversed by increasing concentrations of DOR agonist DADLE. The maximum DADLE response was also highest for sodium and decreased in the order of: Na+>K+≈Li+. Our data indicate i) an inherently high activity of trimeric G protein G i 1 α when expressed within DOR-Gi1α fusion protein and determined in the absence of monovalent cations, ii) preferential sensitivity of DOR-Gi1α to sodium as far as maximum of agonist response is involved., M. Vošahlíková, P. Svoboda., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
337. The interaction of genetic and environmental factors in the etiology of hypertension
- Creator:
- Jaroslav Kuneš and Josef Zicha
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, syndrom inzulinové rezistence, hypertenze, geny, životní prostředí, ekologická genetika, physiology, insulin resistance syndrome, hypertension, genes, environment, ecological genetics, 14, and 612
- Language:
- English
- Description:
- Essential hypertension is a major risk factor for several cardiovascular diseases. It is a complex trait resulting from the interactions of multiple genetic and environmental factors. Moreover, not only genetic but also epigenetic inheritance plays a significant role. One can speculate that hypertension develops as a consequence of “errors” in well-coordinated regulatory systems of blood pressure. Errors in the cascade of molecular, biochemical and genetic processes, which regulate blood pressure, have finally enough potential to result in hypertension. Numerous environmental factors surrounding the organism during its development should influence the expression of genetic information. However, despite the considerable research effort, it is still difficult to identify all genes and/or other genetic determinants leading to essential hypertension and other cardiovascular diseases. This is mainly because these diseases usually become a medical problem in adulthood, although their roots might be traced back to earlier stages of ontogeny. The link between distinct developmental periods (e.g. birth and adulthood) should involve changes in gene expression involving epigenetic phenomena. The purpose of the present paper is to bring a piece of light on gene-environmental interactions potentially implicated in the pathogenesis of hypertension., J. Kuneš, J. Zicha., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
338. The NADPH oxidase inhibitors iodonium diphenyl and cadmium sulphate inhibit hypoxic pulmonary vasoconstriction in isolated rat pulmonary arteries
- Creator:
- Jones, R. D., Thompson, J. S., and Alyn H. Morice
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, NADPH oxidase, hypoxic pulmonary vasoconstriction, iodonium diphenyl cadmium sulphate, isolated rat pulmonary artery, 14, and 612
- Language:
- English
- Description:
- Interest surrounds the role of an NADPH oxidase-like enzyme in hypoxic pulmonary vasoconstriction (HPV). We have studied the effects of the NADPH oxidase inhibitors iodonium diphenyl (ID) and cadmium sulphate (CdSO4) upon HPV of isolated rat pulmonary arteries (n = 73, internal diameter 545± 23 mm). Vessels were preconstricted with prostaglandin F2a (PGF2a, 0.5 or 5 mM) prior to a hypoxic challenge. ID (10 or 50 mM), CdSO4 (100 mM) or vehicle (50 ml) was added for 30 min before re-exposure to PGF2a and hypoxia. ID and CdSO4 significantly inhibited HPV. In vessels preconstricted with 5 mM PGF2a, ID (10 and 50 mM) reduced HPV from 37.4± 5.6 % to 9.67± 4.4 % of the contractile response elicited by 80 mM KCl (P<0.05) and from 30.1± 5.0 % to 0.63± 0.6% 80 mM KCl response (P<0.01), respectively. CdSO4 (100 mM) reduced HPV from 29.4±4.0 % to 17.1±2.2% 80 mM KCl response (P<0.05). In vessels preconstricted with 0.5 mM PGF2a, ID (10 and 50 mM) reduced HPV from 16.0± 3.15% to 3.36± 1.44 % 80 mM KCl response (P<0.01) and from 15.0± 1.67 % to 2.82± 1.40 % 80 mM KCl response (P<0.001), respectively. Constriction to PGF2a was potentiated by ID. ID and CdSO4, at concentrations previously shown to inhibit neutrophil NADPH oxidase, attenuate HPV in isolated rat pulmonary arteries. This suggests that an NADPH oxidase-like enzyme is involved in HPV and could act as the pulmonary oxygen sensor., R. D. Jones, J. S. Thompson, A. H. Morice., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
339. The origin of 7α-hydroxy-dehydroepiandrosterone and its physiological role: a history of discoveries
- Creator:
- Luboslav Stárka
- Format:
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- Type:
- article, články, journal articles, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, 11β-hydroxysteroid dehydrogenase, CYP7B, immunomodulatory effects, occurrence, dehydroepiandrosterone, 7α-hydroxy-dehydroepiandrosterone, neurosteroid, 14, and 612
- Language:
- English
- Description:
- Nearly 60 years has elapsed since the first isolation and identification of 7α-hydroxy-dehydroepiandrosterone, and in that time much information has been gained on its occurrence, metabolism, ontogeny, immunomodulatory activity, cell proliferation, cortisol control in local tissues and neuroactivity. Additional knowledge about this steroid may elucidate its role in obesity, neurodegenerative disturbances such as Alzheimer’s disease, or psychiatric disorders such as schizophrenia or depression. This review aims to provide a comprehensive summary of the available literature on 7α-hydroxydehydroepiandrosterone., L. Stárka., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
340. The pacemaker activity of interstitial cells of Cajal and gastric electrical activity
- Creator:
- Petra Čamborová, Hubka, P., Igor Šulla, and Ivan Hulín
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, interstitial cells of Cajal, gastric electrical activity, pacemaker of the stomach, kit-receptor, electrogastrography, 14, and 612
- Language:
- English
- Description:
- Interstitial cells of Cajal (ICC) are the pacemaker cells in the gut. They have special properties that make them unique in their ability to generate and propagate slow waves in gastrointestinal muscles. The electrical slow wave activity determines the characteristic frequency of phasic contractions of the stomach, intestine and colon. Slow waves also determine the direction and velocity of propagation of peristaltic activity, in concert with the enteric nervous system. Characterization of receptors and ion channels in the ICC membrane is under way, and manipulation of slow wave activity markedly alters the movement of contents through the gut. Gastric myoelectrical slow wave activity produced by pacemaker cells (ICC) can be reflected by electrogastrography (EGG). Electrogastrography is a perspective non-invasive method that can detect gastric dysrhythmias associated with symptoms of nausea or delayed gastric emptying., P. Čamborová, P. Hubka, I. Sulková, I. Hulín., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public