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Start Over Subject Fyziologie člověka a srovnávací fyziologie Date Unknown

1362. Signs of myelin impairment in cerebrospinal fluid after osmotic opening of the blood-brain barrier in rats

Creator:
Petr Kozler, Ondřej Sobek, and Pokorný, J.
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Fyziologie člověka a srovnávací fyziologie, mozkomíšní mok, hematoencefalická bariéra, cerebrospinal fluid, blood-brain barrier, myelin basic protein, CSF sampling, osmotic BBB disruption, 14, and 612
Language:
English
Description:
A number of clinical neurological pathologies are associated with increased permeability of the blood brain barrier (BBB). Induced changes of the homeostatic mechanisms in the brain microenvironment lead among others to cellular changes in the CNS. The question was whether some of these changes can be induced by osmotic opening of BBB in an in vivo experiment and whether they can be detected in cerebrospinal fluid (CSF). CSF was taken via the suboccipital puncture from 10 healthy rats and six rats after the osmotic opening of the BBB. In all 16 animals, concentration of myelin basic protein (MBP ng/ml), Neuron-specific enolase (NSE ng/ml) and Tau-protein (Tau pg/ml) were determined in CSF by ELISA. Values in both groups were statistically evaluated. Significant difference between the control and experimental group was revealed only for the concentration of myelin basic protein (p<0.01). The presented results indicate that osmotic opening of the BBB in vivo experiment without the presence of other pathological conditions of the brain leads to a damage of myelin, without impairment of neurons or their axons., P. Kozler, O. Sobek, J. Pokorný., and Obsahuje bibliografii
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1363. Sildenafil is more selective pulmonary vasodilator than prostaglandin E1 in patients with pulmonary hypertension due to heart failure

Creator:
Hikmet Al-Hiti, Vojtěch Melenovský, Petr Syrovátka, Jiří Kettner, Ivan Málek, and Josef Kautzner
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Subject:
Fyziologie člověka a srovnávací fyziologie, srdeční selhání, hemodynamika, prostaglandiny, heart failure, hemodynamics, prostaglandins, pulmonary vascular resistance, sildenafil, prostaglandin E1, 14, and 612
Language:
English
Description:
In some patients, heart failure (HF) is associated with increased pulmonary vascular resistance (PVR). The magnitude and the reversibility of PVR elevation affect the HF management. Sildenafil has been recently recognized as potent PVR-lowering drug in HF. The aim of the study was to compare hemodynamic effects and pulmonary selectivity of sildenafil to prostaglandin E1(PGE1). Right-heart catheterization was performed in 13 euvolemic advanced HF patien ts with elevated PVR (6.3±2 Wood's units). Hemodynamic parameters were measured at the baseline, during i.v. infusion of PGE1 (alprostadil 200 ng·kg-1·min-1 ) and after 40 mg oral do se of sildenafil. Both drugs similarly reduced systemic vascular resistance (SVR), but sildenafil had higher effect on PVR (-28 % vs. -49 %, p=0.05) and transpulmonary pressu re gradient than PGE1. The PVR/SVR ratio - an index of pulmonary se lectivity, did not change after PGE1(p=0.7) but it decreased by -32 % (p=0.004) after sildenafil. Both drugs similarly reduced pulmonary artery mean and wedge pressures and increa sed cardiac index (+27 % and +28 %). Sildenafil led more often to transplant-acceptable PVR while causing smaller drop of mean systemic pressure than PGE1. In conclusion, vasodilatatory effects of sildenafil in patients with heart failure are more pronounced in pulmonary than in systemic circulation., H. Al-Hiti ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
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1364. 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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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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1365. Similar effects of lamotrigine and phenytoin against cortical epileptic foci in immature rats

Creator:
Klára Bernášková and Pavel Mareš
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Subject:
Fyziologie člověka a srovnávací fyziologie, mozková kůra, cerebral cortex, epileptic focus, bicuculline methiodide, immature rat, antiepileptic drugs, 14, and 612
Language:
English
Description:
Action of antiepileptic drugs in immature brain may differ from that in adult brain. The aim of our study was to study an anticonvulsant action of lamotrigine and phenytoin, i.e. two drugs active against partial seizures in adult experimental animals as well as human patients, in a model of simple partial seizures in immature rats. Epileptic foci were induced by local application of bicuculline methiodide on sensorimotor cortical area of 12-dayold rat pups. The animals were pretreated with lamotrigine (LTG, 10 or 20 mg/kg i.p.) or phenytoin (PHT, 15, 30 or 60 mg/kg i.p.). Control rats for LTG received saline, controls for PHT solvent composed of propyleneglycol, ethanol and water. Influence of either drug on interictal activity was negligible. High doses of both LTG and PHT suppressed the transition into ictal phases and shortened the duration of persisting seizures. The tricomponent solvent exhibited moderate activity against ictal activity if compared with saline controls. The two drugs exhibited similar action in our model, i.e. the suppression of secondary generalization from epileptic focus. This action is comparable to that described for human patients and adult experimental animals. In favor of lamotrigine speaks the absence of serious side effects., K. Bernášková, P. Mareš., and Obsahuje bibliografii a bibliografické odkazy
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1366. 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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1367. Simultaneous decrease of plasma obestatin and ghrelin levels after a high-carbohydrate breakfast in healthy women

Creator:
Dana Sedláčková, Ivana Dostálová, Vojtěch Hainer, Beranová, L., Hana Kvasničková, Martin Hill, Martin Haluzík, and Jara Nedvídková
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Fyziologie člověka a srovnávací fyziologie, endokrinologie, biochemie, endocrinology, biochemistry, obestatin, total ghrelin, acyl ghrelin, desacyl ghrelin, carbohydrate breakfast, 14, and 612
Language:
English
Description:
Ghrelin is a gut peptide produced mainly by stomach, well known to induce appetite stimulatory actions. Obestatin, a recently identified peptide derived from preproghrelin, was initially described to antagonize stimulatory effect of ghrelin on food intake. The postprandial response of obestatin and its relationship with ghrelin in humans remains unknown. We therefore investigated the postprandial response of obestatin and total ghrelin, acyl and desacyl ghrelin and neuropeptide Y (NPY) to a high-carbohydrate breakfast (1 604 kJ) in eight healthy women (age: 24.2±0.82 years; BMI 21.6±0.61 kg/m2). Blood samples were collected before the meal, and 30, 60, 90, 120 and 150 min after the breakfast consumption. Postprandial plasma obestatin concentrations significantly decreased compared with preprandial levels as well as total ghrelin concentrations and reached the lowest values 90 and 120 min after the meal consumption, respectively (p 0.05). Plasma acyl and desacyl ghrelin concentrations decreased after the breakfast and reached lowest values in 30 and 60 min, respectively (p<0.05). Plasma NPY concentrations were lower than preprandial levels 90 and 150 min after consuming breakfast (p<0.05). In conclusion, we demonstrated in healthy young women that plasma obestatin concentrations decrease similarly to ghrelin after a high-carbohydrate breakfast., D. Sedláčková, I. Dostálová, V. Hainer, L. Beranová, H. Kvasničková, M. Hill, M. Haluzík, J. Nedvídková., and Obsahuje bibliografii a bibliografické odkazy
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1368. Simvastatin alleviates myocardial contractile dysfunction and lethal ischemic injury in rat heart independent of cholesterol-lowering effects

Creator:
Adriana Adameová, Anna Harčárová, Jana Matejíková, Dezider Pancza, Magdaléna Kuželová, Slávka Čarnická, Peter Švec, Monika Barteková, Ján Styk, and Ravingerová, T.
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Subject:
Fyziologie člověka a srovnávací fyziologie, cholesterol, statiny, srdce, ischemie, statins, heart, ischemia, pleiotropic effects, 14, and 612
Language:
English
Description:
a1_Statins, the inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, are most frequently used drugs in the prevention of coronary artery disease due to their cholesterol- lowering activity. However, it is not exactly known whether these effects of statins or those independent of cholesterol decrease account for the protection ag ainst myocardial ischemia- reperfusion (I/R) injury. In this study, we investigated the effect of 5-day treatment with simvastatin (10 mg/kg) in Langendorff- perfused hearts of healthy control (C) and diabetic- hypercholesterolemic (D-H; strept ozotocin + high fat-cholesterol diet, 5 days) rats subjected to 30-min global ischemia followed by 40-min reperfusion for the examination of postischemic contractile dysfunction and reperfusion-induced ventricular arrhythmias or to 30-min (left anterior descending) coronary artery occlusion and 2-h reperfusion for the infarct size determination (IS; tetrazolium stai ning). Postischemic recovery of left ventricular developed pressu re (LVDP) in animals with D-H was improved by simvastatin therapy (62.7±18.2 % of preischemic values vs. 30.3±5.7 % in the untreated D-H; P<0.05), similar to the values in the simvastatin-treated C group, which were 2.5-fold higher than those in the untreated C group. No ventricular fibrillation occurred in the simvastatin-treated C and D-H animals during reperf usion. Likewise, simvastatin shortened the duration of ventri cular tachycardia (10.2±8.1 s and 57.8±29.3 s in C and D-H vs. 143.6±28.6 s and 159.3±44.3 s in untreated C and D-H, respectively, both P<0.05). The decreased arrhythmogenesis in the simvastatin-treated groups correlated with the limitation of IS (in % of risk area) by 66 % and 62 % in C and D-H groups, respectively. However, simvastatin treatment decreased plasma cholesterol levels neither in the D-H animals nor in C., a2_The results indicate that other effects of statins (independent of cholesterol lowering) are involved in the improvement of contractile recovery and attenuation of lethal I/R injury in both, healthy and diseased individuals., A. Adameová, A. Harčárová, J. Matejíková, D. Pancza, M. Kuželová, S. Čarnická, P. Švec, M. Barteková, J. Styk, T. Ravingerová., and Obsahuje bibliografii
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1369. Simvastatin decreased coenzyme Q in the left ventricle and skeletal muscle but not in the brain and liver in L-NAME-induced hypertension

Creator:
Jarmila Kucharská, Anna Gvozdjáková, and Fedor Šimko
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Fyziologie člověka a srovnávací fyziologie, hypertenze, hypertension, simvastatin, NO-deficient hypertension, tissue coenzyme Q, L_NAME, 14, and 612
Language:
English
Description:
Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase (statins) have been proven to reduce effectively cholesterol level and morbidity and mortality in patients with coronary heart disease and/or dyslipoproteinemia. Statins inhibit synthesis of mevalonate, a precursor of both cholesterol and coenzyme Q (CoQ). Inhibited biosynthesis of CoQ may be involved in some undesirable actions of statins. We investigated the effect of simvastatin on tissue CoQ concentrations in the rat model of NO-deficient hypertension induced by chronic L-NAME administration. Male Wistar rats were treated daily for 6 weeks with L-NAME (40 mg/kg) or with simvastatin (10 mg/kg), another group received simultaneously L-NAME and simvastatin in the same doses. Coenzyme Q9 and Q10 concentrations were analyzed by high performance liquid chromatography. L-NAME and simvastatin alone had no effect on CoQ concentrations. However, simultaneous application of L-NAME and simvastatin significantly decreased concentrations of both CoQ homologues in the left ventricle and slightly decreased CoQ9 concentration in the skeletal muscle. No effect was observed on CoQ level in the liver and brain. We conclude that the administration of simvastatin under the condition of NO-deficiency reduced the level of CoQ in the heart and skeletal muscle what may participate in adverse effect of statins under certain clinical conditions., J. Kucharská, A. Gvozdjáková, F. Šimko., and Obsahuje bibliografii
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1370. 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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Subject:
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
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