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453. Effect of 7-nitroindazole, a neuronal nitric oxide synthase inhibitor, on behavioral and physiological parameters

Creator:
Brožíčková, C., Anna Mikulecká, and Otáhal, J.
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Fyziologie člověka a srovnávací fyziologie, mozek, fyziologie, brain, physiology, 7-nitroindazole, open field test, ladder rung walking test, brain excitability, blood gas analysis, rat, 14, and 612
Language:
English
Description:
The role of brain derived nitric oxide in the physiology and behavior remains disputable. One of the reasons of the controversies might be systemic side effects of nitric oxide synthase inhibitors. Therefore, under nNOS inhibition by 7- nitroindazole (7-NI) we carried out recordings of blood gasses, blood pressure and spontaneous EEG in conscious adult rats. Locomotion and spontaneous behavior were assessed in an open field. In addition skilled walking and limb coordination were evaluated using a ladder rung walking test. The blood gas analysis revealed a significant increase in pCO2 180 min and 240 min after the application of 7-NI. The power and entropy decreased simultaneously with a shift of the mean frequency of the spontaneous EEG toward slow oscillations after 7-NI treatment. The thresholds of evoked potentials underwent a significant drop and a trend towards a slight increase in the I-O curve slope was observed. 7-NI significantly suppressed open field behavior expressed as distance moved, exploratory rearing and grooming. As for the ladder rung walking test the 7-NI treated animals had more errors in foot placement indicating impairment in limb coordination. Therefore our findings suggest that 7-NI increased cortical excitability and altered some physiological and behavioral parameters., C. Boržíčková, A. Mikulecká, J. Otáhal., and Obsahuje bibliografii
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http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

454. Effect of ACE inhibitor captopril and L-arginine on the metabolism and on ischemia-reperfusion injury of the isolated rat heart

Creator:
Jana Divišová, Hana Vavřínková, Milada Tutterová, Ludmila Kazdová, and Elena Meschišvili
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Subject:
Fyziologie člověka a srovnávací fyziologie, oxid dusnatý, ischemie, nitric oxide, ischemia, ACE inhibitors, L-arginine, isolated rat heart, ischemia-reperfusion injury, cyclic GMP, 14, and 612
Language:
English
Description:
We investigated the effects of in vivo treatment with the angiotensin-converting enzyme inhibitor (ACE-I) captopril and/or of in vitro administration of L-arginine on the metabolism and ischemia-reperfusion injury of the isolated perfused rat myocardium. Captopril (50 mg/l in drinking water, 4 weeks) raised the myocardial content of glycogen. After 25-min global ischemia, captopril treatment, compared with the controls, resulted in lower rates of lactate dehydrogenase release during reperfusion (8.58±1.12 vs. 13.39±1.88 U/heart/30 min, p<0.05), lower myocardial lactate contents (11.34±0.93 vs. 21.22±4.28 µmol/g d.w., p<0.05) and higher coronary flow recovery (by 25 %), and prevented the decrease of NO release into the perfusate during reperfusion. In control hearts L-arginine added to the perfusate (1 mmol/l) 10 min before ischemia had no effect on the parameters evaluated under our experimental conditions, presumably because of sufficient saturation of the myocardium with L-arginine. In the hearts of captopril-treated rats, L-arginine further increased NO production during reperfusion and the cGMP content before ischemia. Our results have shown that long-term captopril treatment increases the energy potential and has a beneficial effect on tolerance of the isolated heart to ischemia. L-arginine added into the perfusate potentiates the effect of captopril on the NO signaling pathway., J. Divišová, H. Vavřínková, M. Tutterová, L. Kazdová, E. Meschišvili., and Obsahuje bibliografii
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http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

455. Effect of acute and chronic simvastatin treatment on post-ischemic contractile dysfunction in isolated rat heart

Creator:
Ondrej Szárszoi, Jan Malý, Petr Ošťádal, Ivan Netuka, Josef Bešík, František Kolář, and Bohuslav Ošťádal
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Subject:
Experimentální medicína, fyziologie, kardiovaskulární nemoci, akutní stavy, physiology, cardiovascular diseases, acute states, simvastatin, isolated rat heart, ischemia/reperfusion injury, acute and chronic treatment, 14, and 616-092
Language:
English
Description:
Statins are powerful lipid-lowering drugs, widely used in patients with hyperlipidemia and coronary artery disease. It was found, however, that statins appear to have a pleiotropic effect beyond their lipid-lowering ability. They exert anti-inflammatory, antithrombotic and antioxidant effects, increase nitric oxide production and improve endothelial dysfunction. The aim of our study was to examine the effect of chronic and acute treatment with simvastatin on the contractile function of the isolated perfused rat heart after ischemia/reperfusion injury. Contractile function was measured on isolated rat hearts, perfused according to Langendorff under constant pressure. The hearts were subjected to 20 min of global ischemia, followed by 40 min of reperfusion. To investigate the acute effect, simvastatin at a concentration of 10 μmol/l was added to the perfusion solution during reperfusion. In chronic experiments the rats were fed simvastatin at a concentration of 10 mg/kg for two weeks before the measurement of the contractile function. Acute simvastatin administration significantly increased reparation of the peak of pressure development [(+dP/dt)max] (52.9±8.2 %) after global ischemia, as compared with the control group (28.8±5.2 %). Similar differences were also observed in the time course of the recovery of [(+dP/dt)max]. Chronic simvastatin was without any protective effect. Our results reveal that the acute administration of simvastatin during reperfusion, unlike the chronic treatment, significantly reduced contractile dysfunction induced by ischemia/reperfusion injury. This supports the idea of possible cardioprotective effect of statin administration in the first-line therapy of the acute coronary syndrome., O. Szárszoi, J. Malý, P. Ošťádal, I. Netuka, J. Bešík, F. Kolář, B. Ošťádal., and Obsahuje bibliografii a bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

456. Effect of acute hyperinsulinemia on brain metabolism evaluated by 1H MR spectroscopy - a pilot study

Creator:
Simona Kratochvílová, Antonín Škoch, Monika Dezortová, Švehlíková, E., Hill, M., Jana Brunová, Milan Hájek, and Terezie Pelikánová
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Subject:
Fyziologie člověka a srovnávací fyziologie, hyperinzulinémie, magnetická rezonanční spektroskopie, diabetes mellitus, hyperinsulinism, magnetic resonance spectroscopy, brain glucose metabolism, hyperinsulinemic clamp, type 1 diabetes, 14, and 612
Language:
English
Description:
To determine whether acutely-induced supraphysiological hyperinsulinemia influences brain metabolism in patients with type 1 diabetes (D) and healthy controls (C) as detected by MR Spectroscopy. Group D consisted of 4 patients with the average duration of diabetes for 7 years. They were matched according to age, sex and BMI to 4 healthy controls. 1H MR Spectroscopy was performed with a 1.5 Tesla. Spectra were obtained from parietooccipital white matter repeatedly during a 3-h hyperinsulinemic euglycemic clamp with 2 mU.kg-1.min-1. In group D, significantly lower basal concentrations of N-acetylaspartate (p=0.02), choline (p=0.03), creatine (p=0.002) and inositol (p=0.007) were detected compared to C. After the induction of hyperinsulinemia, concentrations of choline, creatine, GABA, inositol, lactate, NAA and composite signal glutamate + glutamine (Glx) stayed stable. The detection of glucose signal is less realiable at 1.5 Tesla but we registered the alteration in glucose concentration (p=0.003) in the whole group. Originally sightly elevated glucose concentration in D decreased on the contrary to the increase of originally lower glucose level in C. In conclusions, brain metabolism was altered in D. Short term supraphysiological euglycemic hyperinsulinemia induced changes in the concentration of brain glucose in both C and D., S. Kratochvílová, A. Škoch, M. Dezortová, E. Švehlíková, M. Hill, J. Brunová, M. Hájek, T. Pelikánová., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

457. Effect of aerobic training and resistance training on circulating irisin level and their association with change of body composition in overweight/obese adults: a pilot study

Creator:
Kim, Hee-Jae, Lee, Hyo-Joo, So, Byunghun, Son, jun Seok, Yoon, Donghyun, and Song, Wook
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Fyziologie člověka a srovnávací fyziologie, obezita, obesity, irisin, myokin, aerobic training, resistance training, 14, and 612
Language:
English
Description:
The novel myokine irisin has been reported as a therapeutic target for metabolic disease. The objective of this study is to reveal the effects of aerobic training (AT) and resistance training (RT) on circulating irisin levels and their associations with change of body composition in overweight/obese adults. Twenty eight overweight/obese adults (BMI>23 kg/m2) were included in this study and compared before and after 8 weeks of exercise program (60 min/day, 5 times in a week). The subjects, in both aerobic and resistance training, showed significant improvement in anthropometric parameters and exercise capacities including maximal oxygen uptake and muscle strength. Interestingly, the circulating irisin was significantly increased in resistance training group (p=0.002) but not in aerobic training (p=0.426) compared to control group. In addition, we found the positive correlation between change of the circulating irisin and muscle mass (r=0.432, p=0.022) and the negative correlation between change of the circulating irisin and fat mass (r=-0.407, p=0.031). In the present pilot study, we found that circulating irisin level was increased by 8 weeks of resistance training in overweight/obese adults, suggesting that resistance training could be the efficient exercise type in overweight/obese considering positive change of body composition concomitant with increase of irisin levels., Hee-Jae Kim, Hyo-Joo Lee, Byunghun So, Jun Seok Son, Donghyun Yoon, Wook Song., and Obsahuje bibliografii
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http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

458. Effect of agroclavine on NK activity in vivo under normal and stress conditions in rats

Creator:
Miroslav Starec, Anna Fišerová, Jozef Rosina, Jiří Málek, and Miloslav Kršiak
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Fyziologie člověka a srovnávací fyziologie, stres (fyziologie), toxicita, stress (physiology), toxicity, agroclavine, ergot alkaloid, rat, NK cell activity, 14, and 612
Language:
English
Description:
Agroclavine is a natural, clavine type of ergot alkaloid with D1 dopamine and ?-adrenoceptor agonistic properties. We showed previously that in vitro agroclavine enhances natural killer (NK) cell activity, increases interleukin-2 and interferon-gamma production and prolongs the survival time of tumor-bearing mice. The aim of this study was 1) to test the effect of agroclavine on NK activity in vivo, and 2) to assess the potential toxicity of high doses of agroclavine on cardiac and liver functions using creatine kinase MB (CKMB) and alanine aminotransferase (ALT) as biochemical markers in normal and stressed animals. The effect of stress was studied because we examined promising anticancer properties of agroclavine and malignant diseases are supposed to be a potent stressful event for patients. In our experiments 3-month-old male rats of the Wistar-Kyoto strain were used. Agroclavine was injected intraperitoneally (0.5 mg/kg or 0.05 mg/kg) 30 min before stress (four hours' restraint and immersion in 23 °C water). The animals were killed 30 min after stress, blood was collected and the spleen was removed. Non-stressed animals treated with agroclavine were killed 5 h after the drug administration. The results confirmed our previous in vitro results and showed that also in vivo agroclavine increases NK cell activity under non-stress conditions. Agroclavine only slightly increased CKMB and had no influence on ALT in non-stressed animals. These promising results are limited by the fact that agroclavine (0.5 mg/kg) diminished NK cell activity and significantly increased ALT and CKMB under stress conditions., M. Starec, A. Fišerová, J. Rosina, J. Málek, M. Kršiak., and Obsahuje bibliografii
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http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

459. Effect of an increase in coronary perfusion on transmural ventricular repolarization

Creator:
Zhang, Z.-Z., Bin He, and Wang, Lexin
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Patologie. Klinická medicína, kardiologie, srdeční arytmie, oxid dusnatý, cardiology, cardiac arrhythmia, nitric oxide, repolarization, activation-recovery interval, coronary flow, 14, and 616
Language:
English
Description:
The effect of increased coronary flow on transmural ventricular repolarization was investigated in six pentobabital-anesthetized sheep. Fresh blood at 10 ml/min was injected into the left circumflex coronary artery (LCX) in addition to the normal coronary flow. Unipolar electrocardiograms were simultaneously registered from epicardium, mid-myocardium and endocardium with fine plunge needles. Activation-recovery interval (ARI) was measured from the unipolar electrocardiograms and was used for estimating the ventricular repolarization duration. It was found that intracoronary blood injection (n=3) prolonged ARI in the epicardium, mid-myocardium and endocardium by an average of 34 ± 16, 28 ± 18 and 25 ± 13 ms, respectively (p<0.01). Pretreatment with nitro-L-arginine (n=3), a nitric synthase inhibitor, diminished the flow-induced ARI prolongation across the ventricular wall. In conclusion, an increase in coronary flow lengthens the duration of transmural ventricular repolarization. These effects appear to be mediated by nitric oxide from the coronary endothelium., Y.-Z. Zhang, B. He, L.-X. Wang., and Obsahuje bibliografii a bibliografické odkazy
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http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

460. Effect of an inhibitor of neuronal nitric oxide synthase 7-nitroindazole on cerebral hemodynamic response and brain excitability in urethane-anesthetized rats

Creator:
Brožíčková, C. and Jakub Otáhal
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print
Type:
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Subject:
Fyziologie člověka a srovnávací fyziologie, mozek, oxid dusnatý, brain, nitric oxide, cerebral hemodynamic response, brain excitability, neuronal nitric oxide synthase, 7-nitroindazole, rat, 14, and 612
Language:
English
Description:
The role of neuronal nitric oxide synthase (nNOS) in the pathophysiology of epilepsy and seizures remains disputable. One of the reasons why results from the acute in vivo studies display controversies might be the effect on the regulation of cerebral blood flow (CBF) during pharmacologically induced alterations of NO system. We examined neurovascular coupling in the rat sensorimotor cortex in response to transcallosal stimulation under nNOS inhibition by 7-nitroindazole (7-NI). Adult Wistar rats were anesthetized with urethane and epidural silver EEG electrodes were implanted over sensorimotor cortices. Regional CBF was measured by Laser Doppler Flowmetry (LDF). We catheterized a common carotid artery to measure arterial blood pressure (BP). 7-NI did not significantly affect blood pressure and heart rate. Electrophysiological recordings of evoked potentials (EPs) revealed no effect on their ampl itude, rhythmic potentiation or depression of EPs. Transcallosal stimulation of the contralateral cortex induced a frequency dependent rise in CBF. Although 7-NI did not significantly affect basal CBF and cortical excitability, hemodynamic responses to the transcallosal stimulation were diminished implicating a role of nNOS in neurovascular coupling. Urethane anesthesia is suitab le for future epileptological experiments. Our findings demonstrate that NO contributes to the hemodynamic response during brain activation., C. Brožíčková, J. Otáhal., and Obsahuje bibliografii a bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

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