We tested whether seal location at iliac crest (IC) or upper abdomen (UA), before and during lower body negative pressure (LBNP), would affect thoracic electrical impedance, hepatic blood flow, and central cardiovascular responses to LBNP. After 30 min of supine rest, LBNP at -40 mmHg was applied for 15 min, either at IC or UA, in 14 healthy males. Plasma density and indocyanine green concentrations assessed plasma volume changes and hepatic perfusion. With both sealing types, LBNP-induced effects remained unchanged for mean arterial pressure (-3.0±1.1 mm Hg), cardiac output (-1.0 l min-1), and plasma volume (-11 %). Heart rate was greater during UA (80.6±3.3 bpm) than IC (76.0±2.5 bpm) (p<0.01) and thoracic impedance increased more using UA (3.2±0.2 Ω) than IC (1.8±0.2 Ω) (p<0.0001). Furthermore, during supine rest, UA was accompanied by lower thoracic impedance (26.9±1.1 vs 29.0±0.8 Ω , p<0.001) and hepatic perfusion (1.6 vs 1.8 l.min-1, p<0.05) compared to IC. The data suggest that the reduction in central blood volume in response to LBNP depends on location of the applied seal. The sealing in itself altered blood volume distribution and hepatic perfusion in supine resting humans. Finally, application of LBNP with the seal at the upper abdomen induced a markedly larger reduction in central blood volume and greater increases in heart rate than when the seal was located at the iliac crest., N. Goswami ... [et al.]., and Obsahuje seznam literatury
The aim of this study was to follow up whether the modification of pro-antioxidant status by oral thiol administration such as N- acetylcysteine and α-lipoic acid affects the hematological response. Twenty-eight healthy men participated in two independent experiments. Subjects were randomly assigned to one of four groups: controls (CNAC and CALA ), N-acetylcysteine (NAC) and α-lipoic acid (ALA). 1200 mg of N-acetylcysteine, 600 mg of α-lipoic acid or placebo were administered for 8 days in two doses. NAC or ALA administration significantly elevated plasma total antioxidant stat us (TAS) and reduced protein carbonylation (PC) and lipid peroxidation (TBARS) by more than 30 %. The reduced glutathione (GSH) and hematological parameters changed only in response to NAC administration. NAC significantly elevated the level of GSH (+33 %), EPO (+26 %), Hb (+9 %) and Hct (+9 %) compared with CNAC. The mean corpuscular volume (MCV) and the mean corpuscular hemoglobin (MCH) also increased by more than 12 % after NAC. The numerous negative or positive correlations between the measures of TAS, PC, TBARS and hematological parameters were found, which suggest the NAC-induced interaction between pro-antioxidant and hematological values. Our study has shown that both N-acetylcysteine and α-lipoic acid intake reveal an antioxidant action, but only N-acetylcysteine improves the haematological response., A. Zembron-Lacny ... [et al.]., and Obsahuje seznam literatury
Sudden death is a possible occurrence for newborns younger than 1 year with severe aortic coarctation (CoA) before surgical correction. In our previous study, we showed a significant increase of QTc-D and JTc-D in newborns with isolated severe aortic coarctation, electrocardiog raphic parameters that clinical and experimental studies have suggested could reflect the physiological variability of regional and ventricular repolarization and could provide a substrate for life-threatening ventricular arrhythmias. The aim of the current study was to evaluate the effect of surgical repair of CoA on QTc-d, JTc-d in severe aortic coarctation newborns with no associated congenital cardiac malformations. The study included 30 newborns (18M; 70±12 h old) affected by severe congenit al aortic coarct ation, without associated cardiac malformation s. All newborns underwent to classic extended end-to-end repair. Echocardiographic and electrocardiographic measurements were performed in each patient 24 h before and 24 h afte r the interventional procedure and at the end of the follow-up period, 1 month after the surgical correction. All patients at baseline, 24 h and one month after CoA surgical repair did not significantly differ in terms of heart rate, weight, height, and echocardiographic parameters. There were no statistically significant differences in QTc-D (111.7±47.4 vs 111.9±63.8 ms vs 108.5±55.4 ms; P =0.4) and JTc-D (98.1±41.3 vs 111.4±47.5 vs 105.1±33.4 ms; P =0.3) before, 24 h and 1 month after CoA surgical correction. In conclusions, our study did not show a statistically signif icant decrease in QTc-D and JTc- D, suggesting the hypothesis that the acute left ventricular afterload reduction, related to successful CoA surgical correction, may not reduce the ventricular electrical instability in the short- term follow-up., G. Nigro ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Two different isolated skeletal muscles of Japanese quail were used. The influence of branched chain amino acids on the fractional rate of protein synthesis (FSR) was evaluated using 14C-tyrosine. The addition of 0.5 mM valine, leucine or isoleucine to the incubation medium significantly decreased (P<0.05) the value of FSR in extensor metacarpalis radialis. In the ambiens muscle only the application of leucine increased the FSR significantly while valine and isoleucine were without any effect., J. Antalíková, J. Jankela, M. Baranovská., and Obsahuje bibliografii
Increased and prolonged postprandial lipemia has been identified as a risk factor of cardiovascular disease. However, there is no consensus on how to test postprandial lipemia, especia lly with respect to the composition of an experimental meal. To address this question of how glucose, when added to a fat load, affects the selected parameters of postprandial lipemia, we carried out a study in 30 healthy male volunteers. Men consumed an experimental meal containing either 75 g of fat + 25 g of glucose (F+G meal) or 75 g of fat (F meal) in a control experiment. Blood was taken before the meal and at selected time points within the following 8 h. Glucose, when added to a fat load, induced an increase of glycemia and insulinemia and, surprisingly, a 20 % reduction in the response of both total and active glucagon -like peptide -1 (GLP -1) concentration. The addition of glucose did not affect the magnitude of postprandial triglyceridemia and TRL -C and TRL -TG concentrations but stimulated a faster response of chylomicrons to the test meal, evaluated by changes in apolipoprotein B -48 concentrations. The addition of glucose induced the physiological response of insulin and the lower response of GLP -1 to the test meal during the early postprandial phase, but had no effect on changes of TRL -cholesterol and TRL -TG within 8 h after the meal., K. Zemánková, J. Mrázková, J. Piťha, J. Kovář., and Obsahuje bibliografii
Experiments were conducted to study the effect of goldthioglucose (GTG) upon the processes associated with lipid peroxidation. The glucose-6-phosphate dehydrogenase activity (G6PD; E.C.1.1.1.49) in red blood cells (RBC) and the amount of malonaldehyde precursors (MDA) per gram of brain, liver and kidney were determined. Adult mice received i.p. injections for three consecutive days of either saline (controls) or GTG dissolved in saline, in a dose of 0.10 mg.g-1 or 0.15 mg.g-1 b.w. In mice receiving higher dose of GTG the G6PD activity was significantly increased (349.38± 17.46 mU.10-9 RBC compared to 258.2± 14.46 mU.10-9 RBC in control animals). The content of MDA precursors rose significantly from 4.8± 0.81 m mol.g-1 of the liver in controls to 8.12± 1.41 m mol.g -1 and 7.88± 0.51 m mol.g-1 and from 18.71± 1.01 m mol.g-1 of the kidneys in controls to 24.25± 1.25 m mol.g-1 and 24.88± 1.7 m mol.g-1 respectively. The GTG-induced higher levels of MDA precursors and increased G6PD activity in RBC corresponds to the rise in lipid peroxidation and its participation in producing the lesions after experimental and therapeutic use of gold-containing substances seems possible., D. Košťová, E. Michnová., and Obsahuje bibliografii
The aim of this study was to an alyze the effect of indapamide and its combination with ACE inhi bitor (captopril) and antioxidant (ProvinolsTM) on both myocardial hypert rophy and fibrosis. Wistar rats were treated with L-NAME (40 mg/kg/day, L); L-NAME plus indapamide (1 mg/kg/day), or captopril (10 mg/kg/day), or ProvinolsTM (40 mg/kg/day), or combination of indapamide with captopril, and indapamide with Provinols TM for 7 weeks. Blood pressure (BP), LV hypertrophy an d fibrosis were determined. The content of collagens type I and III was evaluated morphometrically after picrosirius red staining. L-NAME treatment led to increased BP, LV hypertroph y, total fibrosis and relative content of collagens without th e change in collagen type I/III ratio. Indapamide and captopri l decreased BP, LV hypertrophy and the collagen ratio without affecting total fibrosis, while ProvinolsTM reduced BP, the collagen ratio and fibrosis without affecting LV hypertrophy. The combinations decreased all the parameters. Decrease of LV hypertrophy was achieved by drugs with the best reducing effect on BP, fibrosis reduction was reached by the antioxidant treatment with only partial effect on BP. Thus, the combination of an tihypertensive and antioxidant treatment may represent a powerful tool in preventing myocardial remodeling induced by hypertension., L. Hlavačková ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
The endocrine response is an important component of the physiological response to blood loss. There is some variability in reported levels of certain hormones during hemorrhage such as the stress hormone adrenocorticotrophic hormone (ACTH). Therefore, the effect of two an esthetic agents, ketamine and saffan, on ACTH and β-endorphin levels during hemorrhage was assessed in 12 minipigs. The animals were divided into two groups, group I saffan and group II ketamine (n=6). Pigs were subjected to a continuous fixed volume hemorrhage under one of the above anesthetics while spontaneously breathing. Blood pressure and heart rate responses were recorded together with β-endorphin and ACTH levels both before and at 10, 20, 30, 40 min after the onset of bleeding. ACTH levels were higher in the ketamine-anesthetized pigs and rose significantly faster with falling blood pressure than ACTH measured in pigs under saffan anesthesia. In contrast, the hemorrhage induced β-endorphin increase was not significantly different between the two anesthetic groups. These results indicate that choice of anesthetic agent is important when investigating the hormone response to hemorrhage and may account for the variable hormone levels in the published literature to date., T. Ruan-O´Hora, W. J. Hall, F. Markos., and Obsahuje seznam literatury
This study was designed to investigate effect of alpha-lipoic acid (LA) on lipid peroxidation, nitric oxide production and antioxidant systems in rats exposed to chronic restraint stress. Twenty four male Wistar rats, aged three months, were divided into four groups: control (C), the group treated with LA (L), the group exposed to restraint stress (S) and the group exposed to stress and treated with LA (LS). Restraint stress was applied for 21 days (1 h/day) and LA (100 mg/kg/day) was injected intraperitonally to the L and LS groups for the same period. Restraint stress significantly decreased brain copper/zinc superoxide dismutase (Cu,Zn-SOD) and brain and retina glutathione peroxidase (GSH-Px) and catalase (CAT) activities compared with the control group. Thiobarbituric acid reactive substances (TBARS), nitrite and nitrate levels were significantly increased in the tissues of the S group compared with the C group. LA produced a significant decrease in brain and retina TBARS, nitrite and nitrate levels of the L and LS groups compared to their corresponding control groups. LA increased all enzyme activities in the tissues of the LS group compared to the S group. Our study indicated that LA is an ideal antioxidant candidate for the prevention of stress-induced lipid peroxidation., D. Akpinar, P. Yargiçoğlu, N. Derin, Y. Alicigüzel, A. Ağar., and Obsahuje bibliografii a bibliografické odkazy