The present study was focused on regulatory role of nitric oxide on functional properties of the cardiac Na, K-ATPase in three various animal models of hypertension: spontaneously hypertensive male rats (SHR) with increased activity of nitric oxide synthase (NOS) by 60 % (Sh1), SHR with decreased activity of NOS by 40 % (Sh2) and rats with hypertension induced by L-NAME (40 mg/kg/day) with depressed activity of NOS by 72 % (LN). Studying the utilization of energy substrate we observed higher Na, K-ATPase activity in the whole concentration range of ATP in Sh1 and decreased activity in Sh2 and LN. Evaluation of kinetic parameters revealed an increase of Vmax value by 37 % in Sh1 and decrease by 30 % in Sh2 and 17 % in LN. The KM value remained unchanged in Sh2 and LN, but was lower by 38 % in Sh1 indicating increased affinity of the ATP binding site, as compared to controls. During the activation with Na+ we observed increased Vmax by 64 % and increased KNa by 106 % in Sh1. In Sh2 we found decreased Vmax by 40 % and increased KNa by 38 %. In LN, the enzyme showed unchanged Vmax with increased KNa by 50 %. The above data indicate a positive role of increased activity of NOS in improved utilization of ATP as well as enhanced binding of Na+ by the cardiac Na, K-ATPase., J. Vlkovičová, V. Javorková, L. Mézešová, O. Pecháňová, N. Vrbjar., and Obsahuje bibliografii a bibliografické odkazy
The aim of the present study was to quantify the effect of multisensory rehabilitation on rats’ cognition after an experimental brain trauma and to assess its possible clinical implications. The complex intermittent multisensory rehabilitation consisted of currently used major therapeutic procedures targeted at the improvement of cognitive functions; including multisensory and motor stimulation and enriched environment. We have confirmed this positive effect of early multisensory rehabilitation on the recovery of motor functions after traumatic brain injury. However, we have been able to prove a positive effect on the recovery of cognitive functions only with respect to the frequency of efficient search st rategies in a Barnes maze test, while results for search time and travelled distance were not significantly different between st udy groups. We have concluded that the positive effects of an early treatment of functional deficits are comparable with the clinical results in early neurorehabilitation in human patients after brain trauma. It might therefore be reasonable to apply these experimental results to human medical neurorehabilitation care., M. Lippert-Grüner ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Cigarette smoking is a risk factor for many diseases. It could be associated with sarcopenia. The aim of this meta-analysis was to determine whether smoking is an isolated risk factor for sarcopenia. We searched PubMed, Web of Science, EBSCO, and Science Direct for articles addressing the relationship between cigarette smoking and sarcopenia. A total of 12 studies containing information on 22,515 participants were included in this meta-analysis. Odds ratio (OR) was calculated for each study group and for all studies together. An OR was also calculated separately for each sex. We used a fixed-effect model in overall estimation and in males, because results of small studies were significantly different from the results of large studies in those cases and in females where the estimation showed only moderate heterogeneity we used a random-effect model. According to proposes of the Cochrane Handbook for Systematic Reviews. The resulting OR in the fixed-effect model was 1.12 (95 % CI 1.03-1.21), OR for each sex was in the fixed-effect model 1.20 (95 % CI 1.06-1.35) in males and in the randomeffect model 1.21 (95 % CI 0.92-1.59) in females. The results of this meta-analysis indicate that cigarette smoking as an isolated factor may contribute to the development of sarcopenia. However, the results of the individual studies were largely inconsistent due to different approaches of measuring the main variables which affected the results., M. Steffl, R. W. Bohannon, M. Petr, E. Kohlikova, I. Homerova., and Obsahuje bibliografii
Although the relationships between thyroid function and anthropometric parameters were studied in patients with thyroid disorders and in morbidly obese subjects, such data in normal healthy population are scarce. In our study, relationships between factors of body composition, fat distribution and age with hormones of the pituitary-thyroid axis were evaluated in a large, randomly selected sample of normal adult Czech population comprising of 1012 men and 1625 women. Our results exhibited weak, but significant relationships between body composition, body fat distribution and the parameters of pituitary-thyroid axis. Some of these associations were gender-specific. As shown by backward stepwise regression model, body fat distribution evaluated by centrality index (subscapular/triceps skinfold ratio) was negatively associated with free triiodothyronine (fT3) serum levels only in women, while a positive correlation of fT3 with BMI was specific for men. BMI was inversely related to free thyroxine (fT4) concentrations in women but not in men. The centrality index (CI) was positively related to TSH levels in both genders. The fT3/fT4 ratio, reflecting deiodinase activity, was inversely related to age and positively related to BMI in both genders, while the highly significant negative correlation between CI and fT3/fT4 ratio was specific for women., M. Dvořáková, M. Hill, J. Čeřovská, Z. Pobišová, R. Bílek, P. Hoskovcová, V. Zamrazil, V. Hainer., and Obsahuje bibliiografii a bibliografické odkazy
Preclinical atherosclerosis may represent a risk factor for venous thromboembolism (VTE). In longitudinal study we followed longitudinally 96 patients (32 men) with thrombophilias with (n=51) and without (n=45) history of VTE. In both groups we studied the changes of preclinical atherosclerosis at peripherally located arteries detected by ultrasound. In addition, we assessed changes in selected risk factors of atherosclerosis. During the mean follow-up of 56.0±7.62 months we did not find significant change in preclinical atherosclerosis defined as Belcaro score in either group (-3 % in the VTE group vs 0 % in non VTE group). Significant increase in body mass index (1.03±1.98 kg*m-2, resp. 1.21±1.67 kg*m-2, p<0.01) and non-significant increase in systolic blood pressure were detected in both groups. Waist circumference increased significantly only in patients without VTE (4.11±7.84 cm, p<0.05). No differences in changes of risk factors under study between both groups were detected. In summary, patients with thrombophilia and history of VTE showed no evidence of greater progression of atherosclerosis or increase in traditional risk factors of atherosclerosis than patients with thrombophilia without history of VTE. Unfavorable changes of body mass index, waist circumference and systolic blood pressure were detected in both groups during study period., O. Auzký, R. Dembovská, J. Mrázková, Š. Nováková, L. Pagáčová, J. Piťha., and Obsahuje bibliografii
Using non-cholesterol sterols investigation several authors postulated a hypothesis that in the metabolic syndrome cholesterol endogenous synthesis is increased and its absorption decreased. Our study is the first attempt to evaluate the direct relation of cholesterol metabolism to the principal pathogenetic phenomenon of the metabolic syndrome – namely to insulin resistance. We have measured insulin sensitivity by two methods – Quicki (Quantitative Sensitivity Check Index) and intravenous insulin tolerance test (Kitt) and 3 indirect markers - fasting insulin level, fasting C-peptide level and SHBG (sex hormone binding globulin). The investigation was performed in three groups of subjects with a different prevalence of insulin resistance: 72 non-diabetics with ischemic heart disease, 117 young blood donors and 63 type 2 diabetics on diet therapy only. Analyzing altogether 60 relationships – between four sterols (lathosterol, squalene, sitosterol and campesterol) and five markers of insulin resistance in three groups of subjects – we have found only six significant relations between cholesterol synthesis and absorption and insulin resistance in all groups of patients. Our results indicate that there exists a significant relationship between insulin sensitivity and indices of either increased cholesterol synthesis or decreased cholesterol absorption. Insulin resistance explains only a part of both abnormalities mentioned above., A. Šmahelová, R. Hypšler, T. Haas., and Obsahuje bibliografii a bibliografické odkazy
The aim of our study was to verify the relationship between heart rate (HR) and ventricular fibrillation threshold (VFT) during different types of ventilation in female Wistar rats from the circadian point of view. The ex-periments were performed under pentobarbital anesthesia (40 mg/kg i.p., adaptation to a light-dark cycle 12:12 h, open chest experiments) and the obtained results were averaged independently of the seasons. The VFT measure-ments were performed during normal ventilation (17 animals) and hypoventilation (10 animals). The HR was re-corded immediately before the rise of ventricular arrhy-thmias. Results are expressed as arithmetic means ± S.D. and differences are considered significant when p<0.05. The basic pe-riodic characteristics were calculated using single and population mean cosinor tests. The results from our experiments have demonstrate that 1) the VFT and HR respond identically to hypoventilation by a decrease in the light and also in the dark phases, and 2) hypoventilation changes the 24-h course of the VFT without a change in the 24-h rhythm of the HR. It is concluded that the HR and VFT behave as two independent functional systems without apparent significant circadian dependence during both types of ventilation., P. Švorc, I. Bračoková, I. Podlubný., and Obsahuje bibliografii
A high pulse pressure (PP) is a marker of increased artery stiffness and represents a well-e stablished independent predictor for cardiovascular morbidity and mortality. The objective of the research was to determine whether invasively measured central aortic PP was related to the presence and severity of coronary artery disease. In total 1075 consecutive stable male patients undergoing diagnostic coronary angiography with a preserved left ventricular function were included. Diseased coronary vessel (DCV) was defined by the presence of >50 % stenosis. Men were divided into 3 groups according to the increased value of PP. The average PP in the tertiles was 47.8±7.1 vs. 67.0±4.9 vs. 91.3±12.8 mm Hg (p<0,01). The si gnificant differences of DCV was found among tertiles (1.51±1.11 vs 1.80±1.04 vs. 1.99±0.98 DCV, p<0.01). Aortic PP together with age and hyperlipoproteinemia were found as factors with an independent relationship to DCV according to multivariate linear regression. In conclusions the increased value of aortic PP in the male population is independently connected with more severe atherosclerosis evaluated by the significant number of DCV., J. Pařenica ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
The purpose of the present study was to examine whether excessive CO2 output (V.co2excess) is dominantly attributable to hyperventilation during the period of recovery from repeated cycling sprints. A series of four 10-sec cycling sprints with 30-sec passive recovery periods was performed two times. The first series and second series of cycle sprints (SCS) were followed by 360-sec passive recovery periods (first recovery and second recovery). Increases in blood lactate (ΔLa) were 11.17±2.57 mM from rest to 5.5 min during first recovery and 2.07±1.23 mM from the start of the second SCS to 5.5 min during second recovery. CO2 output (V.co2) was significantly higher than O2 uptake (V.o2) during both recovery periods. This difference was defined as V.co2excess. V.co2excess was significantly higher during first recovery than during second recovery. V.co2excess was added from rest to the end of first recovery and from the start of the second SCS to the end of second recovery (CO2excess). ΔLa was significantly related to CO2excess (r=0.845). However, ventilation during first recovery was the same as that during second recovery. End-tidal CO2 pressure (PETco2) significantly decreased from the resting level during the recovery periods, indicating hyperventilation. PETco2 during first recovery was significantly higher than that during second recovery. It is concluded that V.co2excess is not simply determined by ventilation during recovery from repeated cycle sprints., T. Yano ... [et al.]., and Obsahuje seznam literatury
Inactive forearm muscle oxygenation has been reported to begin decreasing from the respiratory compensation point (RCP) during ramp leg cycling. From the RCP, hyperventilation occurs with a decrease in arterial CO2 pressure (PaCO2). The aim of this study was to determine which of these two factors, hyperventilation or decrease in PaCO2, is related to a decrease in inactive biceps brachii muscle oxygenation during leg cycling. Each subject (n = 7) performed a 6-min two-step leg cycling. The exercise intensity in the first step (3 min) was halfway between the ventilatory threshold and RCP (170±21 watts), while that in the second step (3 min) was halfway between the RCP and peak oxygen uptake (240±28 watts). The amount of hyperventilation and PaCO2 were calculated from gas parameters. The average cross correlation function in seven subjects between inactive muscle oxygenation and amount of hyperventilation showed a negative peak at the time shift of zero (r = -0.72, p<0.001), while that between inactive muscle oxygenation and calculated PaCO2 showed no peak near the time shift of zero. Thus, we concluded that decrease in oxygenation in inactive arm muscle is closely coupled with increase in the amount of hyperventilation., H. Ogata, T. Arimitsu, R. Matsuura, T. Yunoki, M. Horiuchi, T. Yano., and Obsahuje bibliografii a bibliografické odkazy