The aim of this study was to investigate whether the inhibition of one of the endothelial receptor sites in the rat pulmonary artery (muscarinic, histaminergic, purinergic, a 2-adrenergic) affects the NO-mediated relaxation induced by the activation of the other type of receptors. Acetylcholine (ACh)-, histamine (Hist)-, adenosine (Ade)- , and clonidine (Clon)-induced endothelium-dependent relaxations were reduced by the administration of specific antagonists of muscarinic, H1-histaminergic, purinergic or a 2-adrenergic receptors, respectively. The inhibition of H1-histaminergic receptors by chlorphenyramine did not prevent ACh-induced relaxation. Similarly, the inhibition of muscarinic receptors by atropine did not prevent the relaxations to histamine, adenosine and clonidine. On the other hand, the relaxations induced by acetylcholine, histamine, adenosine or clonidine were regularly reduced by NO-synthase inhibitor NG-nitro-L-arginine methyl ester (10-4 mol/l). These results suggest that the inhibition of NO-synthase abolished arterial relaxations induced by all agonists. After inhibition of one type of the endothelial receptors, the NO-dependent relaxation could still be evoked by activation of one of the others., S. Kyselá, J. Török., and Obsahuje bibliografii
The aim of our study was to inve stigate mechanism of action of endothelins 1, 2 and 3 on spontaneous activity, tone and intraluminal pressure of human ureter. Both longitudinal tension and intraluminal pressure were recorded from the isolated segments of proximal human ureter. Endothelins 1, 2 and 3 (5.35x10 -11 M- 5.05x10-8M) produced concentration-dependent tonic contraction and sustained increase in intraluminal pressure of isolated preparations of hum an ureter. Endo thelins 1 and 3 produced also concentration-dependent inhibition of spontaneous, phasic contractions of the isolated preparations. Selective antagonist of ETA receptors BQ123 and selective antagonist of ET B receptors BQ788 produced significant inhibition of endothelin-1-induced tonic contraction (pA2=8.80 and 6.55, respectively) and increase in intraluminal pressure (pA2=8.68 and 7.02, respectively), while they did not affect endothelin-1-induced inhibition of spontaneous activity. Endothelin 1 produces increase in tone and intraluminal pressure of isolated human ureter acting on both ETA and ETB receptors, the first one being functionally more important. On ly endothelins 1 and 3 inhibit spontaneous, phasic activity of human ureter, but this effect was not blocked by selective antagonists of ETA and ETB receptors., S. M. Jankovic ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
We aimed to compare the effect of angiotensin converting enzyme (ACE) inhibitors captopril (containing thiol group) and enalapril (without thiol group) on the development of spontaneous hypertension and to analyze mechanisms of their actions, particularly effects on oxidative stress and NO production. Six-week-old SHR were divided into three groups: control, group receiving captopril (50 mg/kg/day) or enalapril (50 mg/kg/day) for 6 weeks. At the end of experiment, systolic blood pressure (SBP) increased by 41 % in controls. Both captopril and enalapril prevented blood pressure increase, however, SBP in the captopril group (121±5 mmHg) was significantly lower than that in the enalapril group (140±5 mmHg). Concentration of conjugated dienes in the aorta was significantly lower in the captopril group compared to the enalapril group. Captopril and enalapril increased NO synthase activity in the heart and aorta to the similar level. Neither captopril nor enalapril was, however, able to increase the expression of eNOS. Both ACE inhibitors increased the level of cGMP. However, cGMP level was significantly higher in the aorta of captopril group. We conclude that captopril, beside inhibition of ACE, prevented hypertension by increasing NO synthase activity and by simultaneous decrease of oxidative stress which resulted in increase of cGMP concentration., O. Pecháňová., and Obsahuje bibliografii
The present study proposed procedure for predicting an optimal left and right ventricular pacing interval delay (V-V interval). In 16 patients (heart failure, left bundle branch block, biventricular pacing) two methods (A and B) identifying optimal V-V interval were tested. Method A: predicted optimal V-V interval A (POVV-A) = electromechanical delay of the segment paced by left ventricle lead minus electromechanical delay of the segment paced by right ventricle lead. Method B: predicted optimal V-V interval B (POVV-B) = difference in the onset of aortic and pulmonary flows. Both methods were validated using echocardiography and right-sided heart catheterization. Cardiac output during POVV-A (4.6 l.min-1 ) was significantly better than that during POVV-A minus 20 ms (4.3 l.min-1, p<0.01) and POVV-A plus 20 ms (4.3 l.min-1 , p<0.01), and than that during POVV-B (4.4 l.min-1, p<0.05). LV dP/dt during POVV-A (818 mm Hg.s-1 ) exceeded that during POVV-A plus 20 ms (717 mm Hg.s-1 , p<0.05) and POVV-A minus 20 ms (681 mm Hg.s-1, p<0.05), and that during POVV-B (727 mm Hg.s-1 , p<0.01). The time difference in onsets of myocardial deformation of left ventricle segment paced by the left ventricle and right ventricle lead allows identifying the optimal V-V interval and improves left ventricle performance., M. Novák, J. Lipoldová, J. Meluzín, J. Krejčí, P. Hude, V. Feitová, L. Dušek, P. Kamarýt, J. Vítovec., and Obsahuje bibliografii a bibliografické odkazy
Functional magnetic resonance imaging (fMRI) was used to demonstrate the brain activation during transition from unconscious to conscious breathing in seven healthy human subjects. In right-handed volunteers, the activated areas were found in both hemispheres. The medial part of the precentral gyrus (area 4) was constantly activated in the left hemisphere. Additional activated areas were demonstrated in the premotor cortex and in the posterior parietal cortex. The activated cortical sites exhibited analogous distribution in the right hemisphere. In two out of the seven subjects, activated sites were also observed in the cerebellar hemispheres, and in the lentiform and caudate nuclei., V. Šmejkal, R. Druga, J. Tintěra., and Obsahuje bibliografii
The aim of this study was to find the principal parameters of surface tension of the blood and verify its possible correlation with some of the commonly assessed laboratory indicators that are affected by diseases with the expected possible changes in the surface tension of the blood. The surface tension of the blood was assessed in 150 patients. At the same time, the basic biochemical and hematological parameters were determined in these patients. The results have shown a close correlation between the surface blood tension and the activity of plasma gamma-glutamyltransferase. We assume that this relationship is based on the changes in concentration of bile acids in the blood during liver or bile duct afflictions., A. Kratochvíl, E. Hrnčíř., and Obsahuje bibliografii
Plasma carnitine levels were measured in two alternative nutrition groups - strict vegetarians (vegans) and lactoovovegetarians (vegetarians consuming limited amounts of animal products such as milk products and eggs). The results were compared to an average sample of probands on mixed nutrition (omnivores). Carnitine levels were correlated with the intake of essential amino acids, methionine and lysine (as substrates of its endogenous synthesis), since the intake of carnitine in food is negligible in the alternative nutrition groups (the highest carnitine content is in meat, lower is in milk products, while fruit, cereals and vegetables contain low or no carnitine at all). An average carnitine level in vegans was significantly reduced with hypocarnitinemia present in 52.9 % of probands. Similarly, the intake of methionine and lysine was significantly lower in this group due to the exclusive consumption of plant proteins with reduced content of these amino acids. Carnitine level in lactoovovegetarians was also significantly reduced, but the incidence of values below 30 m mol/l was lower than in vegans representing 17.8 % vs. 3.3 % in omnivores. Intake of methionine and lysine was also significantly reduced in this group, but still higher compared to vegans (73 % of protein intake covered by plant proteins). Significant positive correlation of carnitine levels with methionine and lysine intake in alternative nutrition groups indicates that a significant portion of carnitine requirement is covered by endogenous synthesis. Approximately two thirds of carnitine requirement in omnivores comes from exogenous sources. The results demonstrate the risks of alternative nutrition with respect to the intake of essential amino acids, methionine and lysine, and with respect to the intake and biosynthesis of carnitine., M. Krajčovičová-Kudláčková, R. Šimončič, A. Béderová, K. Babinská, I. Béder., and Obsahuje bibliografii
Insulin resistance associated with dyslipidemia enhances cardiovascular risk. Several atherogenic indexes have been suggested to give more precise information about the risk. The aim of our study was to estimate, which atherogenic index correlates better with parameters of insulin resistance. Furthermore, we compared the parameters of lipid metabolism and insulin resistance between smokers and non-smokers. In our cross-sectional study we enrolled 729 patients with dyslipidemia which were divided into two groups - non-smokers (586) and smokers (143). We measured lipid profile, parameters of insulin resistance (fasting glycemia, insulin, HOMA-IR, C-peptide, proinsulin) and calculated atherogenic indexes - atherogenic index of plasma (log (TAG/HDL-C), AIP), ApoB/ApoA1 index and nonHDL-C. AIP was found out to show stronger correlations with parameters of insulin resistance (p<0.001, correlation coefficients ranging between 0.457 and 0.243) than other indexes (ApoB/ApoA1 or nonHDL cholesterol). AIP correlated with parameters of insulin resistance both in smokers and nonsmokers, but after adjustment (for age, body mass index, waist circumference) persisting only in non-smokers. Smokers had a wider waist circumference and a proatherogenic lipid profile. Smoking increases the risk of developing metabolic syndrome. AIP can be used in daily praxis for predicting insulin resistance in patients with dyslipidemia, predominantly in non-smokers., L'. Cibičková, D. Karásek, K. Langová, H. Vaverková, J. Orság, J. Lukeš, D. Novotný., and Obsahuje bibliografii
a1_Focal cerebral contusion can be dynamic and expansive. It has been proved that subsequent expansive contusion is caused by brain parenchyma damage, especially BBB damage. We investigated a group of patients with traumatic brain injury. The patients (n=18) were divided in to group I (n=7) of patients submitted to neurosurgery due to expansive contusion, and group II (n=11) of patients without surgery. Serum concentrations of NSE and S-100B protein were measured by electrochemiluminescence immunoassay, interleukin-6 (IL-6) was measured by chemiluminescent sequential immunometric assay and matrix metalloproteinases (MMP-9, MMP-2) were measured by immunoassays. Cortical biopsy specimens of brain were investigated by electron microscopy in patients with trauma brain injury submitted to neurosurgery. Biochemical investigation from first day up to third day after traumatic brain injury proved increased values of IL-6 (302.2±119.9 vs. 59.6±11.9 ng/l, p<0.02) and S-100B protein (3.064±1.064 vs. 0.649±0.182 μ g/l, p<0.05) in patients with expansive lesion compared to patients without expansive contusion. Significantly higher levels of MMP-9 (150.4±28.46 vs. 74.11±13.16 ng/l, p<0.05) and of MMP-2 (814.5±126.3 vs. 523.1±25.28 ng/l, p<0.05) were found during first 3 days after admission in group I compared to group II. MMP-9 has also elevated in group II from lower values after admission (74.11±13.16 ng/l) up to high levels on the 10th day of hospitalization (225.1±49.35 ng/l )., a2_Ultrastructural investigation of endothelial cells and surrounded tissue revealed perivascular hemorrhage, increased pinocytic activity of endothelial cells, and cytotoxic edema of astroglial cells. Multivesical bodies were disclosed inside the endothelial cells. Higher levels of serum protein S-100B and IL-6 correlated with ultrastructural changes of endothelial cells, and with inflammatory response following TBI, respectively., D. Vajtr ... [et al.]., and Obsahuje seznam literatury
a1_Both divisions of the autonomic nervous system are involved in regulation of urinary bladder function. Several substances, other than noradrenaline and acetylcholine, seem to play important roles in physiology and pathophysiology of lower urinary tract. In the current study, we aimed to examine if there exist interplays between nitric oxide (NO) and autonomic transmitters and if such interactions vary in different parts of the urinary bladder in healthy and cyclophosphamide (CYP)-induced cystitic rats; when administered to the animals (100 mg/kg; i.p.), the cytotoxic CYP metabolite acrolein induces bladder inflammation. In the current study a series of in vitro functional studies were performed on detrusor muscle strip preparations. Stimulation with electrical field stimulation (EFS), methacholine, adenosine 5´-triphosphate (ATP), and adrenaline evoked contractile responses in isolated bladder preparations that were significantly reduced in cyclophosphamide (CYP)-treated rats. While the nitric oxide synthase inhibitor N ω -nitro-L-arginine (L-NNA; 10-4 M) did not affect contractile responses in normal, healthy strip preparations, it significantly increased the contractile responses to EFS, methacholine and adrenaline, but not to ATP, in the bladders from the CYP-treated rats. In the CYP-treated rats, the ATP-evoked relaxatory part of its dual response (an initial contraction followed by a relaxation) was 6-fold increased in comparison with that of normal preparations, whereas the isoprenaline relaxation was halved in the CYP-treated. While L-NNA (10-4 M) had no effect on the isoprenaline-evoked relaxations, it reduced the ATP-evoked relaxations in strip preparations from the bladder body of CYP-treated rats., a2_Stimulation of β2- and β3-adrenoceptors evoked relaxations and both responses were reduced in cystitis, the latter to a larger extent. In the trigone, the reduced ATP-evoked contractile response in the inflamed strips was increased by L-NNA, while L-NNA had no effect on the ATP-evoked relaxations, neither on the relaxations in healthy nor on the larger relaxations in the inflamed trigone. The study shows that both contractile and relaxatory functions are altered in the state of inflammation. The parasympathetic nerve-mediated contractions of the body of the bladder, evoked by the release of ATP and acetylcholine, were substantially reduced in cystitis. The relaxations to β-adrenoceptor and purinoceptor stimulation were also reduced but only the ATPevoked relaxation involved NO., R. Veselá ... [et al.]., and Obsahuje seznam literatury