Hydrogen sulfide (H2S), an endogenous “gasotransmitter”, exists in the central nervous system. However, the central cardiovascular effects of endogenous H2S are not fully determined. The present study was designed to investigate the central cardiovascular effects and its possible mechanism in anesthetized rats. Intracerebrovent ricular (icv) injection of NaHS (0.17~17 μ g) produced a significant and dose-dependent decrease in blood pressure (BP) and heart rate (HR) (P<0.05) compared to control. The higher dose of NaHS (17 μ g, n=6) decreased BP and HR quickly of rats and 2 of them died of respiratory paralyse. Icv injection of the cystathionine beta-synthetase (CBS) activator s-adenosyl-L-methionine (SAM, 26 μ g) also produced a significant hypotension and bradycardia, which were similar to the results of icv injection of NaHS. Furthermore, the hypotension and bradycardia induced by icv NaHS were effectively attenuated by pretreatment with the KATP channel blocker glibenclamide but not with the CBS inhibitor hydroxylamine. The present study suggests that icv injection of NaHS produces hypotension and bradycardia, which is dependent on the KATP channel activation., W.-Q. Liu ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
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 present nuclear and cell body diameter measurements demonstrated size differences of the approximate cell space estimate occupied by the cell nucleus during the cell differentiation in lymphocytic, granulocytic and erythroid cell lineages. These lineages were used as convenient models because all differentiation steps were easily identified and accessible in diagnostic peripheral blood or bone marrow smears of blood donors (BDs), patients suffering from chronic lymphocytic leukemia (CLL), patients with chronic myeloid leukemia (CML) and refractory anemia (RA) of the myelodysplastic syndrome (MDS). The cell space occupied by the nucleus was constant and did not change during the cell differentiation in the lymphocytic cell lineages of BDs and CLL patients despite the decreased cell size. In contrary, the cell space occupied by the nucleus markedly decreased in differentiating cells of granulocytic and erythroid lineages of patients suffering from CML. In the erythroid cell lineage in patients with RA of MDS the small reduction of the cell space occupied by the nucleus during the differentiation was not significant. The measurements also indicated that in progenitor cells of all studied cell lineages nuclei occupied more than 70 % of the cell space. Thus, the nucleus-cytoplasmic morphological and functional equilibrium appeared to be characteristic for each differentiation step and each specific cell lineage., Karel Smetana, Hana Klamová, Dana Mikulenková, Jaroslav Čermák, Petra Otevřelová, Josef Karban, Marek Trněný., and Obsahuje bibliografii
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
The gene for connexin 37 (Cx37) is considered to be one of the candidate genes for cardiovascul ar disease. We evaluated the association between Cx37 (1019C>T) gene polymorphism (Pro319Ser) and ankle brachial blood pressure index (ABI) in women with type 1 (n=178) and ty pe 2 (n=111) diabetes, and in women from general population (n=862). All women were genotyped for Cx37 polymorphism. In addition to traditional cardiovascular risk factors, ABI was analyzed. In women with type 1 diabetes, ABI significantly decreased from TT to CC carriers (p for trend= 0.008). A similar trend was seen in women with type 2 diabetes (p=0.050) and in women with waist circumference above 75 th percentile (94 cm; n=208) of the general population (p=0.049). The gene for Cx37 was associated with subclinical atherosclerosis in women with type 1 and 2 diabetes and in women with advanced central obesity. The presence of C allele indicated increased risk., J. Piťha, J. A. Hubáček, P. Piťhová., and Obsahuje bibliografii
In order to assess whether intratesticular hormone content may be helpful for prediction of successful conception in men with fertility problems, five sex steroids, testosterone, dihydrotestosterone, androstenedione, estradiol and, for the first time epitestosterone, were measured in testicular tissue obtained by surgical retrieval from total 84 men. The group consisted of non-obstructive azoospermic men, aged 21-67 years who attended the centre for in vitro fertilization. Steroids after ether extraction and solvent partition were separated by high performance liquid chromatography and then measured by specific radioimmunoassays. The values varied considerably with means ± S.D. 2.43±2.47, 0.27±0.24, 0.080±0.13, 0.071± 0.089 and 0.31±0.27 for testosterone, dihydrotestosterone, androstenedione, estradiol and epitestosterone, respectively., L. Zamrazilová ... [et al.]., and Obsahuje seznam literatury
To test whether macrophages can play any role in hypoxic pulmonary vasoconstriction, we tested the in vitro response of rings from small pulmonary arteries to the activation of macrophages by FMLP, a substance stimulating predominantly membrane-bound NADPH oxidase. A small vessel myograph was used to measure the responses of rings from small pulmonary arteries (300-400 μ m) isolated from rat lungs. Rings from 5 rats were placed into both chambers of the myograph. The vessels were stabilized for 40 min and then normalized by automatic stretching to a wall tension equivalent to the intravascular pressure 30 mm Hg. At the start of each experiment, vessels were exposed to 80 mM K + to obtain maximal contractile response, which was used to normalize subsequent contractile responses. 2x10 6 viable macrophages, obtained by peritoneal lavage, were added into one chamber, then 5 μ M FMLP was administrated to both chambers and the tension measurement was started. The hydrogen peroxide concentration produced by stimulated macrophages was measured luminometrically. The concentrations of H 2 O 2 in specimens from chambers containing activated macrophages rose from 3.5±1.5 nM to 110±28 nM within 25 min of stimulation, while FMLP itself didn’t increase the H 2 O 2 concentration from the baseline value (4.5±3 nM) in samples from control chambers. After FMLP administration, the tension of the vessel rings in the presence of macrophages reached 0.23±0.07 of maximal contractile response, it did not change in controls. The additi on of ROS scavenger 4-hydroxy- TEMPO blocked the contractile response to the activation of macrophages. We conclude that the activation of macrophages stimulates the contraction of small pulmonary arteries and that this contraction is probably mediated by reactive oxygen species., M. Žaloudíková, J. Herget, M. Vízek., and Obsahuje bibliografii a bibliografické odkazy
The aim of the present study was to determine the optimal initial tension, i.e. initial stretch for rat coronary artery when using the multi-wire myograph system. We used the normalization procedure to mimic physiological conditions and to stretch the coronary arterial segments to normalized internal circumference (IC 1 ). It is determined the internal circumference when the vessel relaxed under a transmural pressure of 100 mm Hg (IC 100 ), and the IC 1 is calculated by multiplying the IC 100 by a factor k. The impact of different factor k on the initial stretch and agonist- induced tension of coronary arteries were investigated. The results showed that the maximal agonist-induced tension was achieved at the factor k value of 0.90 and the initial stretch tension was given 1.16±0.04 mN/mm. The most appropriate factor k value was 0.90-0.95 and the most appropriate initial tension was 1.16-1.52 mN/mm. Th e equilibration time of the coronary artery segments should be at least 1.0 h. In the same optimal initial tension, the agonist-induced tension increased as equilibration time lengthened., N.-N. Ping ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
The mitochondrial DNA (mtDNA) amount in cells as the basis for mitochondrial energy generating system, which produces ATP, plays an important role in the fetal development and postnatal morbidity. Isolated human cord blood leukocytes (HCBL) contribute very little to the overall metabolic turnover, but they may serve as easily available marker cells for the study of the mtDNA amount changes in cord blood during fetal development. The aim of our study was to analyze the mtDNA amount in HCBL. HCBL were isolated from cord blood samples of 107 neonates born between the 25th and 41st week of gestation. The mtDNA amount was analyzed by the real-time PCR method. The significant negative correlations were found between the relative mtDNA amount in HCBL and gestational age (r = -0.54, p<0.01) and birth weight (r = -0.43, p<0.01), respectively. The results revealed that the mtDNA content per cell decreases in HCBL with progressing fetal development. This may be explained by gradual shift of the hematopoiesis from fetal liver to bone marrow during the second half of pregnancy presumably accompanied by decreasing cell volume of HCBL as it was shown similarly in red blood cells., M. Pejznochová, M. Tesařová, T. Honzík, H. Hansíková, M. Magner, J. Zeman., and Obsahuje bibliografii a bibliografické odkazy