Endothelial dysfunction may be considered as the interstage between risk factors and cardiovascular pathology. An imbalance between the production of vasorelaxing and vasoconstricting factors plays a decisive role in the development of hypertension, atherosclerosis and target organ damage. Except vasorelaxing and antiproliferative properties per se, nitric oxide participates in antagonizing vasoconstrictive and growth promoting effects of angiotensin II, endothelins and reactive oxygen species. Angiotensin II is a potent activator of NAD(P)H oxidase contributing to the production of reactive oxygen species. Numerous signaling pathways activated in response to angiotensin II and endothelin-1 are mediated through the increased level of oxidative stress, which seems to be in casual relation to a number of cardiovascular disturbances including hypertension. With respect to the oxidative stress, the NO molecule seems to be of ambivalent nature. On the one hand, NO is able to reduce generation of reactive oxygen species by inhibiting association of NAD(P)H oxidase subunits. On the other hand, when excessively produced, NO reacts with superoxides resulting in the formation of peroxynitrite, which is a free radical deteriorating endothelial function. The balance between vasorelaxing and vasoconstricting substances appears to be the principal issue for the physiological functioning of the vascular bed., O. Pecháňová, F. Šimko., and Obsahuje bibliografii
Transient receptor potential vanilloid 1 (TRPV1) receptor is a nonselective cation channel activated by capsaicin, a pungent substance from chili peppers. It is considered to act as an integrator of various physical and chemical nociceptive stimuli, as it can be gated by noxious heat (>43ºC), low pH (protons) and also by recently described endogenous lipids. The structure and function of TRPV1 receptors was vigorously studied, especially since its cloning in 1997. However, most of the research was pointed towards the role of TRPV1 receptors in the peripheral tissues. Mounting evidence now suggests that TRPV1 receptors on the central branches of dorsal root ganglion neurons in the spinal cord may play an important role in modulation of pain and nociceptive transmission. The aim of this short review was to summarize the knowledge about TRPV1 receptors in the spinal cord dorsal horn, preferentially from morphological and electrophysiological studies on spinal cord slices and from in vivo experiments., D. Špicarová, J. Paleček., and Obsahuje bibliografii a bibliografické odkazy
The tissue factor (TF) is one of the most important regulators of arterial thrombosis. Because arterial thrombosis is the pathophysiologic background of acute coronary syndrome, the possible impact of blocking the arterial thrombosis on its onset is a challenging problem. The investigations of TF brought a new concept of “cell-based coagulation model” which highlighted the question of blood-borne TF as a source of TF in circulating blood. In this review we summarize essential information on the pathophysiology, molecular structure, expression and distribution of TF and we propose a novel concept of blood-borne TF, suggesting the possibilities of inhibition of the coagulation cascade with newly synthetized drugs., M. A. Malý, P. Tomašov, P. Hájek, P. Blaško, I. Hrachovinová, P. Salaj, J. Veselka., and Obsahuje bibliografii a bibliografické odkazy
The aim of this study was to explore changes in plasma vascular endothelial growth factor (VEGF) in aged patients who undergone transcatheter aortic valve implantation or balloon angioplasty for the treatment of aortic stenosis. Plasma VEGF was measured in subjects with diabetes mellitus type 2 (DM) (n=21, age 79.2±1.6 years) and in non-diabetic subjects (non-DM) (n=23, age 84.4±0.7 years), using an ELISA kit. Before the procedure plasma levels of VEGF were significantly lower in DM than in non-DM patients (P<0.05). Plasma VEGF significantly increased in both groups (DM and non-DM) 24 h (387±64 vs. 440±30 pg/ml, P<0.05) and 72 h (323±69 vs. 489±47 pg/ml, P<0.05) after the endovascular procedure. However, the VEGF in DM patients was significantly lower compared to non-DM subjects up to one month after the endovascular procedure (283±47 vs. 386±38 pg/ml, P<0.05). We conclude that increased plasma VEGF in aged patients associates with atherosclerotic aortic valve stenosis. In spite of that plasma VEGF in DM was constantly significantly lower than in non diabetic patients, both before and after the endovascular procedure, possibly reflecting a disturbance of angiogenic/antiangiogenic balance in diabetes., V. Bláha, J. Šťásek, J. Bis, J. Fortunato, C. Andrýs, V. Pavlík, P. Polanský, M. Brtko, L. Sobotka., and Obsahuje bibliografii
The skin matrix metalloproteinase 3, tissue inhibitors of matrix metalloproteinase 2 and collagen III content changes in type 1 diabetes and insulin resistance treated with insulin a nd metformin were studied. Healthy adult male Wistar rats were obtained from experimental animal house, Department of Experimental Pharmacology, Medical University in Bialystok. The rats were divided randomly into five groups of 8 rats each. Control rats were injected intraperitoneally by NaCl. Type IDDM was induced by a single injection of Streptozocin. Insulin resistance was induced by a high -fat diet. The chosen groups of rats were also treated with insulin or metformin. ELISA K its (USCN Life Science, China) were used to measure content of matrix metallo - proteinase 3 (ELISA Kit for Matrix Metalloproteinase 3 - MMP3), tissue inhibitor of matrix metalloproteinase 2 (ELISA Kit for Tissue Inhibitors of Metalloproteinase 2 - TIMP2) and content of collagen type 3 (ELISA Kit for Collagen Type III - COL3). The results were reported as a median. The statistical significance was defined as p<0.05. Type 1 diabetes and insulin resistance have significantly reduced the quality of the skin, shown by the increase in cont ent of matrix metalloproteinase 3 and the decrease in content of tissue inhibitors of matrix metalloproteinase 2. Type 1 diabetes and insulin resistance have reduced the quality of the skin expressed by type III collagen content decrease but for future studies it is recommend to determine rat interstitial collagenase, MMP -13, as well. Insulin and metformin treatment improved the quality of the diabetic skin, demonstrated by the type III collagen content increase., M. Knaś, K. Wołosik, A. Zalewska, A. Mikucka-Niczyporuk, I. Kasacka, M. Niczyporuk., and Obsahuje bibliografii
The transformed C6 glial cells in cultures were treated with sodium mercaptoborate (Na2B12H11SH, BSH), a carrier of atomic targets (10B) of thermal neutrons for the neutron capture therapy of brain tumors. As shown by light microscopy, the therapeutic dose of BSH (100 µg/ml) did not alter the gross morphology and growth of the population of cells within a 72 h treatment interval. Electron microscopic analysis of these cells revealed activation of nucleoli and, occasionally, enlarged and bifurcated mitochondria. After 200 µg BSH/ml and 72 h treatment, growth of the cell population was inhibited and ultrastructural changes became more profound. They included condensation of chromatin and its allocation to the nuclear envelope which formed deeper invaginations. Mitochondria further increased in size and were characterized by slim or angular cristae. Moreover, in circumscribed segments of some of the slightly swollen mitochondria their cristae disappeared or were reduced to fine pouch-like structures localized near the continuous outer membrane, suggestive for a non-destructive restructuring of the inner mitochondrial membrane. The smooth pinocytotic vesicles near the plasma membrane, lysosomes and heterogeneous dense bodies were more frequent. The revealed subcellular targets of BSH may initiate the development of pharmacological protocols aimed to further improve the tolerance to BSH by the healthy tissues of patients undergoing BNCT of brain tumors, e.g. by intervention into the oxidative stress triggered likely by the altered mitochondria., V. Mareš, D. Krajčí, V. Lisá., and Obsahuje bibliografii
Prolonged agonist stimulation results in specific transfer of activated Gα subunits of Gqα/G11α family from particulate membrane fraction to soluble (cytosol) cell fraction isolated as 250 000 x g supernatant. In this study, we have used 2D electrophoresis for more defined resolution of Gα subunits of Gqα/G11α family and followed the time course of solubilization effect. The small signal of soluble G proteins was already detected in control, hormone-unexposed cells. Hormone stimulation resulted in a slow but continuous increase of both intensity and number of immunoreactive signals/spots of these G proteins (10, 30, 60, 120 and 240 min). At longer times of agonist exposure (>2 hours), a marked increase of Gqα/G11α proteins was detected. The maximal level of soluble Gqα/G11α proteins was reached after 16 hours of continuous agonist exposure. At this time interval, eight individual immunoreactive signals of Gqα/G1 α proteins could be resolved. The relative proportion among these spots was 15:42:10:11:7:7:2:5. Solubilization of this class of Gα proteins was thus observed after prolonged agonist stimulation only, induced by ultra high concentration of hormone and in cells expressing a large number of GPCRs. Our data therefore rather indicate tight/persisting binding of Gqα/G11α proteins to the membrane., D. Durchánková, J. Novotný, P. Svoboda., and Obsahuje bibliografii a bibliografické odkazy
The aim of this study was to obtain a detailed analysis of the relationship between the finger arterial compliance C [ml/mm Hg] and the arterial transmural pressure Pt [mm Hg]. We constructed a dynamic plethysmograph enabling us to set up a constant pressure Pcss [mm Hg] and a superimposed fast pressure vibration in the finger cuff (equipped with a source of infra-red light and a photoelectric sensor for the measurement of arterial volume). Pcss could be set on the required time interval in steps ranging between 30 and 170 mm Hg, and on sinusoidal pressure oscillation with an amplitude Pca (2 mm Hg) and a frequency f (20, 25, 30, 35, 40 Hz). At the same time continuous blood pressure BP was measured on the adjacent finger (Portapres). We described the volume dependence of a unitary arterial length on the time-varying transmural pressure acting on the arterial wall (externally Pcss+Pca.sin(2πf), internally BP) by a second-order differential equation for volume. This equation was linearized within a small range of selected BP. In the next step, a Fourier transform was applied to obtain the frequency characteristic in analytic form of a complex linear combination of frequency functions. While series of oscillations [Pca, f] were applied for each Pcss, the corresponding response of the plethysmogram was measured. Amplitude spectra were obtained to estimate coefficients of the frequency characteristic by regression analysis. We determined the absolute value: elastance E, and its inverse value: compliance (C=1/E). Then, C=C(Pt) was acquired by applying sequences of oscillations for different Pcss (and thus Pt) by the above-described procedure. This methodology will be used for the study of finger arterial compliance in different physiological and pathological conditions., J. Moudr, J. Svačinová, E. Závodná, N. Honzíková., and Obsahuje bibliografii
To propose a test to evaluate endothelial function, based on VO 2 on-transition kinetics in sub -anaerobic threshold (AT) constant load exercise, we tested healthy subjects and patients with ischemic -hypertensive cardiopathy by two cardiopulmonary te sts on a cycle ergometer endowed with an electric motor to overcome initial inertia: a pre-test and, after at least 24 h, one 6 min constant load exercise at 90 % AT. We measured net phase 3 VO2-on kinetics and, by phase 2 time constant (τ), valued endothe lial dysfunction. We found shorter τ in repeated tests, shorter time between first and second test, by persisting endothelium -dependent arteriolar vasodilatation and/or several other mechanisms. Reducing load to 80 % and 90 % AT did not produce significant changes in τ of healthy volunteers, while in heart patients an AT load of 70 %, compared to 80 % AT, shortened τ(∆=4.38±1.65s, p=0.013). In heart patients, no correlation was found between NYHA class, ejection fraction (EF), and the two variables derived from incremental cycle cardio - pulmonary exercise, as well as between EF and τ; while NYHA class groups were well correlated w ith τ duration (r=0.92, p=0.0001). Doxazosin and tadalafil also significantly reduced τ. In conclusion, the O2 consumption kinetics during the on transition of constant load exercise below the anaerobic threshold are highly sensitive to endothelial functi on in muscular microcirculation, and constitute a marker for the evaluation of endothelial dysfunction. and D. Maione, A. F. G. Cicero, S. Bacchelli, E. R. Cosentino, D. Degli Esposti, D. N. Manners, E. R. Rinaldi, M. Rosticci, R. Senaldi, E. Ambrosioni, C. Borghi.
The aim of our study was to explore the effects of regular aerobic exercise on anthropome tric, biochemical and hormonal parameters and mRNA expression of selected factors involved in metabolic regulations in subcutaneous adipose tissue of patients with obesity. Fifteen obese wome n with arterial hypertension underwent a three-month exercise program consisting of 30 min of aerobic exercise 3 times a we ek. Fifteen healthy lean women with no intervention served as a control group. Obese group underwent anthropometric measurements, blood sampling, subcutaneous adipose tissue (SCAT) biopsy and 24-h blood pressure monitoring at baseline and after three months of exercise, while control group was examined only once. At baseline, obese group had increased SCAT expression of proinflammatory cytokines and adipokines relative to control group. Three months of regular exercise improved anthropometric parameters, decreased CRP, blood glucose and HOMA-IR, while having no significant effect on lipid profile and blood pressure. Gene expressions in SCAT were not affected by physical activity with the exce ption of increased aquaporin-3 mRNA expression. We conclude that three months of regular exercise decrease systemic subc linical inflammation with only minor influence on the blood pressure and the endocrine function of subcutaneous fat., P. Trachta, J. Drápalová, P. Kaválková, V. Toušková, A. Cinkajzlová, Z. Lacinová, M. Matoulek, T. Zelinka, J. Widimský Jr., M. Mráz, M. Haluzík., and Obsahuje bibliografii