Smoking during pregnancy presents health risks for both the mother and her child. In this study we followed changes in the production of steroid hormones in pregnant smokers. We focused on changes in steroidogenesis in the blood of mothers in their 37th week of pregnancy and in mixed cord blood from their newborns. The study included 88 healthy women with physiological pregnancies (17 active smokers and 71 nonsmokers). We separately analyzed hormonal changes associated with smoking according to the sex of newborns. In women with male fetuses, we found higher levels of serum cortisone, dehydroepiandrosterone (DHEA), 7α-OH-DHEA, 17-OH pregnenolone, testosterone, and androstenedione in smokers at the 37th week compared to non-smokers. In women with female fetuses, we found lower serum levels of 7β-OH-DHEA and higher androstenedione in smokers at the 37th week. We found significantly higher levels of testosterone in newborn males of smokers and higher levels of 7α-OH-DHEA in female newborns of smokers. Smoking during pregnancy induces changes in the production of steroids in both the mother and her child. These changes are different for different fetal sexes, with more pronounced changes in mothers carrying male newborns as well as in the newborn males themselves., K. Adamcová, L. Kolátorová, T. Chlupáčová, M. Šimková, H. Jandíková, A. Pařízek, L. Stárka, M. Dušková., and Obsahuje bibliografii
The plexiform lesion is the hallmark of plexogenic pulmonary arteriopathy, which accompanies severe primary pulmonary hypertension. Over the years, a wide variety of hypotheses have been offered to explain the pathogenesis of these glomoid structures. Most recently, the new techniques and concepts of molecular biology have been applied to the study of the plexiform lesion and have indicated that they are composed of phenotypically abnormal endothelial cells with different pathogenic origins in primary and secondary pulmonary hypertension. The new approaches and concepts have suggested new vistas for exploration., A. P. Fishman., and Obsahuje bibliografii
The lipid molecule, lysophosphatidylinositol (LPI), is hypothesis ed to form part of a novel lipid signalling system that involves the G protein- coupled receptor GPR55 and distinct in tracellular signalling cascades in endothelial cells. This work aimed to study the possible mechanisms involved in LPI -evoked cytosolic Ca 2+ mobilization in human brain microvascular endothelial cells. Changes in intracellular Ca 2+ concentrations were meas ured using cell population Ca 2+ assay. LPI evoked biphasic elevation of intracellular calcium concentration, a rapid phase and a sustained phase. The rapid phase was attenuated by the inhibitor of PLC (U 73122), inhibitor of IP 3 receptors, 2 -APB and the de pletor of endoplasmic reticulum Ca 2+ store, thapsigargin. The sustained phase, on the other hand, was enhanced by U 73122 and abolished by the RhoA kinase inhibitor, Y -27632. In conclusion, the Ca 2+ signal evoked by LPI is characterised by a rapid phase of Ca 2+ release from the endoplasmic reticulum, and requires activation of the PLC -IP 3 signalling pathway. The sustained phase mainly depends on RhoA kinase activation. LPI acts as novel lipid signalling molecule in endothelial cells, and elevation of cytosolic Ca 2+ triggered by it may present an important intracellular message required in gene expression and controlling of vascular tone., Y. M. Al Suleimani, C. R. Hiley., and Obsahuje bibliografii
In this review we present immunohistochemical methods for visualization of capillaries and muscle fibres in thick muscle sections. Special attention is paid to the procedures that preserve good morphology. Applying confocal microscopy and virtual 3D stereological grids, or tracing of capillaries in virtual reality, length of capillaries within a muscle volume or length of capillaries adjacent to a muscle fibre per fibre length, fibre surface area or fibre volume can be evaluated by an unbiased approach. Moreover, 3D models of capillaries and muscle fibres can be produced. Comparison of the developed methods with counting capillary profiles from 2D sections is discussed and the reader is warned that counting capillary profiles from 2D sections can underestimate the capillary length by as much as 75 percent. Application of the described 3D methodology is illustrated by the anatomical remodelling of capillarity during acute denervation and early reinnervation in the ra t soleus and extensor digitorum longus muscles., I. Eržen, J. Janáček, L. Kubínová., and Obsahuje bibliografii a bibliografické odkazy
Nitric oxide (NO) plays a crucial role not only in regulation of blood pressure but also in maintenance of cardiac autonomic tone and its deficiency induced hypertension is accompanied by cardiac autonomic dysfunction. However, underlying mechanisms are not clearly defined. We hypothesized that sympathetic activation mediates hemodynamic and cardiac autonomic changes consequent to deficient NO synthesis. We used chemical sympathectomy by 6-hydroxydopamine to examine the influence of sympathetic innervation on baroreflex sensitivity (BRS) and heart rate variability (HRV) of chronic NG-nitro-L-arginine methyl ester (L-NAME) treated adult Wistar rats. BRS was determined from heart rate responses to changes in systolic arterial pressure achieved by intravenous administration of phenylephrine and sodium nitroprusside. Time and frequency domain measures of HRV were calculated from 5-min electrocardiogram recordings. Chronic L-NAME administration (50 mg/kg per day for 7 days orally through gavage) in control rats produced significant elevation of blood pressure, tachycardia, attenuation of BRS for bradycardia and tachycardia reflex and fall in time as well as frequency domain parameters of HRV. Sympathectomy completely abolished the pressor as well as tachycardic effect of chronic L-NAME. In addition, BRS and HRV improved after removal of sympathetic influence in chronic L-NAME treated rats. These results support the concept that an exaggerated sympathetic activity is the principal mechanism of chronic L-NAME hypertension and associated autonomic dysfunction., M. Chaswal, S. Das, J. Prasad, A. Katyal, M. Fahim., and Obsahuje bibliografii
The resting membrane potential (Vm) of isolated somatic longitudinal muscles of the earthworm Lumbricus terrestris was studied by glass microelectrodes. The inhibition of chloride permeability by low pH did not affect Vm of the muscle fibers in isolated somatic longitudinal muscles of the earthworm Lumbricus terrestris which was -48.7 mV (inside negative) at pH 7.3 and -49.1 at pH 5.6. On the other hand, bathing the muscles in Cl- and Na+-free solutions, or application of the chloride transporter inhibitor furosemide and Na+-K+-ATPase inhibitor ouabain depolarized the Vm by 3-5 mV. The effects of a Cl- -free solution and ouabain were not additive. This demonstrates relatively small contribution of equilibrium potential for Cl- to the resting membrane potential and electrogenic effect of Na+K+-ATPase which is dependent on the supply of Na+i ions by furosemide-sensitive and Cl-e- and Na+e-dependent electroneutral transport (most probably Na+K+Cl- cotransport)., E. M. Volkov, L. F. Nurullin, E. Nikolsky, J. Krůšek, F. Vyskočil., and Obsahuje bibliografii
The basis for most acute coronary events is either rupture or fissuring of unstable atherosclerotic plaques with subsequent thrombosis leading to coronary artery occlusion. The development of atherosclerotic plaques takes several decades, but the mechanical features determining its stability and the risk of rupture can change very rapidly depending on a number of internal factors. Unstable plaques have a large lipid core, a thin overlying fibrous cap and an abundance of inflammatory cells. The most important factor determining the plaque stability is the plasma level of atherogenic LDL particles. Increased levels of these particles cause endothelial dysfunction with impaired vasodilatation capacity and prevalence of vasoconstriction, maintain inflammatory infiltration of the plaque, impair the strength of the fibrous cap and facilitate aggregation and coagulation. Effective lowering of plasma cholesterol by pharmacological and non-pharmacological means can revert most of these processes and increase the plaque's mechanical stability within several hours to days. Lipid lowering therapy can therefore decrease the risk of acute coronary events within a very short space of time. Thus a radical decrease in lipid levels, along with modification of other risk factors, may become the cornerstone for treatment of acute coronary syndromes, in addition to being an effective treatment in primary and secondary prevention of coronary heart disease (CHD)., T. Štulc, R. Češka., and Obsahuje bibliografii
The aim of the present study was to investigate whether enzyme chondroitinase ABC (ChABC) treatment influences the phenotype of neural progenitor cells (NPCs) derived from injured rat spinal cord. Adult as well as fetal spinal cords contain a pool of endogenous neural progenitors cells, which play a key role in the neuroregenerative processes follow ing spinal cord injury (SCI) and hold particular promise for therapeutic approaches in CNS injury or neurodegenerative diso rders. In our study we used in vitro model to demonstrate the differentiation potential of NPCs isolated from adult rat spinal cord after SCI, treated with ChABC. The intrathecal delivery of ChABC (10 U/ml) was performed at day 1 and 2 after SCI. The present findings indicate that the impact of SCI resulted in a decrease of all NPCs phenotypes and the ChABC treatment, on the contra ry, caused an opposite effect., L. Slovinská, I. Novotná, D. Čížková., and Obsahuje bibliografii a bibliografické odkazy
The function of chromogranin A (CGA) is reviewed, and the radioimmunometric determination of plasma CGA was evaluated as a marker of pheochromocytoma using a comparison of pheochromocytoma patients immediately before surgery (group P, n=25, 635±451 ng/ml) with other groups of patients, i.e. pheochromocytoma patients approximately 1 year after removal of tumor (group PP, n=13, 69±33 ng/ml), medullary thyroid carcinoma patients (group M, n=22, 106±59 ng/ml), congenital adrenal hyperplasy patients (n=33, 65±40 ng/ml), and controls (n=31, 66±29 ng/ml). A CGA level above cut off value 130 ng/ml was found in 24 of 25 patients in group P, 1 (relapse) of 13 patients in group PP, and 4 of 22 patients in group M. In the group P we found a significant association between the size of the tumors removed and plasma CGA concentrations (p=0.0016), and also a significant (p=0.0016) relationship between plasma CGA concentrations and PASS score rating the malignity of pheochromocytoma. We can conclude that plasma CGA concentration as determined by radioimmunometric assay (which is simple without the necessity of special laboratory equipment) is an effective marker of pheochromocytoma with association to malignity and tumor mass., R. Bílek, L. Šafařík, V. Ciprová, P. Vlček, L. Lisá., and Obsahuje bibliografii a bibliografické odkazy
Acute dilation brought about by the dietary flavonoid quercetin in coronary arterioles has been described earlier, but no information is available on its chronic effects. Male Wistar rats (body weight about 190 g) were divided to two groups: the quercetin-treated group (n=22) had quercetin supplementation of approximately 30 mg/kg/day, whereas the control group (n=20) had none. After eight weeks of treatment, intramural coronary arterioles with identical passive diameters (178±14 μm and 171±9 μm) were prepared and their biomechanics and pharmacological reactivities were tested using pressure arteriography ex vivo. The spontaneous tone of quercetin-treated arteries was higher (16.5±1.9 % vs. 12.9±0.9 %), which resulted in a reduced lumen size (144±9 μm vs. 167±12 μm), thicker vascular wall (22.6±1.8 μm vs. 17.4±1.6 μm) and decreased tangential wall stress (16.8±1.1 kPa vs. 20.5±1.6 kPa) in supplemented animals (in spontaneous tone at 50 mm Hg, p<0.01 in all these comparisons). Elevated basal NO release resulted in increased endothelial dilation in quercetin-treated animals, especially at higher intraluminal pressures (10.8±2.5 % vs. 5.7±1.3 % at 70 mm Hg, p<0.01). We found remodeling of the geometry of coronary arterioles to ensure higher dilatory reserve and nitrogen monoxide production, as well as lowered elastic stress of the vessel wall., A. Monori-Kiss, F. Kiss, J. M. Restifo, E. Monos, G. L. Nadasy., and Obsahuje bibliografii