Peptides ghrelin, obestatin and neuropeptide Y (NPY) play an important role in regulation of energy homeostasis, the imbalance of which is associated with eating disorders anorexia (AN) and bulimia nervosa (BN). The changes in ghrelin, obestatin and NPY plasma levels were investigated in AN and BN patients after administration of a high-carbohydrate breakfast (1604 kJ). Eight AN women (aged 25.4±1.9; BMI: 15.8±0.5), thirteen BN women (aged 22.0±1.05; BMI: 20.1±0.41) and eleven healthy women (aged 25.1±1.16; BMI: 20. 9±0.40) were recruited for the study. We demonstrated increased fasting ghrelin in AN, but not in BN patients, while fasting obestatin and NPY were increased in both AN and BN patients compared to the controls. Administration of high-carbohydrate breakfast induced a similar relative decrease in ghrelin and obestatin plasma levels in all groups, while NPY remained increa sed in postprandial period in both patient groups. Ghrelin/obestatin ratio was lower in AN and BN compared to the controls. In conclusions, increased plasma levels of fasting NPY and its unchanged levels after breakfast indicate that NPY is an important marker of eating disorders AN and BN. Different fasting ghrelin and obestatin levels in AN and BN could demonstrate their diverse functions in appetite and eating suppression., D. Sedláčková ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
The aim of this study was to assess the molecular basis of renal Na,K-ATPase disturbances in response to NO-deficient hypertension induced in rats by NO-synthase inhibition with 40 mg/kg/day NG-nitro-L-arginine methyl ester (L-NAME) for four weeks. After 4-week administration of L-NAME, the systolic blood pressure (SBP) increased by 30 %. Three weeks after terminating the treatment, SBP recovered to control value. When activating the Na,K-ATPase with its substrate ATP, a 36 % increase in Km and 29 % decrease in Vmax values were observed in NO-deficient rats. During activation with Na+, the Vmax was decreased by 20 % and the KNa was increased by 111 %, indicating a profound decrease in the affinity of the Na+-binding site in NO-deficient rats. After spontaneous recovery from hypertension, the Vmax remained at the level as in hypertension for both types of enzyme activation. However, in the presence of lower concentrations of substrate which are of physiological relevance an improvement of the enzyme activity was observed as documented by return of Km for ATP to control value. The KNa value for Na+ was decreased by 27 % as compared to hypertension, but still exceeded the corresponding value in the control group by 55 % thus resulting in a partial restoration of Na+ affinity of Na,K-ATPase which was depressed as a consequence of NO-dependent hypertension., N. Vrbjar, V. Javorková, O. Pecháňová., and Obsahuje bibliografii
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