The aim of this study was to measure expression levels of microRNAs (miRNAs) (miRNA-1, -15b and -21) in the rat myocardium after a single dose of ionizing radiation (6-7 Gy/min, total 25 Gy). The rats were treated with selected drugs (Atorvastatin, acetylsalicylic acid (ASA), Tadalafil, Enbrel) for six weeks after irradiation. MiRNAs levels were measured by RT-qPCR. Irradiation down-regulated miRNA-1 in irradiated hearts. In Tadalafil- and Atorvastatin-treated groups, miRNA-1 expression levels were further decreased compared with irradiated controls. However, Enbrel increased miRNA-1 level in irradiated hearts similarly to that in non-irradiated untreated group. Increase of miRNA-15b is pro-apoptotic in relationship with ischemia. Irradiation caused down-regulation of miRNA-15b. Administration of ASA in the irradiated group resulted in the increase of miRNA-15b expression compared to non-treated controls without irradiation. After Enbrel administration, miRNA-15b levels were overexpressed compared to non-treated normal group. MiRNA-21 belongs to the most markedly up-regulated miRNAs in response to cardiogenic stress. MiRNA-21 was increased nearly 2-fold compared to non-treated hearts whereas Tadalafil reduced miRNA-21 levels (about 40 %). Our study suggests that Enbrel and Tadalafil changed miRNAs expression values of the irradiated rats to the values of nonirradiated controls, thus they might be helpful in mitigation of radiation-induced toxicity., B. Kura, C. Yin, K. Frimmel, J. Krizak, L. Okruhlicova, R. C. Kukreja, J. Slezak., and Obsahuje bibliografii
The aim of this study was to co mpare the levels of the plasma muscle-derived cytokines (myokines) and reactive oxygen and nitrogen species (RONS) after muscle damage triggered by different exercises, and to demonstrate the relationships between RONS, thiol redox status and myokines. Sixteen young men participated in a 90-min run at 65 % VO 2 max (Ex.1) or 90-min run at 65 % VO 2 max finished with a 15-min eccentric phase (Ex.2, downhill running). Plasma samples were collected before and at 20 min, 24 h and 48 h after exercise. The exercise trials significantly elevated the concen trations of plasma hydrogen peroxide (H2O2) and 8-isoprostane at 20 min rest. Myokines IL-6 and IL-10 increased at 20 min rest while IL-1 β and TNF α increased at 24 h rest following both running. Ex.2 caused a significant increase in nitric oxide (NO), IL-6, IL-10 and oxidized glutathione (GSSG) levels. Thiol redox status (GSHtotal-2GSSG/GSSG) decreased by about 30 % after Ex.2 as compared to Ex.1. H 2 O 2 and NO directly correlated with IL-6, IL-10, IL-1 β , TNF α and glutathione. These results show that eccentric work is an important factor that enhances the production of RONS and muscle-derived cytokines, and that there is a possible participation of thiol redox status in the release of myokines to blood., A. Zembron-Lacny, M. Naczk, M. Gajewski, J. Ostapiuk-Karolczuk, H. Dziewiecka, A. Kasperska, K. Szyszka., and Obsahuje bibliografii
Parvalbumin (PV) is a calcium-binding protein that is expressed by numerous neuronal subpopulations in the central nervous system. Staining for PV was often used in neuroanatomical studies in the past. Recently, several studies have suggested that PV acts in neurons as a mobile endogenous calcium buffer that affects temporo-spatial characteristics of ca lcium transients and is involved in modulation of synaptic transmission. In our experiments, expression of PV in the lumbar dorsal horn spinal cord was evaluated using densitometric analysis of immunohistological sections and Western-blot techniques in control and arthritic rats. There wa s a significant reduction of PV immunoreactivity in the superficial dorsal horn region ipsilateral to the arthritis after induction of the peripheral inflammation. The ipsilateral area and intensity of PV staining in this area were reduced to 38 % and 37 %, respectively, out of the total PV staining on both sides. It is suggested that this reduction may reflect decreased expression of PV in GABAergic inhibitory neurons. Reduction of PV concentration in the presynaptic GABAergic terminals could lead to potentiation of inhibitory transmission in the spinal cord. Our results suggest that changes in expression of calcium-binding proteins in spinal cord dorsal horn neurons may modulate nociceptive transmission., G. Zachařová, D. Sojka, J. Paleček., and Obsahuje bibliografii
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