Mitochondrial dysfunction and oxidative stress participate in the development of diabetic complications, however, the mechanisms of their origin are not entirely clear. Coenzyme Q has an important function in mitochondrial bioenergetics and is also a powerful antioxidant. Coenzyme Q (CoQ) regenerates alpha-tocopherol to its active form and prevents atherogenesis by protecting low-density lipoproteins against oxidation. The aim of this study was to ascertain whether the experimentally induced diabetes mellitus is associated with changes in the content of endogenous antioxidants (alpha-tocopherol, coenzymes Q9 and Q10) and in the intensity of lipoperoxidation. These biochemical parameters were investigated in the blood and in the isolated heart and liver mitochondria. Diabetes was induced in male Wistar rats by a single intravenous injection of streptozotocin (45 mg.kg-1), insulin was administered once a day for 8 weeks (6 U.kg-1). The concentrations of glucose, cholesterol, alpha-tocopherol and CoQ homologues in the blood of the diabetic rats were increased. The CoQ9/cholesterol ratio was reduced. In heart and liver mitochondria of the diabetic rats we found an increased concentration of alpha-tocopherol, however, the concentrations of CoQ9 and CoQ10 were decreased. The formation of malondialdehyde was enhanced in the plasma and heart mitochondria. The results have demonstrated that experimental diabetes is associated with increased lipoperoxidation, in spite of the increased blood concentrations of antioxidants alpha-tocopherol and CoQ. These changes may be associated with disturbances of lipid metabolism in diabetic rats. An important finding is that heart and liver mitochondria from the diabetic rats contain less CoQ9 and CoQ10 in comparison with the controls. We suppose that the deficit of coenzyme Q can participate in disturbances of mitochondrial energy metabolism of diabetic animals., J. Kucharská, Z. Braunová, O. Uličná, L. Zlatoš, A. Gvozdjáková., and Obsahuje bibliografii
a1_With hypoxic stress, hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) are elevated and their responses are altered in skeletal muscles of plateau animals [China Qinghai-Tibetan plateau pikas (Ochotona curzoniae )] as compared with control animals [normal lowland Sprague-Dawley (SD) rats]. The results indicate that HIF-1α and VEGF are engaged in physiological functions under hypoxic environment. The purpose of the current study was to examine the protein levels of VEGF receptor subtypes (VEGFRs: VEGFR-1, VEGFR-2 and VEGFR-3) in the end organs, namely skeletal muscle, heart and lung in response to hypoxic stress. ELISA and Western blot analysis were employed to determine HIF-1α and the protein expression of VEGFRs in control animals and plateau pikas. We further blocked HIF-1α signal to determine if HIF-1α regulates alternations in VEGFRs in those tissues. We hypothesized that responsiveness of VEGFRs in the major end organs of plateau animals is differential with insult of hypoxic stress and is modulated by low oxygen sensitive HIF-1α. Our results show that hypoxic stress induced by exposure of lower O2 for 6 h significantly increased the levels of VEGFR-2 in skeletal muscle, heart and lung and the increases were amplified in plateau pikas. Our results also demonstrate that hypoxic stress enhanced VEGFR-3 in lungs of plateau animals. Nonetheless, no significant alternations in VEGFR-1 were observed in those tissues with hypoxic stress. Moreover, we observed decreases of VEGFR-2 in skeletal muscle, heart and lung; and decreases of VEGFR-3 in lung following HIF-1α inhibition. Overall, our findings suggest that in plateau animals 1) responsiveness of VEGFRs is different under hypoxic environment; 2) amplified VEGFR-2 response appears in skeletal muscle, heart and lung, and enhanced VEGFR-3 response is mainly observed in lung; 3) HIF-1α plays a regulatory role in the levels of VEGFRs. Our results provide the underlying cellular and molecular mechanisms responsible for hypoxic environment in plateau animals, having an impact on research of physiological and ecological adaptive responses to acute or chronic hypoxic stress in humans who living at high attitude and who live at a normal sea level but suffer from hypoxic disorders., H.-C. Xie, J.-G. Li, J.-P. He., and Obsahuje bibliografii
Left atrial (LA) volume (LAV) is used for the selection of patients with atrial fibrillation (AF) to rhythm control strategies. Calculation of LAV from the LA diameters and areas by two-dimensional (2D) echocardiography may result in significant error. Accuracy of atrial volume assessment has never been studied in patients with long-standing persistent AF (LSPAF) and significant atrial remodeling. This study investigated correlation and agreement between 2D echocardiographic (Simpson method) and electroanatomic (CARTO, Biosense Webster) left and right atrial (RA) volumes (LAVECHO vs. LAVCARTO and RAVECHO vs. RAVCARTO) in patients undergoing catheter ablation for LSPAF. The study enrolled 173 consecutive subjects (females: 21 %, age: 59±9 years). There was only modest correlation between LAVECHO (92±31 ml) and LAVCARTO (178±37 ml) (R=0.57), and RAVECHO (71±29 ml) and RAVCARTO (173±34 ml) (R=0.42), respectively. LAVECHO and RAVECHO underestimated LAVCARTO and RAVCARTO with the absolute bias (±1.96 standard deviation) of -85 (-148; -22) ml and -102 (-169; -35) ml, respectively, and with the relative bias of -48 (-75; -21) % and -59 (-88; -30) %, respectively (all P<0.000001 for their mutual difference). Significant confounders of this difference were not identified. In patients with LSPAF, 2D echocardiography significantly underestimated both LA and RA volumes as compared with electroanatomic reference. This disagreement was independent of clinical, echocardiographic and mapping characteristics., L. Škňouřil, Š. Havránek, V. Bulková, M. Dorda, T. Paleček, J. Šimek, Z. Fingrová, A. Linhart, J. Januška, D. Wichterle, M. Fiala., and Obsahuje bibliografii
Gestational diabetes mellitus (GDM) and polycystic ovary syndrome (PCOS) are distinct pathologies with impaired insulin sensitivity as a common feature. The aim of this study was to evaluate the response of fat tissue adipokines and gastrointestinal incretins to glucose load in patients diagnosed with one of the two disorders and to compare it with healthy controls. Oral glucose tolerance test (oGTT) was performed in 77 lean young women: 22 had positive history of GDM, 19 were PCOS patients, and 36 were healthy controls. Hormones were evaluated in fasting and in 60 min intervals during the 3 h oGTT using Bio-Plex ProHuman Diabetes 10-Plex Assay for C-peptide, ghrelin, GIP, GLP1, glucagon, insulin, leptin, total PAI1, resistin, visfatin and Bio-Plex ProHuman Diabetes Adipsin and Adiponectin Assays (Bio-Rad). Despite lean body composition, both PCOS and GDM women were more insulin resistant than controls. Significant postchallenge differences between the GDM and PCOS groups were observed in secretion of adipsin, leptin, glucagon, visfatin, ghrelin, GIP, and also GLP1 with higher levels in GDM. Conversely, PCOS was associated with the highest resistin, C-peptide, and PAI1 levels. Our data suggest that decreased insulin sensitivity observed in lean women with GDM and PCOS is associated with distinct hormonal response of fat and gastrointestinal tissue to glucose load., D. Vejrazkova, O. Lischkova, M. Vankova, S. Stanicka, J. Vrbikova, P. Lukasova, J. Vcelak, G. Vacinova, B. Bendlova., and Obsahuje bibliografii
The aim of this study was to investigate aldose reductase inhibitory action of setipiprant as a potential additional mechanism contributing to its anti-inflammatory action. Aldose reductase activity was determined by spectrophotometric measuring of NADPH consumption. Setipiprant was found to inhibit aldose reductase/NADPH-mediated reduction of 4-hydroxynonenal, 4-hydroxynonenal glutathione and prostaglandin H2 substrates, all relevant to the process of inflammation. Molecular modeling simulations into the aldose reductase inhibitor binding site revealed an interaction pattern of setipiprant. Considering multifactorial etiology of inflammatory pathologies, it is suggested that, in addition to the antagonizing prostaglandin D2 receptor, inhibition of aldose reductase may contribute to the reported anti-inflammatory action of setipiprant., J. Ballekova, M. Soltesova-Prnova, M. Majekova, M. Stefek., and Obsahuje bibliografii
Renal sympathetic hyperactivity is critically involved in hypertension pathophysiology; renal denervation (RDN) presents a novel strategy for treatment of resistant hypertension cases. This study assessed effects of two RDN systems to detect acute intravascular, vascular and peri-vascular changes in the renal artery, and renal nerve alterations, in the sheep. The procedures using a single-point or multi-point ablation catheters, Symplicity FlexTM, Medtronic versus EnligHTNTM, St. Jude Medical were compared; the intact contralateral kidneys served as controls. Histopathological and immunohistochemical assessments were performed 48 h after RDN procedures; the kidney and suprarenal gland morphology was also evaluated. Special staining methods were applied for histologic analysis, to adequately score the injury of renal artery and adjacent renal nerves. These were more pronounced in the animals treated with the multi-point compared with the single-point catheter. However, neither RDN procedure led to complete renal nerve ablation. Forty-eight hours after the procedure no significant changes in plasma and renal tissue catecholamines were detected. The morphologic changes elicited by application of both RDN systems appeared to be dependent on individual anatomical variability of renal nerves in the sheep. Similar variability in humans may limit the therapeutic effectiveness of RDN procedures used in patients with resistant hypertension., M. Táborský, D. Richter, Z. Tonar, T. Kubíková, A. Herman, J. Peregrin, L. Červenková, Z. Husková, L. Kopkan., and Obsahuje bibliografii
We investigated the impact of a high-fat (HF) diet during pre- and post-weaning periods on the intestinal microbiota and alkaline phosphatase (AP) activity in male rats. Nutrition from birth was influenced by feeding rat dams with either a standard or HF diet. After weaning male pups nursed by control dams continued on a standard diet (CC) or HF diet (C-HF), while offspring nursed by HF dams continued on HF diet (HF) or standard diet (HF-C). The numbers of Bacteroides/Prevotella (BAC) and Lactobacillus/Enterococcus (LAB) in the gut were determined by FISH technique. HF pups displayed enhanced adiposity and increased AP activity (19 %), as well as higher LAB (P<0.001) and lower numbers of BAC (P<0.001) in the jejunum and colon than controls. In HF-C rats, post-weaning lower fat intake resulted in decreased fat deposition accompanied by reduced AP activity (20 %) compared to HF rats. Composition of the intestinal microbiota in these rats was not influenced. In contrast, in comparison with controls, C-HF rats displayed higher LAB (P<0.001) and lower BAC (P<0.001) together with increased adiposity and AP activity (14 %). These results indicate that consumption of diet with different fat content could modulate gut microbial/functional conditions depending on the period when the nutritional manipulation occurs., Z. Šefčíková, D. Bujňáková., and Obsahuje bibliografii
Abundant evidence indicates that ATP and adenosine act as neurotransmitters or co-transmitters, influencing nerve cell physiology in various ways. Therefore, regulation of ATP-metabolizing enzymes is essential for the normal development and function of neuronal tissue. In the present study we have examined the effect of gonadal (OVX) or adrenal (ADX) steroid hormone deprivation on the activity and expression of synaptic membrane ecto-ATPase in three extrahypothalamic brain areas of female rats, primarily not associated with reproductive function. It was shown that OVX significantly increased ecto-ATPase activity and the relative abundance of this enzyme in the hippocampal (Hip) and caudate nucleus (CN), but not in brain stem (BS) membrane preparations. ADX was followed by an upregulation of the enzyme activity and its relative abundance in all the brain areas investigated. The highest enzyme activity and the most profound effects of OVX and ADX were detected in the CN. The results obtained indicate that ADX and OVX upregulate the expression of ecto-ATPase, potentiating the production of adenosine in synaptic cleft thus modulating the activity of numerous neurotransmitter systems in distinct areas of the CNS., N. Nedeljkovic, V. Djordjevic, A. Horvat, G. Nikezic, D.T. Kanazir., and Obsahuje bibliografii
Various types of mechanosensitive ion channels, including cationic stretch-activated channels (SAC NS ) and stretch-activated BKca (SAKca) channels, modulate heart rhythm. Bepridil has been used as an antiarrhythmic drug with multiple pharmacological effects; however, whether it is effective for mechanically induced arrhythmia has not been well investigated. To test the effects of Bepridil on SAKca channels activity, cultured chick embryo nic ventricular myocytes were used for single - channel recordings. Bepridil significantly reduced the open probability of the SAKca channel (PO). Next, to test the effects of bepridil on stretch-induced extrasystoles (SIE), we used an isolated 2-week-old Langendorff-perfused chick heart. The left ventricle (LV) volume was rapidly changed, and the probability of SIE was calculated in the presence and absence of bepridil, and the effect of the drug was compared with that of Gadolinium (Gd3+). Bepridil decreased the probability of SIE despite its suppressive effects on SAKca channel activity. The effects of Gd3+, which blocks both SAKca and SACNS , on the probability of SIE were the same as those of bepridil. Our results suggest that bepridil blocks not only SAKc a channels but possibly also blocks SACNS , and thus decreases the stretch -induced cation influx (stabilizing membrane potential) to compensate and override the effects of the decrease in outward SAKca current (destabilizing membrane potential)., H. Jin, G. Iribe, K. Naruse., and Obsahuje bibliografii
Acute lung injury (ALI) is associated with det erioration of alveolar-capillary lining and transmigration and activation of inflammatory cells. Whereas a selective phosphodiesterase-4 (PDE4) inhibitor roflumilast has exerted potent anti-inflammatory properties, this study evaluated if its intravenous delivery can influence inflammation, edema formation, and respiratory parameters in rabbits with a lavage-induced model of ALI. ALI was induced by repetitive saline lung lavage (30 ml/kg). Animals were divided into 3 groups: ALI without therapy (ALI), ALI treated with roflumilast i.v. (1 mg/kg; ALI+Rofl), and healthy ventilated controls (Control), and were ventilated for following 4 h. Respiratory parameters (blood gases, ventilatory pressures, lung compliance, oxygenation indexes etc.) were measured and ca lculated regularly. At the end of experiment, animals were overdosed by anesthetics. Total and differential counts of cells in bronchoalveolar lavage fluid (BAL) were estimated microscopically. Lung edema was expressed as wet/dry lung weight ratio. Treatment with roflumilast reduced leak of cells (P<0.01), particularly of neutrophils (P<0.001), into the lung, decreased lung edema formation (P<0.01), and improved respiratory parameters. Concluding, the results indicate a future potential of PDE4 inhibitors also in the therapy of ALI., P. Kosutova, P. Mikolka, M. Kolomaznik, S. Rezakova, A. Calkovska, D. Mokra., and Obsahuje bibliografii