Search results for "OXIDASE"
showing 10 items of 927 documents
Poly-ADP ribose polymerase, xanthine oxidase and nitric oxide synthase expression in kidney tissue of experimental diabetes
2014
Background The spatial distribution of inflammatory and DNA reparation markers in the kidney tissue in diabetes is poorly understood. Aim The present study investigated the role of endothelial and inducible nitric oxide synthase (eNOS and iNOS), Poly ADP ribose polymerase (PARP) xanthine oxidase (XO) in the pathogenesis of streptozotocin-induced diabetic changes in the kidney tissue. Methods Diabetes mellitus was induced in rats by a single injection of streptozotocin (STZ) at a dose of 50 mg/kg. The XO, PARP, eNOS and iNOS protein expression in the kidney was studied by immunohistochemistry. Results Obtained results showed that STZ administration incresed the numbers of PARP and XO-positiv…
Lysine triggers apoptosis through a NADPH oxidase-dependent mechanism in human renal tubular cells
2012
Progressive chronic kidney disease (CKD) is common in lysinuric protein intolerance (LPI), a primary inherited aminoaciduria characterized by massive Lysine excretion in urine. However, by which mechanisms Lysine may cause kidney damage to tubule cells is still not understood. This study determined whether Lysine overloading of human proximal tubular cells (HK-2) in culture enhances apoptotic cell loss and its associated mechanisms. Overloading HK-2 with Lysine levels reproducing those observed in urine of patients affected by LPI (10 mM) increased apoptosis (+30%; p < 0.01 vs.C), as well as Bax and Apaf-1 expressions (+30-50% p < 0.05), while downregulated Bcl-2 (-40% p < 0.05). Apoptosis …
Neuronal and extraneuronal uptake and efflux of catecholamines in the isolated rabbit heart
1974
1. Isolated rabbit hearts were perfused with (−)-noradrenaline, (−)-adrenaline and (±)-isoprenaline for various time periods (1–180 min) and then washed with an amine-free medium. The venous concentration of the amine was estimated fluorimetrically during the infusion and after its end, to study removal and efflux, respectively. 2. In untreated hearts and after pretreatment with reserpine the removal had a constant rate over 20–60 min. After pretreatment with pargyline to block monoamine oxidase (MAO), however, the removal of noradrenaline declined exponentially to zero. Inhibition of the neuronal uptake (desipramine) and chemical sympathectomy (6-hydroxydopamine) abolished the removal of n…
The neuronal efflux of noradrenaline: Dependency on sodium and facilitation by ouabain
1974
Rabbit hearts were isolated after pretreatment with the MAO inhibitor pargyline and with reserpine and were perfused with 200 ng/ml noradrenaline for 1 h. During the subsequent wash-out with an amine-free solution for 2 h, the neuronal efflux of noradrenaline declined mono-exponentially with a mean halftime of 42 min. Both Na+-free solution and ouabain caused facilitation of the efflux which thereafter declined in a multi-exponential fashion. The maximum facilitation was reached after 3 min of Na+-free perfusion and 25 min after introduction of ouabain. The amount of exogenous noradrenaline accumulated in the heart was only partially released when the extracellular Na+-concentration was nor…
RELEASE OF CATECHOLAMINES FROM THE HEART
1966
Publisher Summary This chapter discusses the release of catecholamines from the heart. The isolated heart of the rabbit with the sympathetic nervous supply from the right stellate ganglion intact was set up according to Hukovio and Muscholl. The ganglion was stimulated for 30 s at supramaximal voltage with rectangular impulses of 3–5 ms duration a frequency of 10 shocks/s. Each stimulation period was followed by a resting period of 30 s. In the rabbit, four doses of 50 mg/kg l-α-methyldopa decreased the noradrenaline concentration in auricles, right, and left ventricles by 38–60%. An equimolar amount of α-methyl noradrenaline was detected in the tissues. Reserpine and guanethidine in doses,…
Endotheliale Dysfunktion: Pathophysiologie, Diagnostik und prognostische Bedeutung
2008
The endothelium plays a crucial role in the regulation of vascular tone. Recent studies have indicated that endothelial dysfunction develops in the presence of cardiovascular risk factors such as hypertension, diabetes mellitus, hypercholesterolemia and in chronic smokers, as well as in patients with a family history of cardiovascular disease. It has now been established that endothelial dysfunction represents the first indicator of vascular damage. Endothelial function can be assessed in coronary and peripheral conductance and resistance vessels by means of invasive and noninvasive (ultrasound-guided) methods such as intracoronary infusion of acetylcholine, the endothelium-dependent vasodi…
Nitric Oxide Synthesis in Vascular Physiology and Pathophysiology
2015
Nitric oxide (NO) is produced by three NO synthase (NOS) isoforms: neuronal NOS (nNOS), inducible NOS (iNOS), and endothelial NOS (eNOS). Under physiological conditions, vascular NO is produced by eNOS and nNOS, with both playing atheroprotective roles. Under pathological conditions, iNOS can be induced and eNOS may become uncoupled. iNOS produces a large amount of NO, induces vascular dysfunction, and promotes atherogenesis. Uncoupled eNOS generates superoxide instead of NO and contributes significantly to endothelial dysfunction and atherogenesis. Major mechanisms of eNOS uncoupling include depletion of tetrahydrobiopterin, an essential co-factor for the eNOS enzyme, and deficiency of L-a…
Abstract 18540: Heme Oxygenase 1 Activity and Expression Suppresses a Proinflammatory Phenotype in Monocytes and Correlates With Endothelial Function…
2014
Background: Heme oxygenase-1 (HO-1) confers protection to the vasculature and suppresses inflammatory properties of monocytes and macrophages. It is unclear how HO-1 activity and expression determine the extent of vascular dysfunction in mice and humans. Methods and results: Decreasing HO activity was parallelled by decreasing aortic HO-1, eNOS and phospho-eNOS (ser1177) protein expression in HO-1 deficient mice, whereas aortic expression of nox2 showed a stepwise increase in HO-1+/- and HO-1-/- mice as compared to HO-1+/+ controls. Aortic superoxide formation increased depending on the extent of HO-1 deficiency and was blunted by the PKC inhibitor chelerythrine, indicating activation of t…
The Relationship Between Maximal Exercise-Induced Increases in Serum IL-6, MPO and MMP-9 Concentrations
2012
The aim of this study was to test the hypothesis that exercise would induce inflammatory response characterized by increased pro-inflammatory cytokines - interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α), adhesion molecule, matrix metalloprotease-9 (MMP-9) and myeloperoxidase (MPO) levels. Additional aim was to elucidate the possible source of maximal exercise-induced increase in MMP-9 concentration. To examine our hypothesis, 26 professional male ice hockey players [age 25 ± 1 (mean ± SEM) years; BMI 25.8 ± 0.4 kg/m(2) ] performed an incremental bicycle test until exhaustion, when maximal oxygen consumption was recorded. Venous blood samples were collected 30 min before and 2 min a…
NADPH Oxidase Accounts for Enhanced Superoxide Production and Impaired Endothelium-Dependent Smooth Muscle Relaxation in BKβ1 −/− Mice
2006
Objective— Nitric oxide (NO)-induced vasorelaxation involves activation of large conductance Ca 2+ -activated K + channels (BK). A regulatory BKβ1 subunit confers Ca 2+ , voltage, and NO/cGMP sensitivity to the BK channel. We investigated whether endothelial function and NO/cGMP signaling is affected by a deletion of the β1-subunit. Methods and Results— Vascular superoxide in BKβ1 −/− was measured using the fluorescent dye hydroethidine and lucigenin-enhanced chemiluminescence. Vascular NO formation was analyzed using electron paramagnetic resonance (EPR), expression of NADPH oxidase subunits, the endothelial NO synthase (eNOS), the soluble guanylyl cyclase (sGC), as well as the activity a…