Search results for "nitric Oxide"
showing 10 items of 1075 documents
Mechanisms involved in the relaxant action of testosterone in the renal artery from male normoglycemic and diabetic rabbits.
2009
Kidney disease is a frequent complication in diabetes, and significant differences have been reported between male and female patients. Our working hypothesis was that diabetes might modify the vascular actions of testosterone in isolated rabbit renal arteries and the mechanisms involved in these actions. Testosterone (10(-8) to 10(-4)M) induced relaxation of precontracted arteries, without significant differences between control and diabetic rabbits. Both in control and diabetic rabbits endothelium removal inhibited testosterone relaxant action. In arteries with endothelium, incubation with indomethacin (10(-5)M), N(G)-nitro-l-arginine (10(-5)M) or tetraethylammonium (10(-5)M) did not modi…
Vascular Dysfunction in Streptozotocin-Induced Experimental Diabetes Strictly Depends on Insulin Deficiency
2010
<i>Objective:</i> In previous studies we and others have shown that streptozotocin (STZ)-induced diabetes in rats is associated with vascular oxidative stress and dysfunction. In the present study, we sought to determine whether vascular dysfunction and oxidative stress strictly depend on insulin deficiency. <i>Methods:</i> The effects of insulin (2.5 U/day s.c., 2 weeks) therapy on vascular disorders in STZ-induced (60 mg/kg i.v., 8 weeks) diabetes mellitus (type I) were studied in Wistar rats. The contribution of NADPH oxidase to overall oxidative stress was investigated by in vivo (30 mg/kg/day s.c., 4 days) and in vitro treatment with apocynin. <i>Results:&…
AT1-receptor blockade by telmisartan upregulates GTP-cyclohydrolase I and protects eNOS in diabetic rats.
2008
Several enzymatic sources of reactive oxygen species (ROS) were described as potential reasons of eNOS uncoupling in diabetes mellitus. In the present study, we investigated the effects of AT1-receptor blockade with chronic telmisartan (25 mg/kg/day, 6.5 weeks) therapy on expression of the BH4-synthesizing enzyme GTP-cyclohydrolase I (GCH-I), eNOS uncoupling, and endothelial dysfunction in streptozotocin (STZ, 60 mg/kg iv, 7 weeks)-induced diabetes mellitus (type I). Telmisartan therapy did not modify blood glucose and body weight. Aortas from diabetic animals had vascular dysfunction as revealed by isometric tension studies (acetylcholine and nitroglycerin potency). Vascular and cardiac RO…
Involvement of prostacyclin and potassium channels in the diabetes-induced hyporeactivity of the rabbit carotid artery to B-type natriuretic peptide
2012
The relation between diabetes and stroke is bidirectional: diabetes is an important risk factor for ischemic stroke, and acute stroke frequently induces hyperglycemia. On the other hand, plasma B-type natriuretic peptide (BNP) levels are raised in diabetes and stroke. The purpose was to study how alloxan-induced diabetes might modify the effects of BNP in rabbit carotid arteries and the mechanisms involved in such actions. To do this, isometric tension in isolated rabbit carotid artery was recorded and prostanoids release and plasma NT-proBNP were measured by enzyme immunoassay. BNP induced a relaxation of phenylephrine-precontracted carotid arteries, and this relaxation was lower in diabet…
Protein oxidation in a group of subjects with metabolic syndrome.
2013
Abstract Aims To examine the protein oxidation, marker of the oxidative stress, in metabolic syndrome (MS). Methods We enrolled 106 subjects (45 women and 61 men) with MS of which 43 (14 women and 27 men) were with diabetes mellitus and 63 (31 women and 32 men) were without diabetes mellitus, and 54 subjects (19 women and 35 men) as control group. The protein oxidation, expressed as carbonyl groups, was measured by an enzyme-like immunosorbent assay (ELISA) kit (BioCell PC test kit, Enzo Life Sciences AG, Switzerland). Results In the whole group of MS subjects, in comparison with control group, a significant increase in carbonyl groups was present. The same datum was also evident between co…
Vascular Dysfunction in Experimental Diabetes Is Improved by Pentaerithrityl Tetranitrate but Not Isosorbide-5-Mononitrate Therapy
2011
OBJECTIVE Diabetes is associated with vascular oxidative stress, activation of NADPH oxidase, and uncoupling of nitric oxide (NO) synthase (endothelial NO synthase [eNOS]). Pentaerithrityl tetranitrate (PETN) is an organic nitrate with potent antioxidant properties via induction of heme oxygenase-1 (HO-1). We tested whether treatment with PETN improves vascular dysfunction in the setting of experimental diabetes. RESEARCH DESIGN AND METHODS After induction of hyperglycemia by streptozotocin (STZ) injection (60 mg/kg i.v.), PETN (15 mg/kg/day p.o.) or isosorbide-5-mononitrate (ISMN; 75 mg/kg/day p.o.) was fed to Wistar rats for 7 weeks. Oxidative stress was assessed by optical methods and o…
Synergistic interaction of adenylate cyclase activators and nitric oxide donor SIN-1 on platelet cyclic AMP
1995
Abstract The molecular mechanism of the synergistic platelet inhibition by activators of adenylate cyclase and guanylate cyclase in human platelets was investigated. The adenylate cyclase activators iloprost and prostaglandin E 1 and the guanylate cyclase activator 3-morpholino-synonimine (SIN-1) dose-dependently inhibited thrombin-induced aggregation of washed human platelets. Furthermore, SIN-1 at a concentration inhibiting platelet aggregation by only 10% shifted the IC 50 values of iloprost and prostaglandin E 1 by one order of magnitude to the left, indicating a synergistic action of adenylate cyclase and guanylate cyclase activators. Iloprost and prostaglandin E 1 dose-dependently ele…
Increased Platelet Sensitivity toward Platelet Inhibitors during Physical Exercise in Patients with Coronary Artery Disease
1999
Generalized atherosclerosis and coronary artery disease (CAD) are associated with endothelial dysfunction and during acute myocardial ischemia platelet activation has been reported. Activated platelets exert activated fibrinogen receptors (GP IIb/IIIa) and express CD 62p being regarded as reliable marker for platelet activation. Patients with angiographically proven CAD performed a bicycle exercise test until the onset of angina or ST-segment depression. We studied the ischemia-induced alterations in fibrinogen binding to activated platelet GP IIb/IIIa receptors and CD 62p expression. Therefore, the basal fibrinogen binding to GP IIb/IIIa and CD 62p expression and the thrombin-concentration…
Heme oxygenase-1 induction and regulation in unstimulated mouse peritoneal macrophages
2003
Heme oxygenase-1 (HO-1) is a stress protein induced by a variety of stimuli in inflammatory cells. This study was set up to investigate the induction of this protein in unstimulated macrophages. Resident mouse peritoneal macrophages purified by adhesion and cultured in basal conditions strongly induced HO-1 in a time-dependent manner, with a peak at 20 hr. At the same time, low levels of nitrite accumulated in the culture medium and expression of nitric oxide synthase-2 (NOS-2) and NOS-3 protein was detected. Inhibition of NO production and/or NOS expression by incubating macrophages with different drugs inhibiting NOS activity or modulating the redox state of the cell, such as N-acetylcyst…
Regulation and role of nitric oxide production in Arabidopsis thaliana defense responses induced by oligogalacturonides
2014
SPEIPM; International audience