Search results for "VASODILATION"
showing 10 items of 228 documents
Role of nitric oxide synthase isoforms for ophthalmic artery reactivity in mice.
2014
Abstract Nitric oxide synthases (NOS) are involved in regulation of ocular vascular tone and blood flow. While endothelial NOS (eNOS) has recently been shown to mediate endothelium-dependent vasodilation in mouse retinal arterioles, the contribution of individual NOS isoforms to vascular responses is unknown in the retrobulbar vasculature. Moreover, it is unknown whether the lack of a single NOS isoform affects neuron survival in the retina. Thus, the goal of the present study was to examine the hypothesis that the lack of individual nitric oxide synthase (NOS) isoforms affects the reactivity of mouse ophthalmic arteries and neuron density in the retinal ganglion cell (RGC) layer. Mice defi…
Oxidative stress in cardiovascular disease: successful translation from bench to bedside?
2007
Over the last decades, sound evidence has been generated that oxidative stress is one of the most potent inductors of endothelial dysfunction and is involved at all stages of atherosclerotic plaque evolution.1,2 Experimental and animal models provide a clear association between the amount of oxidative challenge and reversible vascular dysfunction that can be observed before permanent alterations of the vessel wall occur. Article p 1367 Important for cardiovascular biology is the consumption of nitric oxide (NO) by reactive oxygen species. Endothelium relaxant factor is a central molecule in vascular homeostasis as a modulator of endothelial tone and reactivity.3 It is produced by NO synthas…
Raloxifene increases the capacity of serum to promote prostacyclin release in human endothelial cells: implication of COX-1 and COX-2.
2004
OBJECTIVE Prostacyclin is a potent vasodilator synthesized by two isoforms of cyclooxygenase in endothelium. The aim of this study was to investigate the effect of serum from postmenopausal women treated with raloxifene on prostacyclin production by human umbilical vein endothelial cells and on cyclooxygenases-1 and -2. DESIGN Serum was collected from 21 women receiving 60 mg/day of raloxifene, at baseline and at 3 and 6 months. Human umbilical vein endothelial cells were exposed to serum for 24 hours, and prostacyclin production was evaluated in supernatants. Selective inhibitors of cyclooxygenases-1 and -2 (SC-560 and NS-398) were used to investigate the relative contribution of each enzy…
Gathering of aging and estrogen withdrawal in vascular dysfunction of senescent accelerated mice.
2010
The aim of this work was to characterize a mouse model of experimental menopause and cardiovascular aging that closely reflects menopause in women. Senescence accelerated mouse (SAM)-Resistant type 1 (SAMR1, n=30) and SAM-Prone type 8 (SAMP8, n=30) were separated at 5months of age into three groups: 1) sham-operated (Sham); 2) ovariectomized (Ovx); and 3) ovariectomized chronically-treated with estrogen (Ovx+E2). Contractile responses to KCl (60mM) and thromboxane A(2) were greater in aorta from SAMP8 mice compared with SAMR1 in all groups. Neither ovariectomy nor estrogen replacement modified the contractile responses from SAMR1 mice. Conversely, in Ovx SAMP8 the increased maximal contract…
Immunohistochemical and Biomolecular Identification of Orphanin FQ, eNOS, Atrial natriuretic Factor and Oxytocin in Rat Seminal Vesicles
2009
In previous studies performed on rodents, we detected the presence of adreno-cholinergic and peptidergic innervation in seminal vesicles and other organs of the male genital system, such as prostate and ductus deferens, in which we also investigated the expression of NOS and NADPH-diaphorase. During the present project we focused our attention on the expression of some peptides involved in local control of smooth muscle relaxation, contractility, vasodilatation and control of blood flow in rat seminal vesicles. We investigated, through immunohistochemistry and RT-PCR, the presence of four peptides: orphanin, eNOS, ANF and oxytocin. Immunohistochemistry was used to detect the presence of the…
Regulation of NOS expression in vascular diseases
2020
Nitric oxide synthases (NOS) are the major sources of nitric oxide (NO), a small bioactive molecule involved in the regulation of many cellular processes. One of the most prominent functions of NO is regulation of vasodilatation and thereby control of blood pressure. Most important for vascular tone is NOS3. Endothelial NOS3-generated NO diffuses into the vascular smooth muscle cells, activates the soluble guanylate cyclase resulting in enhanced cGMP concentrations and smooth muscle cell relaxation. However, more and more evidence exist that also NOS1 and NOS2 contribute to vascular function. We summarize the current knowledge about the regulation of NOS expression in the vasculature by tra…
Organic Nitrate Therapy, Nitrate Tolerance, and Nitrate-Induced Endothelial Dysfunction: Emphasis on Redox Biology and Oxidative Stress
2015
Abstract Organic nitrates, such as nitroglycerin (GTN), isosorbide-5-mononitrate and isosorbide dinitrate, and pentaerithrityl tetranitrate (PETN), when given acutely, have potent vasodilator effects improving symptoms in patients with acute and chronic congestive heart failure, stable coronary artery disease, acute coronary syndromes, or arterial hypertension. The mechanisms underlying vasodilation include the release of •NO or a related compound in response to intracellular bioactivation (for GTN, the mitochondrial aldehyde dehydrogenase [ALDH-2]) and activation of the enzyme, soluble guanylyl cyclase. Increasing cyclic guanosine-3′,-5′-monophosphate (cGMP) levels lead to an activation of…
Red Wine and Cardiovascular Health
2012
There is strong epidemiological evidence that light-to-moderate consumption of alcoholic drinks, but neither zero nor more than moderate intake, reduces mortality from all causes and also diminishes cardiovascular risk.1 The lowest risk for coronary heart disease mortality is seen with 1 to 2 drinks (12.5–25g alcohol) per day. Article, see p 1065 Hypertension is a major risk factor for cardiovascular disease, and there is a clear inverse relationship between light-to-moderate alcohol intake and blood pressure. Thus, the reduced cardiovascular risk associated with moderate consumption of alcoholic drinks may be due, in part, to a reduction in blood pressure. The greatest blood pressure benef…
When the Pd/Pa Is Already Significant: A “Quick and Clean” FFR
2016
The assessment of FFR for a single stenosis may also be rapid and not require hyperemia if the Pd/Pa gradient already reaches significance before the vasodilator is administered. In this case the resting Pd/Pa was 0.45, demonstrating that the stenosis was relevant even before hyperemia was achieved.
Selenium supplementation improves antioxidant capacity in vitro and in vivo in patients with coronary artery disease
2008
Background Selenium is a central determinant of antioxidative glutathione peroxidase 1 (GPx-1) expression and activity. The relevance of selenium supplementation on GPx-1 in coronary artery disease (CAD) needs to be established. We assessed the effect of selenium supplementation on GPx-1 in cell culture and on endothelial function in a prospective clinical trial. Methods Human coronary artery endothelial cells were incubated with 5.78 to 578 nmol/L sodium selenite, Se-methyl-selenocysteine hydrochloride, or seleno-l-methionine. Glutathione peroxidase 1 mRNA and protein expression and activity were measured. Coronary artery disease patients (n = 465) with impaired endothelial function (flow-…