Search Results
Results 451 - 500 of 2901
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Gori Tommaso - - 2004
We investigated in healthy humans whether continuous therapy with organic nitrates impairs conduit artery responses to nitroglycerin (GTN) as well as its effects on endothelium-dependent vasodilation. Sixteen young male volunteers were randomized to continuous treatment with either transdermal GTN (0.6 mg/h/24 hrs for 6 days) or no therapy. Endothelium-dependent (flow-mediated) ...
Graziani Annarita - - 2004
OBJECTIVE: Cholesterol-rich membrane domains, which contain the scaffold protein caveolin-1 (Cav-1) (caveolae), represent an important structural element involved in endothelial signal transduction. The present study was designed to investigate the role of these signaling platforms in the generation of endothelial-derived hyperpolarizing factor (EDHF). METHODS: Caveolae were disrupted by cholesterol depletion ...
Belik Jaques - - 2004
Nitric oxide (NO) reacts with superoxide anion to form the peroxynitrite anion (ONOO-), a molecule with pulmonary vasodilator properties in the adult rat. The purpose of this study was to compare the effects of ONOO- on intrapulmonary arteries from the newborn (days 4-7), juvenile (day 14), and adult rat. Following ...
Buzun Leszek - - 2004
OBJECTIVE: Low molecular weight heparins (LMWHs) offer practical and potential pharmacological advantages over unfractionated heparin in multiple applications but have not been studied as vasoactive agents. The purpose of this study was to investigate the effects of two commercial preparations of LMWHs, enoxaparin sodium and nadroparin calcium, on vasoconstriction in ...
van der Harst Pim - - 2004
Persistent activation of the renin-angiotensin system leads to downregulation of the angiotensin type-1 receptor, and consequently, to a decreased response to exogenous angiotensin II. In the present study, we investigated the association of angiotensin II responsiveness to clinical outcome after coronary artery bypass grafting (CABG). We studied the responsiveness to ...
MacEachern Karen E - - 2004
OBJECTIVE: Hypoxaemia accompanies dorsal recumbency in the horse and frequently complicates general anaesthesia. The physiology associated with this phenomenon is poorly understood. One possible cause of poor tolerance to dorsal recumbency is an absent or reduced response to hypoxic pulmonary vasoconstriction (HPV). This study compared the HPV response in isolated ...
Ishida Hideyuki - - 2004
BACKGROUND:: Nipradilol (3,4-dihydro-8-[2-hydroxy-3-isopropyl-amino]propoxy-3-nitroxy-2-H-1-benzopyran), a potent non-selective beta-adrenoceptor antagonist, has been shown to increase NO production. The mechanisms are up-regulation of nitric oxide synthase (NOS) and direct release of NO from nipradilol. The process of direct NO release from nipradilol requires a reductase, such as glutathione S-transferase (GST) in some cells ...
Pretorius Mias - - 2004
BACKGROUND: This study tested the hypothesis that angiotensin-converting enzyme (ACE) inhibitors potentiate activation of the kallikrein-kinin system during cardiopulmonary bypass (CPB). METHODS: The effects of CPB on concentrations of bradykinin and its metabolite bradykinin 1-5 (BK1-5) were determined in 31 patients taking an ACE inhibitor who were randomized to continue ...
Cavalli Maurizio M Dipartimento di Farmacologia ed Anestesiologia, Università degli Studi di Padova, Largo E. Meneghetti 2, 35131 Padova, - - 2004
Norbormide is a vasoconstrictor of rat peripheral arteries and a relaxant in rat aorta. To characterise norbormide actions within the rat vascular tree we have investigated its effects on the contractile function of rings from several arteries and veins. A maximal norbormide concentration (50 microM) failed to contract thoracic aorta ...
Ruiz-Nuño Ana - - 2004
The vascular selectivity of PF9404C ((2'S),(2S)-3-isopropylamine,1-[4-(2,3-dinitroxy)propoxymethyl]-phenoxy-2'-propanol), a new beta-blocker with nitric oxide (NO)-donor and vasodilator properties, was studied in different rabbit arteries and veins. Phenylephrine (10(-6) M) or 35 mM K+ were used to pre-contract the arteries and veins prior to study the relaxant effects of PF9404C and nitroglycerin. The ...
Fukada Sandra Yasuyo - - 2004
The rabbit carotid artery, injured by silicone collar, presents a perivascular inflammatory response and alterations in vascular responsiveness. Considering that angiotensin II (Ang II) plays an important role in cardiovascular physiology and pathology and that cardiovascular disease increases in postmenopausal women, the aim of this study was to investigate whether ...
Lamarche Yoan - - 2004
OBJECTIVE: Endothelial dysfunction of the pulmonary arterial tree occurring after cardiopulmonary bypass (CPB) contributes to pulmonary hypertension and respiratory failure in the postoperative period. The goal of the present study was to characterize the alterations of endothelial cell signal transduction pathways in pulmonary arteries following CPB, the effect of ventilation ...
Gendron Marie-Eve - - 2004
The influence of left ventricular hypertrophy (LVH) on the endothelial function of resistance endocardial arteries is not well established. The aim of this study was to characterise the mechanisms responsible for UK-14,304 (alpha(2)-adrenoreceptor agonist)-induced endothelium-dependent dilation in pig endocardial arteries isolated from hearts with or without LVH. LVH was induced ...
Cehreli Murat Cavit - - 2004
The purpose of this study was to explore the effects of titanium dioxide (TiO(2)) on vascular smooth muscle contractility with the use of the rat carotid-artery model. TiO(2) powder was implanted on right carotid arteries of five albino rats, the left arteries of which were left intact and served as ...
Dessy C - - 2004
BACKGROUND: Coronary vessel tone is modulated in part by beta-adrenergic relaxation. However, the implication of specific beta-adrenoceptor subtypes and their downstream vasorelaxing mechanism(s) in human coronary resistance arteries is poorly defined. beta3-Adrenoceptors were recently shown to vasodilate animal vessels and are expressed in human hearts. METHODS AND RESULTS: We examined ...
Moreno Laura - - 2004
After birth and during the first days of extrauterine life, pulmonary arterial pressure is progressively reduced to reach the adult values. We hypothesized that changes in PDE5 activity might be involved in the pulmonary postnatal maturation of the nitric oxide (NO)/cGMP pathway. The PDE5 inhibitor sildenafil produced vasorelaxant responses in ...
Esther Rendal Vázquez M - - 2004
An established method for the cryopreservation of human femoral arteries for subsequent transplantation as allografts has been studied with particular attention to preservation of smooth muscle and endothelium. Human femoral arteries (HFAs) were harvested from multi-organ donors. Two groups were established; a control group of unfrozen HFAs and a group ...
Heinrich Marc - - 2004
RATIONALE AND OBJECTIVES: To investigate whether the lower incidence of vasodilatation upon vascular injection of iotrolan, as compared with monomeric contrast media, is solely the result of its isotonicity. MATERIALS AND METHODS: In an organ bath, isolated segments of swine renal arteries, uncontracted or precontracted by 10 microm phenylephrine, were ...
Wang Jong-Shyan - - 2004
OBJECTIVE: To investigate the effects of neuromuscular electric stimulation (NMES) on endothelial vascular control and hemodynamic function in patients in rehabilitation after acute stroke. DESIGN: Before-after trial. SETTING: Inpatients in a tertiary hospital. PARTICIPANTS: Sixteen stroke patients (11 women, 5 men) with a mean age of 60.6+/-19.5 years. INTERVENTIONS: All ...
Tarasova O - - 2004
This study was aimed at comparing the effect of 2-week tail suspension on the characteristics of median artery and saphenous artery isolated from forelimb and hindlimb, accordingly. The segments of arteries were mounted in two-channel myograph for recording their isometric wall tension. In post-suspension rats segments of saphenous artery showed ...
Taylor P D - - 2004
We recently reported vascular dysfunction in adult offspring of rats fed a fat-rich (animal lard) diet in pregnancy. This study reports further characterization of constrictor and dilator function in mesenteric and caudal femoral arteries from 180-day-old offspring of dams fed the high fat diet (OHF). Endothelium-dependent relaxation in response to ...
Ni Wei - - 2004
We tested the hypothesis that the 5-HT transporter (5-HTT) is present and functional in peripheral arterial smooth muscle. In aorta and mesenteric resistance arteries, real time RT-PCR and western analyses indicated the presence of 5-HTT mRNA and a 74 kDa 5-HTT protein. Immunohistochemistry localized the transporter to smooth muscle and ...
Gauthier Kathryn M - - 2004
Arachidonic acid metabolites contribute to the regulation of vascular tone and therefore tissue blood flow. The vascular endothelium metabolizes arachidonic acid by cytochrome P450 epoxygenases to epoxyeicosatrienoic acids or EETs. The placement of the epoxide group can occur on any of the double bonds of arachidonic acid resulting in four ...
Miller Alastair L - - 2004
Increased total plasma homocysteine is an independent risk factor for cardiovascular disease. This study was designed to determine whether it can impair endothelial function, by examining the recovery of acetylcholine-evoked relaxation following mechanical denudation of the endothelium in the arteries of cystathionine beta-synthase knockout (CbetaS(+/-)) mice. Heterozygous CbetaS(+/-) mice had ...
Zhang Rong-Zhen - - 2004
OBJECTIVE: We compared the basal and bradykinin (BK)-induced NO release and endothelium-derived hyperpolarizing factor-mediated function between coronary arteries and cardiac veins. METHODS AND RESULTS: Isolated coronary vessels (large arteries, cardiac veins as well as microvessels) were studied. An NO-specific electrode and a conventional intracellular glass microelectrode were used to directly ...
Jhaveri Rajiv - - 2004
Beta-adrenergic agonists (e.g., epinephrine [E] and norepinephrine [NE]) and phosphodiesterase-III inhibitors (e.g., milrinone) are often used in combination to augment ventricular function in the perioperative period. In the myocardium, milrinone acts synergistically with beta-adrenergic agonists to increase contractility. However, the potential interaction between catecholamines with combined alpha- and beta-adrenergic activity ...
Tsai Ben M - - 2004
Endothelial monocyte-activating polypeptide (EMAP) II is a novel proinflammatory cytokine that is released from apoptotic and hypoxic cells. The purpose of this study was to determine the effect of EMAP II on the pulmonary artery (PA) and to characterize its mechanism of action. To study this, isolated PA rings from ...
O'Sullivan Saoirse E - - 2004
1 In order to address mechanistic differences between arterial vessel types, we have compared the vasorelaxant actions of anandamide in resistance (G3) and conduit (G0) mesenteric arteries. 2 Anandamide produced concentration-dependent relaxations of pre-constricted G3 arteries with a maximal response that was significantly greater than seen in G0. 3 The ...
Springer Jochen - - 2004
Although airway and pulmonary vessel tone are regulated predominantly by cholinergic and adrenergic impulses, biologically active peptides such as calcitonin gene-related peptide (CGRP) may significantly influence human smooth muscle tone in normal and pathophysiological states. In the present study, the expression of CGRP and its receptor CGRPR-1 and the biological ...
Tessier Deron J - - 2004
PURPOSE: Sildenafil is an oral phosphodiesterase type 5 inhibitor that is a vasodilator used in the treatment of erectile dysfunction. Cyclic nucleotide-dependent vasorelaxation is associated with increases in the phosphorylation of the heat shock related protein 20 (HSP20). The purpose of this study was to determine if sildenafil-induced vasorelaxation is ...
Bennett R T - - 2004
BACKGROUND: Urotensin II (UII) has been identified as a ligand for the orphan receptor GPR14 through which it elicits potent vasoconstriction in humans and non-human primates. The pulmonary vasculature is particularly sensitive; human UII (hUII) exhibits a potency 28 times that of endothelin (ET)-1 in isolated pulmonary arteries obtained from ...
Taylor Mark S - - 2004
Cyclic GMP-dependent protein kinase (PKG) serves as an important physiological regulator of vascular reactivity and tone. However, available inhibitors of PKG have exhibited variable effects in intact tissue, hindering the elucidation of the functional role of PKG in blood vessels. In this study, we have determined the effects of our ...
Bolla Manlio - - 2004
The influence of cyclooxygenase pathway activation following thromboxane-endoperoxide (TP) receptor stimulation was studied in rat mesenteric resistance arteries (n=6 to 10 per group). We studied isolated, perfused, and pressurized mesenteric resistance arteries (mean internal diameter 214 microm) using an arteriograph, enabling us to study arteries in physiological conditions of flow ...
Kitazawa Toshio - - 2004
Ca(2+) sensitivity of arterial contractility is governed by regulating myosin phosphatase activity in response to agonist stimuli. CPI-17, a myosin phosphatase inhibitor phosphoprotein, is phosphorylated concomitantly with agonist-induced contractile Ca(2+) sensitization in mammalian artery. CPI-17 has not been detected in chicken artery, but is readily detectable in pigeon artery. To ...
Ishikawa Hitoshi - - 2004
We have investigated functional and morphological changes occurring in the wall of the hypercholesterolemic rabbit ciliary artery. A mutant rabbit with hypercholesterolemia and atherosclerosis was created by serial breeding. Ciliary arteries from hypercholesterolemic, age-matched control and young control rabbits' eyes were mounted in a myograph system. The effects of phenylephrine ...
Katai Rumi - - 2004
The direct actions of dopamine on human arterial coronary bypass grafts are not well known. We investigated its effects on isolated rings cut from radial arteries (RA), gastroepiploic arteries (GEA), and internal mammary arteries (IMA) harvested from patients undergoing coronary artery bypass surgery. Dopamine produced dose-dependent contractile responses in RA, ...
Accorsi-Mendonça D - - 2004
1. The effects of balloon injury on the reactivity of ipsilateral and contralateral carotid arteries were compared to those observed in arteries from intact animals (control arteries). 2. Carotid arteries were obtained from Wistar rats 2, 4, 7, 15, 30 or 45 days after injury and mounted in an isolated ...
Sanders Marijke - - 2004
A suboptimal fetal environment has been linked to increased risk of cardiovascular disease in adulthood. We investigated whether intrauterine stress (IUS) alters the development of adrenergic reactivity in different types of rat arteries. Intrauterine stress was induced by ligation of the uterine arteries at day 13 of pregnancy in Wistar ...
Hussain Monira B - - 2004
BACKGROUND AND PURPOSE: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is characterized by ultrastructural abnormalities in small cerebral and systemic vessels. We assessed vasomotor function in systemic small arteries in CADASIL. METHODS: We studied 10 CADASIL patients and 10 control subjects. Resistance arteries isolated from gluteal biopsies ...
Chicoine Louis G - - 2004
Nitric oxide (NO) is produced by NO synthase (NOS) from L-arginine (L-Arg). Alternatively, L-Arg can be metabolized by arginase to produce L-ornithine and urea. Arginase (AR) exists in two isoforms, ARI and ARII. We hypothesized that inhibiting AR with L-valine (L-Val) would increase NO production in bovine pulmonary arterial endothelial ...
Inan Saadet - - 2004
The combined action of morphine and dextromethorphan on the superior mesenteric artery was investigated in this study. The artery was cut into rings, placed in a muscle bath and mounted to a force transducer for recording tension. Rings preconstricted with 1 microM phenylephrine produced a dose-dependent relaxation to graded doses ...
Fogarty Jennifer A - - 2004
BACKGROUND: Chronic coronary occlusion (CCO) impairs endothelial function of distal collateral-dependent microvasculature; however, long-term exercise training (EX) seems to improve endothelial dysfunction. We hypothesized that EX enhances vasodilation responses to vascular endothelial growth factor (VEGF165), mediated via nitric oxide (NO), in arterioles exposed to CCO. METHODS AND RESULTS: The proximal ...
Stähli Barbara E - - 2004
The radial artery (RA) is increasingly used as coronary artery bypass graft. In rare cases, however, it is macroscopically atherosclerotic at time of harvest. We examined how the regulation of vascular tone is altered under such circumstances. Macroscopically evident atherosclerotic lesions were observed in 3 of 429 RA (0.7%) isolated ...
Josefsson Atli - - 2004
The effect of the carbonic anhydrase inhibitor dorzolamide on vascular smooth muscle in pre-contracted bovine retinal arteries was examined. Ring segments of retinal arteries were placed in a small vessel myograph for measurement of contractile activity. The arteries were placed in a physiological saline solution. Vasoconstriction was induced by either ...
Michel Frédéric - - 2004
The aim of the study was to investigate in vivo arterial reactivity in the mouse hind limb using Orthogonal Polarisation Spectral (OPS) imaging, which delivers high-contrast images of vascular beds by visualizing red blood cells. After minimal skin invasion of anesthetized mice, the OPS probe was placed on the hind ...
Discigil B - - 2004
To determine if radiocontrast impairs vascular relaxation of the renal artery, segments (4-5 mm in length) of canine renal artery were suspended in vitro in organ chambers to measure isometric force (95% O2/5% CO2, at 37 C). Arterial segments with and without endothelium were placed at the optimal point of ...
Paravicini Tamara M - - 2004
BACKGROUND AND PURPOSE: We examined the importance of NADPH-oxidase in reactive oxygen species production in cerebral arteries and its effect on vascular tone in vivo. Furthermore, we investigated whether chronic hypertension affects function or expression of this enzyme in cerebral vessels. METHODS: Superoxide generation was detected in isolated rat basilar ...
Sheykhzade Majid - - 2004
We investigated the type of desensitization of calcitonin gene-related peptide (CGRP)-induced responses in rat isolated intramural coronary arteries using isometric myograph and FURA-2 technique. In coronary arteries precontracted with 9,11-dideoxy-11alpha,9alpha-epoxymethanoprostaglandin F2alpha (U46619), development of tachyphylaxis to CGRP is characterized by significant attenuation of CGRP-induced maximal reduction in the tension and ...
Tsutsumi Yohsuke - - 2004
PURPOSE: Vasodilators are considered effective in the treatment of pulmonary hypertension if the vascular reactivity remains reversible. This study was designed to investigate the possibility that JTV-506, a new adenosine trisphoshate-sensitive potassium channel opener, may serve as a useful vasodilator in the treatment of pulmonary hypertension. METHODS: After approval by ...
Pataricza J - - 2004
Functional role of calcium-activated potassium (KCa) channels on the basal and agonist-elevated arterial tones was investigated in isolated rabbit aorta, porcine and canine coronary arteries as well as in human internal mammary artery. The vascular tones enhanced by contractile agents were increased further by preincubation of these conduit blood vessels ...
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