Search Results
Results 401 - 450 of 1219
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Calò Lorenzo A - - 2002
In patients with cyclosporine-induced hypertension, upregulation of the nitric oxide system and oxidative stress were shown, which could induce hypertension, remodeling, and chronic rejection by increasing nitric oxide catabolism. However, it is still debated whether cyclosporine and tacrolimus exert a different action. The aim of the current study was to ...
Donmez Gulzade - - 2002
Several recent studies have shown that essential hypertension is associated with increased oxidative stress, which may cause hypertension via enhanced oxidation and inactivation of nitric oxide. In this study, we investigated the malondialdehyde, nitric oxide, and glutathione levels in newly diagnosed essential hypertensive patients and whether or not there was ...
Mas Manuel - - 2002
A wealth of pharmacological studies suggest that nitric oxide (NO) generated in the corpus cavernosum is a main molecular mediator of penile erection. However, the physiological levels of NO in the corpora and their possible changes during penile erection have remained unknown for want of suitable methodologies. We have adapted ...
Ghofrani Hossein Ardeschir - - 2002
BACKGROUND: Lung fibrosis can be complicated by pulmonary hypertension, limiting exercise tolerance and life expectancy. Furthermore, vasodilators might cause deterioration in gas exchange. Our aim was to compare acute effects of sildenafil, nitric oxide, and epoprostenol in individuals with pulmonary hypertension secondary to lung fibrosis. METHODS: We did a randomised ...
Viaro Fernanda - - 2002
Clinical and experimental observations prove that heparin-neutralizing doses of protamine increase pulmonary artery pressures and decrease systemic BP. Protamine also increases myocardial oxygen consumption, cardiac output, and heart rate, and decreases systemic vascular resistance. These cardiovascular effects have clinical consequences that have justified studies in this area. Protamine adverse reactions ...
Zhang Guoliang - - 2002
OBJECTIVE: To study the effects of cardiovascular function in dental extraction on hypertensive patients by inhalation 50% nitrous oxide. METHODS: The 30 hypertensive patients were randomly allocated into two groups: A group inhalation the 50% nitrous oxide and oxygen, B group inhalation the air and O(2). To measured the HR, ...
Shi Yang - - 2002
Chronic hypoxia increases endothelial nitric oxide synthase (eNOS) production of nitric oxide (*NO) and cardioprotection in neonatal rabbit hearts. However, the mechanism by which this occurs remains unclear. Recent studies suggest that heat shock protein 90 (hsp90) alters eNOS function. In the present study, we examined the role of hsp90 ...
Hayward Christopher S - - 2002
OBJECTIVES: The study was done to determine whether radial artery applanation tonometry can be used as a noninvasive method of assessing global endothelial function. BACKGROUND; It is known that beta(2)-receptor stimulation results in endothelial release of nitric oxide. Furthermore, for over a century glyceryl trinitrate (GTN) has been known to ...
Mizutani Ken-Ichi - - 2002
OBJECTIVE: A recent study demonstrated that free radicals were involved in the maintenance of hypertension in stroke-prone spontaneously hypertensive rats (SHRSP). Advanced glycation end-products (AGEs) accumulate progressively in the vasculature with ageing, and have been identified to be relevant mediators for various vascular complications. To elucidate the role of AGEs ...
Bates Kathryn - - 2002
Congestive heart failure (CHF) after myocardial infarction is associated with diminished endothelial nitric oxide (NO)-mediated vasorelaxation. The 3-hydroxy-3-methylglutaryl-CoA reductase inhibitors have been shown to modulate vascular tone independent of the effects on lipid lowering. We hypothesized that simvastatin restores NO-dependent vasorelaxation with CHF. We found that incubation of the normal ...
Saari Jack T - - 2002
Nitric oxide (NO)-mediated vasodilation is diminished in blood vessels of copper (Cu)-deficient rats. This study examined whether Cu deficiency affects blood pressure regulation via an effect on NO metabolism. Male, weanling rats were fed diets ranging from 0.4 to 7.2 mg Cu/kg diet for 5 weeks. Blood pressure was measured ...
Khalil Raouf A - - 2002
Normal pregnancy is associated with reductions in total vascular resistance and arterial pressure possibly due to enhanced endothelium-dependent vascular relaxation and decreased vascular reactivity to vasoconstrictor agonists. These beneficial hemodynamic and vascular changes do not occur in women who develop preeclampsia; instead, severe increases in vascular resistance and arterial pressure ...
Jonsson Lena M - - 2002
Nitric oxide is a major vasorelaxant and regulator of the blood pressure. The blood vessels contain several active sources of the superoxide radical, which reacts avidly with nitric oxide to form noxious peroxynitrite. There are large amounts of extracellular-superoxide dismutase (EC-SOD) in the vascular wall. To evaluate the importance of ...
Kazama Atsushi - - 2002
We examined the responses of pressurized bovine retinal functional arterioles (97-185 microm in diameter and approximately 3 mm long) to vasoactive substances and the mode of action of acetylcholine (ACh) on the pressurized arterioles. The retinal arterioles were cannulated at both ends with glass micropipettes and perfused at a constant ...
Neufeld Arthur H - - 2002
PURPOSE: To test the hypothesis that nitric oxide, synthesized by inducible nitric oxide synthase, causes degeneration of retinal ganglion cells in an animal model of glaucoma. METHODS: Rats with unilateral, chronic, moderately elevated intraocular pressure were treated orally with L-N(6)-(1-iminoethyl)lysine 5-tetrazole amide, a prodrug of an inhibitor of inducible nitric ...
Whitworth Judith A - - 2002
The blood pressure-raising effects of adrenocortical steroids with predominantly glucocorticoid activity, both naturally occurring and synthetic, are well known. Recent evidence suggests that the nitric oxide system plays a key role in the hypertension produced by glucocorticoids. Glucocorticoid actions at various sites in the nitric oxide synthase (NOS) pathway may ...
Chowdhary S - - 2002
Nitric oxide synthase is expressed in the sino-atrial node and animal data suggests a direct role for nitric oxide on pacemaker activity. Study of this mechanism in intact humans is complicated by both reflex and direct effects of nitric oxide on cardiac autonomic control. Thus, we have studied the direct ...
Sitniewska Ewa Maria - - 2002
The modulation by condition of the lack or the excess of nitric oxide (NO) on cardiovascular action of secretin in diabetic rats was investigated. In vitro the isolated heart function and in vivo, the systolic (SBP), diastolic (DSP) blood pressure and heart rate (HR) were measured. Secretin evoked inotropic positive ...
Kearney Mark T - - 2002
Circulating free fatty acids (FFA) are elevated in subjects with insulin resistance and Type II diabetes, and increase during myocardial ischaemia, but their haemodynamic effects are incompletely understood. During an investigation of the effects of FFA on endothelial function, we administered lipid emulsion (150 mg x min(-1) of soybean oil) ...
Higashi Yukihito - - 2002
The purpose of this study was to determine whether there are differences in the restoration of endothelial function by angiotensin-converting enzyme inhibition based on the severity of hypertension. Forearm blood flow (FBF) was measured in 69 patients with essential hypertension (mild, n = 23; moderate, n = 29; and severe, ...
Tanioka Hideki - - 2002
We examined modulation by nitric oxide (NO) of sympathetic neurotransmitter release and vasoconstriction in the isolated pump-perfused rat kidney. Electrical renal nerve stimulation (RNS; 1 and 2 Hz) increased renal perfusion pressure and renal norepinephrine (NE) efflux. Nonselective NO synthase (NOS) inhibitors [N(omega)-nitro-L-arginine methyl ester (L-NAME) or N(omega)-nitro-L-arginine], but not ...
Bayorh M A - - 2002
Cardiovascular deconditioning, sometimes manifested in astronauts during standing postflight, may be related to the impairment of autonomic function and/or excessive production of endothelium-dependent relaxing factors. In the present study, we examined the cardiovascular responses to 7-day 30 degrees tail-suspension and a subsequent 6-h post-suspension period in conscious male Sprague-Dawley rats ...
On Young-Keun - - 2002
The endothelium plays an important role in maintaining vascular tone and function. Essential hypertension is associated with alterations in endothelial function. The effects of antihypertensive agents on endothelial function have not been fully evaluated in human hypertension and data on the forearm circulation of humans are controversial. The aim of ...
Fukumoto Koji - - 2002
BACKGROUND/PURPOSE: The heart and kidney are both affected in sepsis-related multiple organ failure. Both utilize fatty acid substrates during the neonatal period, and impairment of oxidative metabolism during sepsis could lead to bioenergetic failure. The enzyme carnitine palmitoyl transferase I (CPT I) is important in the control of fat oxidation ...
Weidong S - - 2002
1. Broilers were divided at 42 to 44 d of age into a Control group (n=30) and a Treatment group (n=30). The mean pulmonary arterial pressure (mPAP) and electrocardiogram (ECG) leads II and aV(F) were measured 1, 2 and 4 h after an intravenous injection of 0.9% saline (Control group) ...
Törnberg D C F - - 2002
Nitric oxide (NO) is produced at different sites in the human airways and may have several physiological effects. Orally-produced NO seems to contribute to the levels found in exhaled air. Autoinhalation of nasal NO increases oxygenation and reduces pulmonary artery pressure in humans. The aim of this study was to ...
Eisenach John H - - 2002
To determine whether endothelial function is altered by chronic surgical sympathectomy, we infused ACh, isoproterenol, nitroprusside (NTP), and the nitric oxide synthase inhibitor NG-mono-methyl-L-arginine (L-NMMA) into the brachial arteries of nine patients 5-64 mo after thoracic sympathectomy for hyperhidrosis. Age- and gender-matched controls were also studied. Forearm blood flow (FBF) ...
Brook Robert D - - 2002
BACKGROUND: Fine particulate air pollution and ozone are associated with increased cardiovascular events. To help explain the mechanism behind these observations, we investigated the effect of air pollution exposure on vascular function. METHODS AND RESULTS: Twenty-five healthy adults underwent a randomized, double-blind, crossover study comparing the vascular response to the ...
Wilcox Christopher S - - 2002
Oxidative stress in blood vessels and the kidney in hypertension can be induced by diverse vasoconstrictor mechanisms, including blockade of nitric oxide synthase and activation of angiotensin II type I receptors and thromboxane receptors. It can cause vasoconstriction via bioinactivation of nitric oxide, and by nitric oxide synthase independent mechanisms ...
Suessenbacher Astrid - - 2002
Oxygen-derived free radicals and oxidants (reactive oxygen intermediates, ROI) have been implicated in cardiovascular diseases. The protective role of nitric oxide (NO) against ROI-mediated tissue injury is not resolved. We tested the effects of exogenous NO, L- and D-arginine and a NO synthase inhibitor on electrolysis-induced cardiac injury and the ...
Fu Wei Yu - - 2002
Homocysteine is a significant but modifiable risk factor for vascular diseases. While several pathological processes may be involved, homocysteine can cause significant endothelial impairment and compromise vascular NO bioactivity. In the present study, we aimed to assess effects of homocysteine on NO-mediated hemodynamic responses in vivo. We created an acute ...
Takagawa Yoshitoki - - 2002
To investigate the vascular endothelial dysfunction in the insulin resistance syndrome, muscarinic and alpha2-adrenergic mediated relaxations were studied in the fructose-fed rat. Male Sprague-Dawley rats were fed either fructose-rich chow (FFR, n=14) or normal chow (CNT, n=13) for 8 weeks. Systolic blood pressure (SBP) was measured by the tail-cuff method. ...
Platzack Björn - - 2002
The structures and biological activities of the isoforms of endothelin (ET) in a reptile are unknown. ET-3, whose primary structure is identical to human ET-3 except for the substitution Phe4 --> Tyr, and a peptide identical to human ET-1 were isolated from an extract of the lung of the alligator, ...
Higashi Yukihito - - 2002
There is little information concerning the interaction of nitric oxide and norepinephrine (NE) on endothelial function in humans. The purpose of this study was to determine whether endothelial function is impaired by NE secreted from patients with pheochromocytoma (pheo) and whether surgical resection of the tumor improves endothelial function in ...
Mizusawa Hiroya - - 2002
PURPOSE: alpha-Melanocyte stimulating hormone (alpha-MSH; Fluka Chemie AG, Geneva, Switzerland) and oxytocin induce erection in rats after intracerebroventricular administration. We studied possible interactions of alpha-melanocyte stimulating hormone with mechanisms pertaining to oxytocin or nitric oxide. MATERIALS AND METHODS: We used 78 anesthetized male Sprague-Dawley rats. Catheters were implanted in the ...
Wilkinson Ian B - - 2002
OBJECTIVE: Human urotensin II (hUII) is an endocrine hormone that acts as a potent arterial vasoconstrictor in both in vitro and in vivo studies in animals. We examined, for the first time, the local and systemic hemodynamic response to hUII in man in vivo. METHODS: Four healthy male volunteers took ...
Sazova O - - 2002
In accordance with the data reporting the identification of nitric oxide synthase (NOS) and vasoactive intestinal polypeptide (VIP) positive nerve fibres in the trabecular meshwork of the corpus cavernosum, we suggest that nitric oxide (NO) and VIP may serve complementary physiological roles in penile erection. Therefore SIN-1 and VIP were ...
Schildmeyer Lisa A - - 2002
Whereas the actual identity of endothelium-derived hyperpolarizing factor (EDHF) is still not certain, it involves a process requiring the endothelium and eliciting hyperpolarization and relaxation of smooth muscle. It is neither nitric oxide (NO) nor prostacyclin, and its presence has been demonstrated in a variety of vessels. Recent studies in ...
Buckley Christine - - 2002
Vascular risk factors, and particularly vasospasm, are thought to play a part in the pathogenesis of normal pressure glaucoma (NPG). This study aimed to determine whether the function of systemic resistance arteries was altered in patients with NPG. Contractile and relaxant function was assessed in arteries dissected from gluteal fat ...
Wu W C - - 2002
Increasing evidence has demonstrated that nitric oxide (NO) is involved in central cardiovascular regulation. In this study, we directly measured extracellular NO levels, in real-time, in the nucleus tractus solitarius (NTS) of anesthetized cats using Nafion/Porphyrine/o-Phenylenediamine-coated NO sensors. We found that local application of L-arginine (L-Arg) induced NO overflow in ...
Pleiner Johannes - - 2002
Impaired response to catecholamines contributes to the altered hemodynamics in sepsis, which has been attributed to excessive NO formation. We have studied the systemic hemodynamic and local forearm responses and inducible NO synthase (iNOS) expression during experimental endotoxemia in humans. Escherichia coli endotoxin (lipopolysaccharide [LPS]) was administered at doses of ...
Witlin Andrea G - - 2002
OBJECTIVE: The objective of this study was to determine neonatal growth, fertility, and blood pressure for offspring of pregnant rats following in utero exposure to L-omega nitro-L-arginine methyl ester (L-NAME). STUDY DESIGN: Osmotic mini-pumps were inserted on day 14 of gestation during the index pregnancy to deliver L-NAME (50 mg/day/rat) ...
Gerová M - - 2002
The question was addressed of how nitric oxide synthase (NO synthase) inhibition-induced hypertension in rat parents would affect the cardiovascular system in their offsprings. Two experimental groups were set up: Group I -- offsprings of parents who had both been administered NO synthase inhibitor L-nitro-arginine methyl ester (L-NAME 40 mg/kg/day) ...
Vaziri Nosratola D - - 2002
Chronic renal failure (CRF) is associated with oxidative stress which promotes production of reactive carbonyl compounds and lipoperoxides leading to the accumulation of advanced glycation and lipoxidation end products. Reactive oxygen species (ROS) avidly reacts with nitric oxide (NO) producing cytotoxic reactive nitrogen species capable of nitrating proteins and damaging ...
Berger Elke D - - 2002
BACKGROUND: Nitric oxide (NO) plays an important role in the regulation of blood pressure and renal hemodynamics. METHODS: To further investigate the role of NO in human hypertension, we studied the effect of systemic injection of N(G)-monomethyl-L-arginine (L-NMMA) on renal hemodynamics, urinary sodium excretion (FE(Na)), systemic hemodynamics and several vasoactive ...
Chowdhary Saqib - - 2002
Cardiac vagal control has prognostic significance in cardiac disease, but the control mechanisms of this system remain poorly understood. We have previously demonstrated a role for NO in promoting vagal control of heart rate in humans. Here we examine the influence of L-arginine, the substrate for NO synthase, on this ...
Cebeci Sevsen Altinay - - 2002
The purpose of this study was to investigate the effects of acute nitric oxide synthase inhibition on mean arterial blood pressure, oxidative stress markers such as plasma malondialdehyde (MDA) concentration, intracellular antioxidant enzyme activities such as copper-zinc superoxide dismutase (Cu/Zn SOD) and catalase and on trace elements important for activity ...
Piech A - - 2002
Because nitric oxide (NO) regulates cardiac and vessel contraction, we compared the expression and activity of the endothelial NO synthase (eNOS) and caveolin, which tonically inhibits eNOS in normal and hypertrophic cardiomyopathic hearts. NOS activity (L-[(3)H]citrulline formation), eNOS immunostaining, and caveolin abundance were measured in heart tissue of 23 mongrel ...
Vág J - - 2002
We reported previously that the nitric oxide synthesis inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME) decreases cardiac output. Several studies have shown that inhibition of nitric oxide synthesis decreases the heart rate. In the present study, we investigated the effect of a single bolus administration of L-NAME on blood pressure and heart ...
Klinger James R - - 2002
The role of nitric oxide (NO) in numerous physiologic systems only recently has been discovered. When used as a gas, inhaled NO (iNO) has many unique properties that cause immediate improvements in pulmonary hemodynamics and oxygenation. Acute benefits in physiologic parameters have been demonstrated in numerous studies of iNO in ...
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