Search Results
Results 301 - 350 of 1224
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Schlaich Markus P - - 2004
BACKGROUND: It is unknown whether beta-adrenoceptor-mediated vasodilatation is altered in early hypertension and whether it can be modulated by L-arginine. METHODS AND DESIGN: We measured changes in forearm blood flow by plethysmography in response to acetylcholine (9 and 37 microg/min), sodium nitroprusside (200 and 800 ng/min) and the beta-receptor agonist, ...
Gokce Noyan - - 2004
Hypertension is a major healthcare problem afflicting nearly 50 million individuals in the United States. Despite its strong causal association with cardiovascular disease complications including myocardial infarction, heart failure, and stroke, the majority of patients with hypertension do not achieve optimal blood pressure control. The prevalence of hypertension is expected ...
Dhawan Vivek - - 2004
OBJECTIVE: Pregnancy is associated with profound alterations in the cardiovascular system, the long-term effects of which are unknown. Human epidemiological studies suggest that multiparity (multiple pregnancies) increases the risk of cardiovascular disease. The mechanisms underlying these findings remain to be elucidated. The objective of this study was to determine the ...
Chong Chee Fui - - 2004
BACKGROUND: Surgical preparation of coronary conduits may affect early and long-term patency through endothelial and smooth muscle injury. We investigated the effect of hydrostatic distention on the in vitro endothelial function and contractile properties of the human radial artery. METHODS: Human radial arteries were harvested and distended to physiologic pressure ...
Sercombe Richard - - 2004
We examined the effects of acute hyperglycemia on the function of rabbit cerebral arteries in vitro. It was hypothesized that increased formation of reactive oxygen species (ROS) could occur, which could explain how hyperglycemia aggravates certain pathologic situations such as cerebral ischemia. Three-millimeter basilar artery segments were incubated in either ...
Lockwood Jennifer M - - 2005
In normally active individuals, postexercise hypotension after a single bout of aerobic exercise occurs due to an unexplained peripheral vasodilation. Prostaglandin production has been suggested to contribute to the increases in blood flow during and after exercise; however, its potential contribution to postexercise hypotension has not been assessed. The purpose ...
Consolim-Colombo Fernanda M - - 2004
Endothelium may be damaged, especially at the coronary microcirculation, in animal models of Chagas' disease by several mechanisms. Endothelial dysfunction has been reported in chronic Chagas' heart disease patients with heart failure. Nevertheless, peripheral endothelial function has never been studied in patients with Chagas' heart disease without heart failure and ...
Lassègue Bernard - - 2004
Hypertension is associated with an elevation of reactive oxygen species (ROS) and frequently also with an impairment of endogenous antioxidant mechanisms. Experimental manipulation of the redox state in vivo shows that ROS can be a cause of hypertension. During the development of the disease, ROS are generated by endogenous sources, ...
Seebacher Frank - - 2004
Reptiles change heart rate and blood flow patterns in response to heating and cooling, thereby decreasing the behavioural cost of thermoregulation. We tested the hypothesis that locally produced vasoactive substances, nitric oxide and prostaglandins, mediate the cardiovascular response of reptiles to heat. Heart rate and blood pressure were measured in ...
Ruan Zonghai - - 2004
To compare the role of nitric oxide in an adaptive process to chronic hypoxia, we examined the effects of endogenous nitric oxide synthase inhibition on pulmonary vascular tone in conscious sheep and pigs living at high altitude. Unanesthetized male sheep (n = 6) and pigs (n = 5), born and ...
Guiraudou Pierre - - 2004
Amiodarone, a powerful antiarrhythmic compound, possesses coronary and peripheral vasodilator properties. The mechanisms responsible for these effects remain incompletely understood. In the present study, the coronary effects of amiodarone and dronedarone, a non-iodinated amiodarone-like compound, were investigated in isolated guinea pig hearts perfused at constant flow with high K+ solution ...
Dünser M W - - 2004
BACKGROUND: Arginine-vasopressin (AVP) can successfully stabilize hemodynamics in patients with advanced vasodilatory shock. It has been suggested that inhibition of cytokine-induced nitric oxide production may be an important mechanism underlying AVP-induced vasoconstriction. Therefore, serum concentrations of nitrite/nitrate (NOx), the stable metabolite of nitric oxide, were measured in patients suffering from ...
Wu Tianying - - 2004
Oxidative stress is hypothesized to play an important role in a variety of chronic diseases, but the short-term and long-term stability of measurements of biomarkers related to oxidative stress remains unclear. The objective of this study was to evaluate the stability of measurements of malondialdehyde (MDA), F2-isoprostanes, and fluorescent oxidation ...
Bazán-Perkins Blanca - - 2004
Barometric plethysmography for unrestrained animals is a non-invasive method that allows repetitive measurements of pulmonary function, but habituation of the conscious animal to this technique has not been explored. Respiratory frequency (f(R)) and 'enhanced pause' (P(enh)) were measured by barometric plethysmography for a period of 8 h in guinea-pigs. Compared ...
Pacher Pál - - 2004
Increased production of reactive oxygen and nitrogen species has recently been implicated in the pathogenesis of cardiac and endothelial dysfunction associated with atherosclerosis, hypertension, and aging. Oxidant-induced cell injury triggers the activation of nuclear enzyme poly(ADP-ribose) polymerase (PARP), which in turn contributes to cardiac and vascular dysfunction in various pathophysiological ...
Ghofrani Hossein A - - 2004
Pulmonary hypertension (PH) is a disease of various origins. Nitric oxide-a potent vasodilator-is a key player of pulmonary vasoregulation. Nitric oxide signaling is mainly mediated by the guanylate cyclase/cyclic guanylate monophosphate pathway. The effects of this second messenger system are limited by enzymatic degradation through phosphodiesterases (PDEs). Recently, beneficial effects ...
Sigaudo-Roussel Dominique - - 2004
Pressure-induced vasodilation (PIV) is a mechanism whereby skin blood flow increases in response to progressive locally applied pressure. Skin blood flow in response to applied pressure decreased early in diabetic patients as a result of vascular and/or neural impairment. This study was designed to determine the effect of vascular changes ...
Agarwal R - - 2004
BACKGROUND: Oxidative stress is implicated in the pathogenesis of chronic kidney disease (CKD) and essential hypertension (EHTN). However, the role of hypertension in causing increased oxidative stress in patients with CKD is unknown. METHODS: We performed a case control study in patients with EHTN and those with equal blood pressure ...
Engler Mary B - - 2004
BACKGROUND: Dark chocolate derived from the plant (Theobroma cacao) is a rich source of flavonoids. Cardioprotective effects including antioxidant properties, inhibition of platelet activity, and activation of endothelial nitric oxide synthase have been ascribed to the cocoa flavonoids. OBJECTIVE: To investigate the effects of flavonoid-rich dark chocolate on endothelial function, ...
Siobal Mark - - 2004
Two prostacyclins (prostaglandin E(1) and prostaglandin I(2)) are potent vasodilators. Aerosolized prostacyclins reduce pulmonary artery pressure, improve right heart function, and increase arterial oxygenation by improving ventilation/perfusion matching. This report describes aerosolized prostacyclins and compares them to inhaled nitric oxide. I review the types of inhalable prostacyclins and their indications, ...
Peluso Ilaria - - 2004
Convincing evidence suggests that blood redox changes play a role in the development of various cardiovascular disorders including hypertension. Nutritional antioxidants have been suggested to play a role in cardiovascular disease prevention. In this study, we investigated in vivo changes in rat arterial blood pressure induced by acute exposition to ...
Kao Shang Jyh - - 2004
Pulmonary edema (PE) may occur with enterovirus 71 (EV71) infection. We monitored arterial pressure (AP) and heart rate (HR) in patients with EV71 infection and analyzed the variability of AP and HR. Sympathetic activity, AP, and HR increased with respiratory stress. Thereafter, parasympathetic activity increased with decreases in AP and ...
Zhang Zhong - - 2004
We tested whether luminal perfusion and pressurization induce an endothelial cytoplasmic Ca(2+) ([Ca(2+)](CYT)) response in descending vasa recta (DVR). DVR isolated from the rat outer medulla were cannulated and subjected to free-flow microperfusion (5 nl/min); the onset of which increased [Ca(2+)](CYT) from a baseline of 76 +/- 13 to 221 ...
Nakamura Takayuki - - 2004
BACKGROUND: Vasoconstriction in pulmonary ischemia-reperfusion injury may involve dysfunction of the physiologic vasodilation of pulmonary arteries. Little is known of the relative importance of heme oxygenase (HO)/carbon monoxide (CO)-dependent vs nitric oxide synthase (NOS)/nitric oxide (NO)-dependent vasodilation of the pulmonary vasculature. We evaluated the significance of HO function on basal ...
Fernández Nuria - - 2004
Coronary reactivity to endothelin-1 and vasopressin during acute, moderate hypertension, and the role of nitric oxide (NO) and prostanoids in this reactivity was examined in anesthetized goats. Left circumflex coronary flow was electromagnetically measured, and hypertension was induced by constriction of the thoracic aorta in animals nontreated (7 goats) or ...
Palloshi Altin - - 2004
Thirteen hypertensive patients with microvascular angina were studied before and after receiving oral L-arginine (4 weeks, 2 g, 3 times daily). L-arginine significantly improved angina class, systolic blood pressure at rest, and quality of life. Maximal forearm blood flow, plasma L-arginine, L-arginine:asymmetric dimethyl arginine ratio, and cyclic guanylate monophosphate increased ...
Stokes Gordon S - - 2004
In elderly patients with systolic hypertension resistant to treatment with conventional therapy, increased aortic pulse wave reflection and a high augmentation index are often present. These findings are indicative of endothelial dysfunction and deficient generation of nitric oxide, a potent vasodilator in the arterial tree. In such patients, treatment with ...
Brown Russell - - 2004
BACKGROUND: In the kidney the neuronal isoform of nitric oxide synthase (nNOS) is located in the macula densa cells. These cells are known to be the sensor in the tubuloglomerular feedback. During volume expansion (VE), the tubuloglomerular feedback response is attenuated, allowing increased water and salt excretion. This study addressed ...
Molinari C - - 2004
Dehydroepiandrosterone has been implicated in vascular disease and its associated insulin resistance and hypertension, though little is known about its vascular effects. We have recently shown in prepubertal anaesthetized pigs that intravenous infusion of dehydroepiandrosterone caused coronary vasoconstriction through the inhibition of a vasodilatory beta-adrenergic receptor-mediated effect related to the ...
Koïtka Audrey - - 2004
Vascular and neurological mechanisms are both likely to be involved in foot ulcer. We recently reported a pressure-induced vasodilation (PIV), relying on unmyelinated afferent excitation. We previously found that cutaneous blood flow in response to locally applied pressure might be impaired in diabetic patients because of the combined effects of ...
Piccirillo Gianfranco - - 2004
In this study, we used spectral analysis to assess changes in respiratory recording variability during infusion of L-arginine and vitamin C, individually or together, in patients with chronic heart failure. We found that healthy subjects have a substantial ability to modulate sympathetic-mediated peripheral vascular resistance through endothelial synthesis of nitric ...
Yang Qin - - 2004
BACKGROUND: The University of Wisconsin (UW) solution is used widely in heart preservation but has been demonstrated to be detrimental to the endothelial function. The present study compares the effect of histidine-tryptophan-ketoglutarate (HTK) and UW solutions on endothelium-derived hyperpolarizing factor (EDHF)-mediated function in porcine small coronary arteries. METHODS: An isometric ...
Keller Roberta L RL Cardiovascular Research Institute and the Department of Pediatrics, The University of California San Francisco, San Francisco, CA, - - 2004
We describe a case of chronic pulmonary hypertension in a 7-wk-old infant with congenital diaphragmatic hernia and an oral teratoma. Our patient was dependent on low-dose inhaled nitric oxide and was still very unstable with systemic right ventricular pressures leading to frequent oxygen desaturations. We administered sildenafil therapy to stabilize ...
Talman William T - - 2004
Because inhibition of neuronal nitric oxide synthase in the nucleus tractus solitarii blocks cardiovascular responses to activation of local glutamate receptors, and because glutamate is a neurotransmitter of baroreceptor afferent nerves, we sought to test the hypothesis that neuronal nitric oxide synthase inhibition would block baroreflex transmission and cause hypertension. ...
Alexander Barbara T - - 2004
A chronic reduction in uterine perfusion pressure in the pregnant rat is associated with significant elevations in mean arterial pressure, proteinuria, and reductions in kidney function as is chronic nitric oxide blockade, suggesting that nitric oxide deficiency may contribute to the clinical manifestations of preeclampsia. The purpose of this study ...
Fujioka Hideyuki - - 2004
The isolated rat mesenteric vasculature was perfused at constant pressures of 40, 80 or 120 mm Hg and the change in flow rate was measured. In the presence of phenylephrine, treatment with 3-[(3-cholamidopropyl) dimethylammonio]-1-propane sulfonate (CHAPS) or N(G)-nitro-L-arginine (L-NA) significantly inhibited the pressure-dependent flow rate increase, but treatment with indomethacin ...
Sandow Shaun L - - 2004
A role for myoendothelial gap junctions (MEGJs) has been proposed in the action of the vasodilator endothelium-derived hyperpolarizing factor (EDHF). EDHF activity varies in disease and during ageing, but little is known of the role of EDHF during development when, in many organ systems, gap junctions are up-regulated. The aims ...
Sun Y - - 2004
AIM: Experiments were performed in anaesthetized rats to clarify the role of nitric oxide (NO) in the control of colonic permeability. METHODS: Colonic luminal pressure, the transmucosal potential difference (PD) and the clearance of [3H] mannitol and [14C] urea from blood to lumen were measured. NO synthesis was blocked with ...
Zhao J L - - 2004
This study examined whether nitric oxide (NO) is involved in the cutaneous response to reactive hyperemia (RH) in the human forearm. We enrolled seven healthy volunteers. NO concentrations were monitored using a NO selective amperometric electrode (ISO-NOP200, World Precision Instruments) inserted into the skin of the forearm. Laser-Doppler flowmetry (Moor ...
Ryan Michael J - - 2004
The peroxisome proliferator activated receptor (PPARgamma) agonist rosiglitazone has been reported to yield cardiovascular benefits in patients by a mechanism that is not completely understood. We tested whether oral rosiglitazone (25 mg/kg per day, 21 days) treatment improves blood pressure and vascular function in a transgenic mouse expressing both human ...
Soop A - - 2004
BACKGROUND: Endotoxin is a major stimulus for triggering the host response in septicaemia. The pathophysiology of sepsis involves activation of the vascular endothelium and leukocytes, resulting in the release of various mediators, e.g. cytokines, nitric oxide (NO), endothelin (ET-1) and complement factors. We evaluated the blood levels of complement activation, ...
von der Thüsen Jan H - - 2004
OBJECTIVE: Restenosis remains a major late complication of percutaneous transluminal coronary angioplasty (PTCA), for which the development of prevention strategies has thus far been hampered by the lack of a representative and practical animal model. We have, therefore, developed a murine model of PTCA-induced restenosis. METHODS AND RESULTS: Rigid probe ...
Kondo Ryoichi - - 2003
The measurements of exhaled nitric oxide (ENO) concentrations in several previous reports have been quite disparate but the cause of this variability is unclear. In the present study, we have attempted to elucidate the effects of expiratory pressure upon ENO values by taking measurements at pressures ranging from 2 to ...
Neufeld Arthur H - - 2003
The loss of vision in the human eye disease, glaucoma, is due to degeneration of the axons of the retinal ganglion cells. In glaucoma, reactive astrocytes in the optic nerve head contain inducible nitric oxide synthase, which apparently produces excessive nitric oxide that damages the axons. The astrocytes respond to ...
Dayoub Hayan - - 2003
BACKGROUND: NO is a major regulator of cardiovascular physiology that reduces vascular and cardiac contractility. Accumulating evidence indicates that endogenous inhibitors may regulate NOS. The NOS inhibitors asymmetric dimethylarginine (ADMA) and N-monomethylarginine are metabolized by the enzyme dimethylarginine dimethylaminohydrolase (DDAH). This study was designed to determine if increased expression of ...
Foubert Luc - - 2003
Continuous administration of inhaled nitric oxide is now widely used as a potent and selective pulmonary vasodilator. We have evaluated the effects of IV dipyridamole, a cyclic guanosine monophosphate (cGMP) phosphodiesterase inhibitor, on the magnitude and duration of action of inhaled nitric oxide (NO)-mediated pulmonary vasodilation. We hypothesized that inhibition ...
Ogasawara Hitoshi - - 2003
It has been suggested that overproduction of nitric oxide (NO) by nitric oxide synthase (NOS) contributes to blunted hypoxic pulmonary vasoconstriction (HPV) during endotoxemia. We investigated the effect of a selective inducible NOS (iNOS) inhibitor, ONO-1714, on the loss of HPV during endotoxemia in awake sheep to clarify the role ...
Middelveld R J M - - 2003
AIM: This study was carried out to study the prophylactic effects of inhalation of nitric oxide (NO) before and during the induction of endotoxic shock. METHODS: Eighteen anaesthetized pigs received an infusion of 10-20 microg kg(-1) endotoxin during 2 h after pre-treatment with the cortisol-synthesis inhibitor metyrapone. Three groups were ...
Terrand J - - 2003
Nitric oxide synthase (NOS) is strongly and transiently expressed in the developing heart but its function is not well documented. This work examined the role, either protective or detrimental, that endogenous and exogenous NO could play in the functioning of the embryonic heart submitted to hypoxia and reoxygenation. Spontaneously beating ...
Ramchandra Rohit - - 2003
Although the vascular action of endothelium-derived nitric oxide in modulating arterial pressure is well established, nitric oxide can also act as a neurotransmitter in the central nervous system. In addition, there is evidence for an interaction between nitric oxide and baroreceptor afferent processing; thus, nitric oxide may regulate blood pressure ...
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