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Results 351 - 400 of 1023
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Török Jozef - - 2002
The present study examined whether pentaerythrityl tetranitrate (PETN), a tolerance-devoid exogenous donor of nitric oxide (NO), could attenuate functional and morphological changes in the rat thoracic aorta evoked by 6-week NO synthase inhibition by NG-nitro-L-arginine methyl ester (L-NAME). Systolic blood pressure in L-NAME + PETN-treated rats (163 +/- 1 mm ...
Ismailoglu U B - - 2002
The protective effect of phenylpropanoid glycosides, forsythoside B and alyssonoside, and the iridoid glycoside lamiide, isolated from the aerial parts of Phlomis pungens var. pungens, against free radical-induced impairment of endothelium-dependent relaxation in isolated rat aorta was investigated. Aortic rings were exposed to free radicals by the electrolysis of the ...
Gonzales Rayna J - - 2002
Chronic hypoxia (CH) is associated with a persistent reduction in systemic vasoconstrictor reactivity. Experiments on aortic ring segments isolated from CH rats suggest that enhanced vascular expression of heme oxygenase (HO) and resultant production of the vasodilator carbon monoxide (CO) may underlie this attenuated vasoreactivity after hypoxia. Similar to the ...
Northcott C - - 2001
Epidermal growth factor (EGF) causes contraction in arteries from deoxycorticosterone acetate (DOCA)-salt hypertensive rats but not in normotensive sham rats. We hypothesized that an increase in the number of EGF receptors (EGFRs) in arteries from DOCA-salt rats enables the observed contraction to EGF to occur. DOCA-salt rats had a systolic ...
Kurahashi K - - 2001
Nicotine caused a contraction of the rat coronary artery in the presence of Nomega-nitro-L-arginine methyl ester (L-NAME) and arachidonic acid, and did not in the absence of these agents. The present experiments were undertaken to pharmacologically characterize the nicotine-induced contraction in ring preparations of the rat coronary artery. The contraction ...
Mendizábal V E - - 2001
In rat isolated mesenteric beds, anandamide induced a concentration-dependent reduction (0.01-50 microM) of the contractile responses elicited by bolus administration of noradrenaline. The anandamide-induced reductions of noradrenaline responses were unmodified by the in vitro exposure to the nitric oxide synthase (NOS) inhibitor, 100 microM L-N(G)-nitro-L-arginine methyl ester (L-NAME), whereas they ...
Yamaguchi K - - 2001
The mode of action of estrogen on beta-adrenoceptor-mediated relaxation was investigated by using isolated ring preparations of thoracic aorta from ovariectomized rats. Administration of 17beta-estradiol to ovariectomized rats significantly suppressed isoprenaline-induced relaxation of aortic rings. There was no alteration in the beta-adrenoceptor binding characteristics. The suppressing action of 17beta-estradiol on ...
Gurib F B - - 2001
Possible pharmacological effects of N-alpha-tosyl L-arginine methyl ester [TAME] were studied on rat aorta strips in vitro. Results showed that [TAME]-esterase was an endothelium dependent component that involved a nitric oxide cyclic-GMP mediated pathway. Furthermore, during activation of Kinin-Kallikrein system, TAME-esterase induced contractions involve degradation of kinins by kininases.
Barron L A - - 2001
High-salt (HS) diet is often associated with increased vascular resistance and arterial pressure; however, the effects of HS intake on the vascular control mechanisms of arterial pressure during pregnancy are unclear. We investigated whether a HS diet during pregnancy is associated with increases in vascular reactivity. Active stress was measured ...
Sadraei H - - 2001
Traditional herbal medicines such as Ferula gummosa Boiss. have been used for treatment of intestinal disorders in Iran. To date no pharmacological evidence for their effectiveness has been reported. The aim of this study was to examine the relaxant effect of essential oil, hydro-alcoholic, etheric, petrolic and methanolic extracts of ...
Woods M - - 2001
Recent evidence indicates that in a number of species detrusor relaxation is mediated through activation of the beta3-adrenergic receptor. We determined whether activation of the beta3-adrenergic receptor would be a useful therapeutic approach for bladder instability. We profiled in vitro activity of the beta3-adrenergic receptor agonist CL-616243 and the efficacy ...
Chan H Y - - 2001
The present study was aimed to examine the different role of endothelium/nitric oxide in relaxation induced by two female sex hormones, 17beta-estradiol and progesterone in rat isolated aortas and mesenteric arteries. The isometric force of each ring was measured with Grass force-displacement transducers in the organ bathes. 17beta-Estradiol induced both ...
Whiteley P E - - 2001
Injection of adjuvant (Mycobacterium butyricum suspended in mineral oil) into rats produces an immune reaction that characteristically involves inflammatory destruction of cartilage and bone of the distal joints with concomitant swelling of surrounding tissues. Adjuvant-induced arthritis in rats is commonly used to evaluate compounds that might be of potential use ...
Wang Y - - 2001
Trout endothelin (ET), previously isolated from the kidney of the rainbow trout Oncorhynchus mykiss, contains four amino acid substitutions at residues 4-7 compared with rat ET-1. Trout ET produced sustained and concentration-dependent contractions of strips of longitudinal smooth muscle from trout stomach (pD(2) = 7.52 +/- 0.06) and proximal small ...
Veale D J - - 2001
This study on the rat myometrium is the first report where the effects of herbal extracts used as oxytocics in traditional medicine have been systematically analysed in the same preparation at the level of functional (contractile) and biochemical (second messenger generation) responses. Extracts of Agapanthus africanus and Clivia miniata (used ...
Straumann D - - 2001
We have studied the effects of a St. John's wort extract used in therapy on contractions of various isolated organ preparations induced by diverse spasmogens. Although it nonspecifically antagonized guinea pig ileum contractions induced by 7 different spasmogens, it had no effect on depolarization-induced contractions of rat aorta or those ...
Yarar Y - - 2001
OBJECTIVE: We compared in vitro relaxant effect of chloride channel modulators, such as 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB) and anthracene-9-carboxylate (9-AC), and beta(2)-adrenergic agonists, such as ritodrine, in pregnant rat myometrium. METHODS: Isolated myometrial strips were obtained from eight pregnant rats, and the strips were mounted in organ baths for recording ...
Witte K - - 2001
TGR(mREN2)27 (TGR) rats develop severe hypertension and an inverted circadian blood pressure profile with peak blood pressure in the day-time rest phase. The present study investigated the in vitro responsiveness of different arteries of TGR rats during day and night. Twelve-week-old TGR rats and normotensive Sprague-Dawley (SPRD) controls, synchronized to ...
Ulker S - - 2001
OBJECTIVE: Aprotinin, a non-specific serine protease inhibitor, reduces postoperative bleeding after coronary artery surgery. The mechanism of action for this 'blood-sparing' effect of aprotinin is only partially clarified. We therefore aimed to investigate the effect of aprotinin on the release of nitric oxide (NO), a vasodilator and antiaggregant factor, from ...
Karamsetty M R - - 2001
Phytoestrogens derived from soybeans reverse endothelial dysfunction in a number of animal models of systemic vascular disease. Based on these studies, we hypothesized that phytoestrogens would reverse chronic hypoxia-induced endothelial dysfunction in rat pulmonary arteries. To test this hypothesis we examined the effect of genistein, the major phytoestrogen found in ...
Zhang L N - - 2001
Recently, hypertrophy and increased myogenic tone of brain vessels have been observed in rats after simulated microgravity. It is expected that simulated microgravity may also induce hyperreactivity of brain vessels. To test this hypothesis, Sprague-Dawley rats were subjected to a 4-wk tail-suspended hindlimb unloading (TS) to simulate the cardiovascular deconditioning ...
Chin-Dusting J P - - 2001
Legume-derived isoflavones such as genistein, diadzein and equol have been associated with a reduction in risk of cardiovascular disease. In the current study, we explore the vascular activity of several isoflavone metabolites namely dihydrodaidzein, cis and trans-tetrahydrodaidzein and dehydroequol for potential cardioprotective properties. Rat isolated aortic rings were used. 17beta-oestradiol, ...
Teede H - - 2001
Although gender and oestrogen treatment influence production of the vasorelaxant, NO, their influence on factors downstream in the NO signal-transduction pathway, specifically protein kinase G (PKG), remains unknown. We aimed to study the influence of sex hormones on PKG, along with the endothelial modulation of these effects, in rat thoracic ...
Pessina F - - 2001
The aim of the present investigation was to compare mechanical responses to electrical field stimulation (EFS), as well as cholinergic and non-adrenergic, noncholinergic (NANC) neurotransmission in guinea-pig, rat, monkey and human detrusor muscle strips. Responses to EFS (0.05, 0.5 and 1 ms pulse duration, 50 V, 1-15 Hz) of guinea-pig, ...
Leong S - - 2001
1. We have examined the effects of 17beta-oestradiol on spontaneous spikes and contractions to noradrenaline in rat portal vein. 2. The 17beta-oestradiol (10 microM) significantly reduced the maximum height of spontaneous spike contractions and significantly reduced the maximum contraction to noradrenaline (10 microM) in portal vein from both male and ...
Sekiguchi F - - 2001
Effects of chronic treatment of normotensive Wistar rats with N(omega)-nitro-L-arginine methyl ester (L-NAME) on blood pressure and on endothelium-dependent relaxation of the aorta, carotid and iliac arteries were studied. The endothelium-dependent relaxation was compared in arteries from normotensive Wistar Kyoto rats (WKY) and genetically hypertensive rats (stroke-prone spontaneously hypertensive rats, ...
Vuylsteke A - - 2001
The actions of the blood substitute diaspirin crosslinked hemoglobin (DCLHb) were investigated in rat (small mesenteric artery) and human (radial collateral artery) resistance vessels mounted in a wire myograph for isometric tension recording. DCLHb did not contract resting vessels from rats, but vasoconstrictor responses were observed in isolated arteries and ...
Hennan J K - - 2001
It is generally well accepted that nitrovasodilator-induced relaxation of vascular smooth muscle involves elevation of cGMP and activation of a specific cGMP-dependent protein kinase [protein kinase G (PKG)]. However, the protein targets of PKG and the underlying mechanisms by which this kinase leads to a relaxant response have not been ...
Lacza Z - - 2001
The interaction between uridine-5'-triphosphate (UTP) and prostanoids was studied in isolated rat middle cerebral arteries (MCAs). The strong contractions in MCA segments induced by UTP were weakened significantly by indomethacin and more markedly by the thromboxane receptor antagonist ICI 192605. Thromboxane A(2) (TXA(2)) release by MCAs was below the detection ...
Onoruvwe O - - 2001
The effects of ethanol extracts of Bridelia ferruginea leaves and stem bark on purinergic neurotransmission in the rat bladder were investigated. The stem bark extract potentiated the contraction of the bladder evoked by exogenous adenosine 5-triphosphate (ATP) but depressed KCl-induced contractions in a dose-related pattern; these two opposite actions might ...
Liu M Y - - 2001
This study was undertaken to determine whether endothelium-dependent relaxations are altered in mesenteric arteries from young female rats during oestrus cycle and after castration. The contractile response to phenylephrine (Phe) was significantly enhanced in arteries from rats subjected to ovariectomy than in those from sham-operated (control) rats. Treatment of ovariectomized ...
Yamamoto T - - 2001
Age-dependent changes in the effects of the alpha1-adrenoceptor agonist, phenylephrine were investigated on neurally evoked contractile responses and basal tone in smooth muscle strips from rat urinary bladder. Phenylephrine facilitated the neurogenic contractions in both neonatal and 7-month-old adult rats. However, phenylephrine increased the basal tone in adult but not ...
Emdad L - - 2001
Remodeling of gap-junctional organization in hypertrophied left ventricle (LV) in response to pressure overload in rats induced by abdominal aorta banding was investigated by immunoconfocal and electron microscopy. Eight to 12 weeks after banding, rats developed significant LV hypertrophy. In contrast to control LV myocytes, which showed connexin43 (Cx43) labeling ...
Rosón M I - - 2001
Previous studies from our own laboratory have shown that abdominal aorta rings from two kidney - two clip hypertensive rats (HT) develop hypersensitivity to serotonin (SER) which is related to a decreased nitric oxide (NO) availability and enhanced thromboxane A2 production. In the present study we investigated whether calcium and ...
Satoh M - - 2001
The antagonistic effects of MDL73005EF and tamsulosin and partial agonists clonidine and tizanidine at rat thoracic aorta and rabbit iliac artery alpha1-adrenoceptors were investigated in this study. Selective alpha1-adrenoceptor antagonists MDL73005EF and tamsulosin dose-dependently shifted the concentration-response curves for noradrenaline to the right. Schild plots of the results obtained from ...
Lefilliatre P - - 2001
BACKGROUND AND AIMS: Cirrhosis is associated with a hyperdynamic syndrome and arterial vasodilation that is related to nitric oxide (NO) synthase 3 overactivity. Septic shock is frequently associated with cirrhosis and with a vascular induction of NO synthase 2. The aims of this study were to compare the effects of ...
Tabrizchi R - - 2000
OBJECTIVES: The effects of chloride-free buffer in the absence or presence of the nitric oxide synthase inhibitor, N(omega)-nitro-L-arginine methyl ester (L-NAME), or chloride channel antagonist, indanyloxyacetic acid 94 (IAA-94) on alpha(1)-adrenoceptor mediated contractions were investigated in aortic rings from Dahl salt-resistant normotensive (SRN) and salt-sensitive hypertensive (SSH) rats on a ...
Torres L M - - 2000
A bioassay monitored fractionation of a chloroform extract from the aerial parts of Baccharis trimera yielded a mixture that blocked the Ca2+-induced contractions of KCl- depolarized rat portal vein preparations. Pharmacological tests of two pure compounds isolated from the mixture revealed the dilactonic clerodane diterpene as the active compound.
Vulcu S D - - 2000
The effects of a nitric oxide-donor, S-nitroso-N-acetylpenicillamine, and a direct activator of soluble guanylyl cyclase, 3-(5'-hydroxymethyl-2'-furyl)-1-benzyl indazole (YC-1), on force of contraction (F(c)) and L-type Ca(2+) currents (I(Ca(L))) were investigated in myocardial preparations from neonatal and adult rats. Since hearts from adult and neonatal animals contained 160 and 47 mg/100 ...
Schrage W G - - 2000
The purpose of this study was to test the hypothesis that endothelium-dependent dilation is impaired in soleus resistance arteries from hindlimb-unweighted (HLU) rats. Male Sprague-Dawley rats (300-350 g) were exposed to HLU (n = 14) or weight-bearing control (Con, n = 14) conditions for 14 days. After the 14-day treatment ...
Moreau C - - 2000
Alterations in nitric oxide (NO) and endothelin-1 (ET-1) production have recently been reported in erythropoietin (r-HuEPO)-induced hypertension in renal failure rats. The present study was designed to evaluate the effect of NO synthase inhibition with the L-arginine analog NG-nitro-L-arginine methyl ester (L-NAME) on blood pressure (BP) and ET-1 production in ...
Noris M - - 2000
Conjugated estrogens shorten the prolonged bleeding time in uremic patients and are similarly effective in a rat model of uremia. We have previously demonstrated that the shortening effect of a conjugated estrogen mixture or 17beta-estradiol on bleeding time was abolished by the nitric oxide (NO) precursor L-arginine, suggesting that the ...
Miller A A - - 2000
The aims of this study were to (a) determine whether inducible nitric oxide synthase (iNOS) is expressed in small mesenteric arteries from rats with chronic heart failure (CHF), (b) investigate the functional significance of this potential source of nitric oxide (NO) on vascular responsiveness and (c) investigate the role that ...
Kuo G H - - 2000
Beginning from the screening hit and literature alpha1-adrenergic compounds, a hybridized basic skeleton A was proposed as the pharmacophore for potent and selective alpha1a-AR antagonists. Introduction of a hydroxy group to increase the flexibility afforded B which served as the screening model and resulted in the identification of the second-generation ...
Holemans K - - 2000
Adult offspring of severely diabetic pregnant rats are insulin resistant and display cardiovascular dysfunction. When pregnant they develop mild hyperglycaemia. Diets high in saturated fat have been implicated in the development of cardiovascular disease and vascular dysfunction. In the present study we have determined vascular function in small mesenteric arteries ...
Wangensteen R - - 2000
We examined the role of endothelium-derived relaxing factors nitric oxide (NO), endothelium-derived hyperpolarising factor (EDHF), and prostaglandins (PGs) to P(2Y1)- and P(2Y2)-purinoceptor-induced vasodilation in isolated rat kidney. To do it, we analysed the renal response to ATP, 2-methylthio ATP, and UTP in rat renal vasculature under normal conditions and after ...
Herrera B - - 2000
Temperature may have significant influence on vascular tone in such cases as organ preservation, coronary bypass surgery, and extracorporeal circulation. The aim of this research was to study the direct effect of temperature variation on vascular tone in an attempt to elucidate the mechanisms involved. In a first series of ...
Sametz W - - 2000
We investigated the contracting actions of the isoprostanes (isoPs), 8-iso-prostaglandin (PG) F(2alpha) and 8-iso-PGE(2), in comparison to the effects of the thromboxane (TX) A(2)-mimetic U 46619 and the traditional prostaglandin PGE(2) in the isolated rat aorta, isolated rat gastric fundus and the isolated guinea-pig ileum. U 46619 and 8-iso-PGF(2alpha) caused ...
Varin R - - 2000
BACKGROUND-Chronic heart failure (CHF) impairs the endothelium-dependent, flow-mediated dilation (FMD) of small arteries. However, whether chronic angiotensin-converting enzyme (ACE) inhibition affects the impairment of FMD in CHF is unknown. We investigated the effects of long-term ACE inhibition on the FMD of peripheral arteries in rats with CHF and the mechanism(s) ...
Hajhashemi V - - 2000
Satureja hortensis L. (Lamiaceae) is an annual herb that is used in the traditional medicine of Iran for treating stomach and intestinal disorders. The antispasmodic activity of S. hortensis essential oil (SHEO) was assessed on contractions of isolated ileum, induced by KCl and acetylcholine, and compared with the effect of ...
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