Search Results
Results 401 - 450 of 999
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Pönicke K - - 2000
The aim of this study was to characterize the receptor subtype involved in cardiac effects of prostanoids. For this purpose we determined in neonatal and adult rat cardiomyocytes effects of prostanoids on inositol phosphate (InsP)-formation (assessed as accumulation of total [(3)H]-InsP's in myo-[(3)H]-inositol pre-labelled cells) and on rate of protein ...
Nevière R - - 2000
OBJECTIVE: to determine whether inhaled nitric oxide (NO) would alter leukocyte kinetics in the septic microvasculature. DESIGN: Randomized, controlled trial. SETTING: Experimental laboratory. SUBJECTS: Male Sprague Dawley rats. INTERVENTIONS: Rats were treated with either saline or endotoxin (10 mg/kg, iv) and then allowed to breathe either air or air plus ...
Zhou L - - 2000
OBJECTIVE: To investigate the vasoactive effects of adrenotensin and the interactions between adrenotensin and adrenomedullin (ADM). METHODS: Isolated rat aortic tension, rat mean arterial pressure and 3H-TdR incorporation of rat vascular smooth muscle cells were measured. Isolated rat aortas were incubated in K-H solution containing adrenomedullin or adrenotensin. The released ...
Damaser M S - - 2000
OBJECTIVE: To compare directly the biochemistry and contractile responses of rat and rabbit bladder to different stimuli. Materials and methods Sexually mature male New Zealand White rabbits and Sprague Dawley rats were compared. Each bladder was excised while the animal was anaesthetized; longitudinal bladder strips were cut and then mounted ...
Kagota S - - 2000
We examined endothelium-dependent relaxation in the aortas and renal arteries of Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a model of non-insulin-dependent diabetes mellitus, in comparison with non-diabetic Long-Evans Tokushima Otsuka rats as controls. Acetylcholine-induced relaxation in both arteries was attenuated, and the attenuation was restored to the control level by ...
Lecci A - - 2000
The application of nociceptin (5-50 nmol/rat) onto the serosa in the urinary bladder of urethane-anaesthetized rats, with the intravesical volume kept below threshold for activation of the micturition reflex, induced a low amplitude tonic contraction (local, i.e., resistant to ganglionectomy) with high amplitude phasic contractions (reflex, i.e., abolished by ganglionectomy) ...
Davidson-Garcia C A - - 2000
We reported previously that acetylcholine (ACh)-induced endothelium-dependent relaxation of rat mesenteric microvessels depended both on nitric oxide (NO) and on a charybdotoxin (CTX)-sensitive endothelium-derived hyperpolarizing vasodilator. Cytochrome P450 (CYP)-dependent arachidonic acid metabolites act in some systems as hyperpolarizing vasodilators. We sought to quantitate contributions of such metabolites to the CTX-sensitive ...
Kim H W - - 2000
The origin and mechanism of vasocontraction observed after vascular exposure to acellular Hbs remain controversial. To help resolve the underlying mechanism, we characterized Hb-induced vasoactivities in terms of Hb purity, heme iron oxidation state, and ligand and pharmacodynamic properties. Isolated rat thoracic aortic rings with intact endothelium were suspended in ...
Sangha D S - - 2000
Simulated microgravity depresses the ability of arteries to constrict to norepinephrine (NE). In the present study the role of nitric oxide-dependent mechanisms on the vascular hyporesponsiveness to NE was investigated in peripheral arteries of the rat after 20 days of hindlimb unweighting (HU). Blood vessels from control rats and rats ...
Katakam P V - - 2000
This study assessed the effect of metformin treatment on insulin, mean arterial pressure (MAP), and endothelial function in insulin-resistant (IR) rats. In addition, we assessed the direct effect of metformin in vitro. Sprague-Dawley rats were randomized to control (n=28) or IR (n=28) groups. Rats were further randomized to receive metformin ...
Scalia R - - 2000
A novel synthetic phosphorothioate analog of oleoyl lysophosphatidic acid LXR-1035 was studied for its ability to modulate leukocyte-endothelial cell interactions using intravital microscopy of the rat mesentery. Superfusion of the rat mesentery with 50 microM L-NAME elicited a significant, time-dependent increase in leukocyte rolling, adherence, and transmigration compared to control ...
Kano Y - - 2000
The purpose of the present study was to examine the effects of age on vascular responses to acetylcholine (ACh) and NO-releasing compound (NOC-18). The studies were performed in young (4 months old, n = 8) and old (22 months old, n = 6) male rats. Responses to ACh and NOC-18 ...
Abebe W - - 2000
The effects of chronic taurine treatment on the reactivity of the aorta form male Wistar-Kyoto rats were investigated. Contractile responses to norepinephrine (NE) and potassium chloride (KCl) were attenuated in aortic rings from taurine-treated rats as compared to controls both in the absence and presence of endothelium. However, the degree ...
Kim S H - - 2000
The extract of Crataegus, a mixture of flavonoids and procyanidins extracted from hawthorn, Crataegus oxyacantha, L. and C. monogyna Jacq., relaxed vascular tone or increased production of cyclic GMP in the rat aorta, but flavonoid components of Crataegus extract, hyperoside, rutin and vitexin, did not affect the vascular tone. The ...
Zhou X - - 2000
To evaluate the possibility of employing ligustrazine in the prevention of restenosis, the effects of ligustrazine on the intimal thickening of air-injured carotid artery of rats were investigated, and the effects of ligustrazine on the proliferation of rabbit aortic median smooth muscle cells (SMCs) cultivated in vitro were examined. Artery ...
Jeon B H - - 2000
The effect of high blood flow on the expression of endothelial nitric oxide synthase has been investigated in the femoral arteriovenous shunt (AVS) rats created by inserting U-shaped polyurethane tubes in the left femoral arteries and veins. Three days after inserting the femoral AVS, the mean aortic blood flow rate ...
Shinozaki K - - 1999
To investigate underlying mechanisms responsible for the impaired nitric oxide (NO)-dependent vascular relaxation in the insulin-resistant state, we examined production of both NO and superoxide anion radical (O2-) and those modulating factors in aortas obtained from normal (CTR), insulin-treated (INS), or high fructose-fed (FR) rats. FR rats showed insulin resistance ...
Mori K - - 1999
BACKGROUND: Colforsin, a novel water-soluble forskolin derivative, increases intracellular cyclic AMP by direct stimulation of adenylate cyclase and has strong positive inotropic and vasodilative effects. However, it is not known whether colforsin causes nitric oxide (NO) release and enhances endothelium-dependent vascular relaxation. METHODS: We studied NO production and relaxation on ...
Calderone V - - 1999
Artemisia verlotorum Lamotte (Compositae), growing in almost all the northern hemisphere, is used in folk medicine of some countries of Tuscany, Italy, as a remedy for hypertension. The pharmacological evaluation of the responses evoked by an aqueous dried extract of Artemisia verlotorum on the blood pressure of anaesthetized rats and ...
Nakazawa H - - 1999
1. It has been reported that endothelium-dependent relaxation is impaired in pulmonary hypertensive vessels. The underlying mechanisms for this phenomenon, however, have not yet been identified. In this study, the mechanisms responsible for decreased endothelium-dependent relaxation in the pulmonary artery isolated from monocrotaline (MCT)-induced pulmonary hypertensive rat (MCT rat) were ...
Wang D - - 1999
Hypertension and vascular disease are common complications in autosomal-dominant polycystic kidney disease (ADPKD). The role of changes in morphology and reactivity of resistance vessels in this disease have not previously been studied. Mesenteric resistance arteries were dissected from 8- to 14-week-old heterozygous Han:SPRD polycystic kidney disease (PKD) rats, homozygous normal ...
Coats P - - 1999
The effects of longitudinal stretch on vasoreactivity were assessed in isolated, pressurised arteries from the rat mesentery, rat mid-cerebral and human subcutaneous vascular beds. A stretch-dependent increase in reactivity was observed only in rat third order mesenteric arteries. Longitudinal stretch >> 20 % (force equal to 0.23 +/- 0.04 mN) ...
Dantas M F - - 1999
We have tested the hypothesis that increased gap junctional communication contributes to the augmented endothelium-dependent vasodilation in pregnancy. Contractile force and connexin43 expression were measured in aortic rings from nonpregnant and pregnant rats. Norepinephrine-constricted aortas from pregnant rats were more sensitive to acetylcholine, but not to sodium nitroprusside, compared with ...
Sauvage M - - 1999
The elastin content in the thoracic aorta of male Brown-Norway (BN) rats is 31.4+/-1.2% (dry weight), whereas that of male LOU rats is 37.2+/-1.0%. A similar difference in the elastin content of the thoracic aorta is also observed in female animals. Furthermore, in the thoracic aorta of young, growing rats ...
Chamiot-Clerc P - - 1999
OBJECTIVE: We have previously shown that conduit arteries of normotensive (WKY) and hypertensive (SHR) Japanese rats differ from normotensive (LN) and hypertensive (LH) Lyon rats in terms of lower aortic thickness and higher collagen III content, whereas differences in vasoactive properties are unknown. METHODS: Aortic rings with (E+) and without ...
Browne M - - 1999
1. It has been proposed that the cardiovascular protective actions of 17beta-oestradiol may involve calcium antagonistic actions. We have examined the effects of 17beta-oestradiol on contractions to noradrenaline and KCl in male rat small mesenteric artery and aorta. 2. In rat mesenteric artery, 17beta-oestradiol (10 microM) significantly reduced the maximum ...
Takiuti N H - - 1999
CONTEXT: The exact mechanism involved in changes in blood pressure and peripheral vascular resistance during pregnancy is unknown. OBJECTIVE:To evaluate the importance of endothelium-derived relaxing factor (EDRF) and its main component, nitric oxide, in blood pressure and vascular reactivity in pregnant rats. DESIGN: Clinical trial in experimentation animals. SETTING: University ...
Kashiwagi A - - 1999
Impairment of nitric oxide-dependent vascular relaxation is a characteristic feature of the insulin-resistant state. To understand those mechanisms, we examined imbalance of O2-/NO production in aortic endothelial cells obtained from high fructose-fed, exogenous hyperinsulinemic, and control rats. Aortic segments from both high fructose-fed and insulin-treated rats produced a 4-fold more ...
Tsai H Y - - 1999
The interactions and mechanisms between veratrine and paeoniflorin on the isolated rat aorta were studied. Veratrine (1x10(-6) to 1x10(-4) g/ml) could induce contraction on the isolated rat aorta in a concentration-related manner. Paeoniflorin had no effect on the isolated rat aorta. Pretreatment with prazosin (1x10(-6) M) and nifedipine (1x10(-6) M) ...
Ceiler D L - - 1999
OBJECTIVES: The contribution of vascular changes to the development of heart failure is largely unknown. In the present study, we evaluated endothelial and vascular contractile function in the rat hindlimb vascular bed after myocardial infarction (MI), including the modulatory role of basal nitric oxide (NO) production and the effects of ...
Yang Z W - - 1999
The effects of extracellular Mg2+ ion ([Mg2+]0) deficiency on basal tension of isolated rat aortae and rat aortic smooth muscle cell Ca2+ metabolism were investigated in the present study. The contractions of rat aortae induced by diverse concentrations of low [Mg2+]0 were potentiated, greatly, by removal of the endothelium or ...
Horinouchi T - - 1999
We previously suggested that the existence of atypical beta/beta3-adrenoceptor with pA2-values for bupranolol, a non-selective beta-adrenoceptor antagonist, against BRL37344 and noradrenaline were 5.79 and 5.53 in guinea pig taenia caecum, respectively. We furthermore determined the affinity of bupranolol to subclassify atypical beta/beta3-adrenoceptor in rat oesophageal muscularis mucosae, because it is ...
Eltze M - - 1999
The affinity for functional alpha1-adrenoceptor subtypes of buspirone in comparison with its close structural analogs and selective alpha1D-adrenoceptor antagonists, BMY 7378 (8-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-8-azaspiro[4.5]dec ane-7,9-dione) and MDL 73005EF (8-[2-(1,4-benzodioxan-2-ylmethylamino)ethyl]-8-azaspiro+ ++[4.5]decane-7,9-dione), was determined, namely at subtype A in rat vas deferens and perfused kidney, at subtype B in guinea-pig and mouse spleen, at ...
Malmsjö M - - 1999
OBJECTIVE: Congestive heart failure (CHF) is accompanied by enhanced peripheral sympathetic nerve activity, increased vascular resistance and impaired peripheral blood flow. Besides noradrenaline and neuropeptide Y, the sympathetic nervous system also releases ATP, which has contractile effects mediated by different subtypes of P2-receptors on the vascular smooth muscle cells. The ...
Zhou M S - - 1999
The present study is designed to investigate whether acetylcholine (ACh) elicits an endothelium-derived contracting factor (EDCF) and whether it contributes to decreased relaxant response induced by ACh in Dahl rats. Dahl salt-sensitive (DS) and -resistant (DR) rats were fed a 0.4% NaCl or an 8% NaCl diet for 4 weeks. ...
De la Lande I S - - 1999
Mechanisms of mild glyceryl trinitrate tolerance in rats (transdermal application; 15 mg/day/2 days) were examined in isolated aortic rings contracted with phenylephrine. Tolerance to glyceryl trinitrate was comparable in both endothelium-intact and -denuded vessels; the maximum relaxation decreased to 70-80% and the EC50 increased 3-4-fold. There was minimal cross-tolerance to ...
Kusterer K - - 1999
OBJECTIVE/METHODS: In order to investigate whether selective hypertriglyceridemia impairs endothelium-dependent vasodilatation in the rat hindlimb, rats were selectively bred to establish two strains, one with a pronounced hypertriglyceridemia (HT) and the other with normal plasma levels of triglycerides (LT). RESULTS: Carotid arteries and aortae removed from 3, 6, 9 and ...
Saïag B - - 1999
This study investigates the effects of agents which act on the production or efficacy of free radicals on the hypoxic responses of rat aorta rings. Under moderate hypoxic conditions, the resting tension of the rings was not changed but in rings precontracted with 5-hydroxytryptamine, there was a relaxation followed by ...
Mirkhani H - - 1999
Mebudipine and dibudipine are two new dihydropyridine calcium-channel blockers that have been synthesized in our laboratory. In a previous study, they showed considerable relaxant effect on vascular and ileal smooth muscle. Here, the pharmacological effects of mebudipine and dibudipine on isolated rat left atrium, rat blood pressure and isolated human ...
Doolen S - - 1999
The purpose of this study was to determine whether estrogen modulates the function of vascular melatonin receptors. We used the rat caudal artery and found that the contractile effects of melatonin were influenced by the estrous cycle, ovariectomy, and estrogen replacement. In arterial ring segments isolated from female rats, melatonin ...
Gaine S P - - 1999
Septic shock induced by lipopolysaccharide (LPS) produces systemic hypotension and decreased responsiveness to vasoconstrictors. Recently, intravenous injection of hemoglobin (HGB) into rats was found to be protective from a subsequent lethal dose of LPS and was correlated with induction of the enzyme heme oxygenase-1 (HO-1). To determine whether the HGB ...
Florian J A - - 1999
We have tested the hypothesis that growth factor signaling pathways are augmented in hypertension, a disease associated with vascular smooth muscle cell growth. Thoracic aorta was dissected from deoxycorticosterone acetate-salt (DOCA-salt) and one kidney, one clip (1K, 1C) hypertensive rats and from sham normotensive rats for use in isolated tissue ...
Zhang C Y - - 1999
14-deoxyandrographolide (DA) and 14-deoxy-11,12-didehydroandrographolide (DDA) are two diterpenoids isolated from A. paniculata, a popular folk medicine used as an antihypertensive drug in Malaysia. We have previously reported that DDA exhibited a greater hypotensive effect in anaesthetized rats and a vasorelaxant activity in isolated rat aorta, compared with DA. Their vasorelaxant ...
Takahashi T - - 1999
This study was designed to investigate the mechanism(s) and the site(s) of action of cholecystokinin (CCK) responsible for the smooth muscle relaxation of the rat stomach. Under xylazine and ketamine anesthesia, an extraluminal force transducer was implanted on the serosal surface of the gastric body to monitor the circular muscle ...
Battarbee H D - - 1999
Decreased cardiac contractility and beta-adrenergic responses have been observed in the chronic portal vein-stenosed (PVS) rat. Because nitric oxide (NO) may be increased in PVS and has been recognized as a negative inotropic agent, we investigated the induction of NO synthase (NOS2) and/or changes in constitutive NOS (NOS3) as factors ...
Illanes A G - - 1999
In 1993, Illanes et al. described a vasoactive factor, the auricular vasorelaxing factor (AVF), by controlled distension of rat isolated atria. This factor produces vasodilation, antagonizing the vasoconstrictor action of phenylephrine. We now report assays by using isolated rat aortic rings and norepinephrine as a vasoconstrictor. Isolated thoraxic aortic rings ...
Fujimura T - - 1999
PURPOSE: To investigate the presence of the beta3-adrenoceptor (beta3-AR) in human and rat detrusor muscle and the usefulness of beta3-AR agonists as drugs for the treatment of urinary frequency. MATERIALS AND METHODS: FK175, ethyl [(S)-8-[(R)-2-(3-chlorophenyl)-2-hydroxyethylamino]-6,7,8,9-tetrah ydro-5H-benzocyclohepton-2-yloxy]acetate monohydrochloride monohydrate, was used as a beta3-AR selective agonist. The expression of beta-AR subtypes ...
Holland H L - - 1999
PURPOSE: The syntheses and evaluation for cardiovascular activity in the rat of both enantiomers of a verapamil analog in which the cyano group has been replaced by hydroxyl. METHODS: (+)- and (-)-alpha-[3-[[2-(3,4-Dimethoxyphenyl)ethyl]methylamino]propyl]- 3,4-dimethoxy-alpha-(1-methyl ethyl)benzyl alcohol were prepared from chiral sulfoxides produced by microbial biotransformations using Mortierella isabellina ATCC 42613 or ...
Delgado J L - - 1999
1. Experiments were performed to examine and to compare vascular endothelial function in aortic rings from oophorectomized and from ovary-intact rats and to test the effect of thiol compound as N-acetylcysteine on endothelial function. 2. In precontracted aortic rings from oophorectomized and intact rats, vascular endothelial function was evaluated by ...
Bigatel D A - - 1999
Matrix metalloproteinases (MMPs) are proteolytic enzymes that can degrade the extracellular matrix of the aortic wall and lead to the formation of abdominal aortic aneurysms (AAAs). MMP inhibitors are a class of drugs that were developed to inhibit the activity of these proteolytic enzymes and are currently being studied as ...
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