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Results 501 - 550 of 1277
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Molino P - - 1998
A windkessel model was applied on a beat-to-beat basis to evaluate the arterial mechanical characteristics in seven conscious rats. Ascending aortic arterial pressure (AP) and blood flow were recorded during steady-state in basal conditions, during infusions of isoprenaline, sodium nitroprusside, and phenylephrine, and after intravenous atenolol injection. For each cardiac ...
Supowit S C - - 1998
We previously demonstrated that the neuronal expression of calcitonin gene-related peptide (CGRP), a potent vasodilator, is increased in deoxycorticosterone-salt-induced hypertension where it acts as a compensatory vasodilator to attenuate the elevated blood pressure. To determine whether CGRP is playing a similar role in subtotal nephrectomy-salt-induced hypertension, hypertension was induced in ...
Somody L - - 1998
The way in which the cardiovascular system adapts to weightlessness is still under discussion. No data are yet available on the responses of rats during space flight, although this animal is commonly used in simulation studies. We have designed and tested a protocol to study the short term responses of ...
Hashimoto M - - 1998
Fish oils have been shown to lower blood pressure in hypertensive subjects. All-cis-5,8,11,14,17-icosapentaenoate (EPA), one of the omega-3 polyunsaturated fatty acids, is known to be one of the major active components in fish oil that has beneficial effects on the cardiovascular system. However, little is known about the antihypertensive effect ...
Zhang Z B - - 1998
AIM: To investigate the effects of 1-(2,6-dimethylphenoxy)-2-(3,4-dimethoxyphenylethylamino) propane hydrochloride (DDPH) on cardiac systolic and diastolic function, lactate dehydrogenase (LDH) activity, and LDH isoenzymes in rats with cardiac hypertrophy. METHODS: The cardiac hypertrophy of rats was induced by partly occluding abdominal aorta. The rats were given i.g. DDPH for 8 wk ...
Kim S Y - - 1997
Mivazerol, 3-[1(H-imidazol-4-yl)methyl]-2-hydroxybenzamide hydrochloride, is a selective alpha 2-adrenoceptor agonist designed for the prevention of myocardial infarction in perioperative patients. Because unintended hypothermia occurs frequently during surgery, we were interested, in this study, to examine the relationship between body temperature and the bradycardic response induced by mivazerol. Experiments were carried out ...
Capers Q Q - - 1997
Monocyte chemoattractant protein-1 (MCP-1), a potent monocyte chemoattractant synthesized by vascular cells and monocytes, has been proposed to be an important mediator of inflammatory responses in the arterial vasculature. It was recently demonstrated that hypertension is associated with an inflammatory response in the arterial wall. To determine the effect of ...
Cicila G T - - 1997
11 beta-hydroxylase (Cyp11b1) mutations were previously linked to altered steroid biosynthesis and blood pressure in Dahl salt-resistant (R) and Dahl salt-sensitive (S) rats. In the present work, interval mapping identified a putative blood pressure quantitative trait locus (QTL) near Cyp11b1 in an F1(SxR)xS population (LOD = 2.0). Congenic rats (Designated ...
Wang C - - 1997
The tissue kallikrein-kinin system is involved in vasodilation and blood pressure regulation. In the present study, we investigated the effects of chronic cyclosporin A (CsA) administration on blood pressure and the expression of tissue kallikrein, kininogen, and bradykinin receptor in normotensive Wistar rats. Chronic administration of CsA significantly increased systolic ...
Becker R H - - 1997
Subchronic bolus administration of the angiotensin-converting-enzyme inhibitor ramipril caused a dose-dependent (0.1 to 10 mg.kg-1.d-1), yet each in his own way 24-hour sustained, reduction in arterial blood pressure in conscious unrestrained spontaneously hypertensive rats with telemetric recording, and 0.01 mg.kg-1.d-1 was a no-effect dose. This was accompanied by dose-dependent attenuation ...
Ito S - - 1997
We have previously reported that inhibition of the nucleus of the solitary tract (NTS) in chronically sinoaortic baroreceptor-denervated (SAD) rats has no effect on blood pressure in contrast to the marked increase in blood pressure it elicits in baroreceptor-intact rats. This could result either from a lack of tonic excitatory ...
Amann K - - 1997
In previous studies on experimental renal failure, hypertrophy of cardiomyocytes, diminished capillarization, and increased intercapillary distances had been observed, abnormalities that will expose the heart to reduced ischemia tolerance. It has not been established, however, whether such structural alterations are unique for the heart (eg, as a consequence of left ...
Morgan T J - - 1997
OBJECTIVES: To test the rapidity of a continuous PCO2 measurement system response to brief reductions in gut perfusion from transient episodes of graded aortic hypotension, and to investigate the relationship between the increase in ileal luminal PCO2 and mean aortic pressure during the episodes. DESIGN: Prospective, experimental animal study. SETTING: ...
Haywood J R - - 1997
One-kidney, figure-8 renal wrap or sham operation was performed on male and female rats to determine if a difference existed in the expression of hypertension between the sexes. Animals were prepared with radiotelemetry transmitters to monitor mean arterial pressure and heart rate continuously throughout an 8-week study. Dietary sodium content ...
Zhang Q Y - - 1997
The renin locus (Ren) on rat Chromosome (Chr) 13 had previously been shown to cosegregate with blood pressure in crosses involving Dahl salt-sensitive (S) and Dahl salt-resistant (R) rats. In the present work, interval mapping of blood pressure on Chr 13 with a large F2 (S x R), n = ...
Fazan R R - - 1997
In conscious chronic (12 to 18 weeks) streptozotocin diabetic rats, we examined the changes in basal heart rate, with particular attention to heart rate variability assessed by evaluating the standard deviation (bpm) of the lengths of adjacent pulse pressure. We also investigated in anesthetized rats the ability of the aortic ...
Verma S - - 1997
We previously demonstrated that mesenteric arteries from hyperinsulinemic, insulin resistant fructose hypertensive (FH) rats contain a higher absolute amount of ET-1 and exhibit defective endothelium-dependent vasodilation. Furthermore, chronic ET receptor blockade with bosentan completely prevented the rise in blood pressure in these rats. The present study was undertaken to examine ...
Sun Z - - 1997
The purpose of this study was to determine whether beta-adrenergic receptors are involved in the elevation of blood pressure, tachycardia, and cardiac hypertrophy in rats chronically exposed to cold (5 degrees C). Four groups of rats were used. Two groups of rats were exposed to 5 degrees C and the ...
Koyama K - - 1997
A herbicide, Basta (BASTA), containing glufosinate ammonium (GLA) as the main component and an anionic surfactant, sodium polyoxyethylene alkylether sulfate (AES), causes hemodynamic changes characterized by a decrease in total vascular resistance with an increase or a decrease in cardiac output in human acute oral poisoning. With a motivation based ...
Masumoto N - - 1997
In order to determine whether protein tyrosine kinase mechanisms are involved in pressure-induced contraction, we compared effects of three structurally unrelated tyrosine kinase inhibitors and orthovanadate, a tyrosine phosphatase inhibitor, on the pressure-induced contraction of the posterior cerebral artery isolated from rats. The change in vessel diameter was continuously measured ...
Coulson C C - - 1997
OBJECTIVE: Our purpose was to determine the cardiac effects of oxytocin in the isolated perfused rat heart model and to see whether pregnancy or pharmacologic levels of magnesium modifies the hormone's action. STUDY DESIGN: Hearts were excised from 30 female Sprague-Dawley rats (15 pregnant, 15 nonpregnant) and attached to a ...
Somody L - - 1997
This experiment was a feasibility study which consisted in investigating arterial blood pressure and heart rate to transient and repeated exposure to microgravity in eight unrestrained rats previously implanted with radio-telemetry transmitter. The aim was to perform such recordings throughout all the phases of a parabola during parabolic flights. This ...
Vleeming W - - 1997
The effect of nitrite on blood pressure and heart rate was studied in anaesthetized (non-telemetric method) and free-moving rats (biotelemetry system). In anaesthetized rats, NaNO2 (10-1000 mumol/kg), infused over 5 min, induced a dose-related decrease in blood pressure. The maximal decrease in mean arterial blood pressure (MAP), caused by 1000 ...
Jauchem J R - - 1997
1. The purpose of this study was to examine effects of the beta(1)-adrenoreceptor antagonist esmolol (infused at 2 or 4 mg kg-1 body wt min-1) on heart rate, blood pressure, respiratory rate, localized body temperature changes, survival times, and lethal body temperatures that occur during the exposure of anaesthetized rats ...
Romppanen H - - 1997
The levels of adrenomedullin (ADM), a newly discovered vasodilating and natriuretic peptide, are elevated in plasma and ventricular myocardium in human congestive heart failure suggesting that cardiac synthesis may contribute to the plasma concentrations of ADM. To examine the time course of induction and mechanisms regulating cardiac ADM gene expression, ...
Carlsson P O - - 1997
This study was performed to measure pancreatic islet capillary pressure under basal conditions and after an acute glucose stimulation of insulin release in normal rats. In addition, the islet capillary pressure was estimated in GK rats, an animal model of NIDDM. Hydrostatic pressure in single pancreatic islet capillaries was determined ...
Abassi Z - - 1997
It is believed that the hypertensive effect of diaspirin crosslinked hemoglobin, a viable blood substitute, can be resolved by polymerization, which reduces the diffusion of this derivative into the interstitial space between nitric oxide-producing endothelium and the target vascular smooth muscle. We studied the systemic and renal responses to infusion ...
Omran M A - - 1997
1. The effect of Egyptian cobra (Naja haje) venom on the normal electrical activity of the cardiac muscles (ECG) and arterial blood pressure of envenomated rats were investigated in this study. 2. Rats were divided into three groups. The first group was injected im with saline and considered as control ...
Emanueli C - - 1997
We evaluated if chronic blockade of bradykinin B2-receptors by the long-acting antagonist Icatibant (D-Arg,[Hyp3,Thi5,D-Tic7,Oic8]-bradykinin) affects blood pressure of rats. Pairs of normotensive Wistar Kyoto rats or spontaneously hypertensive rats were mated and their offspring received Icatibant (25 nmol day-1 per kg body wt., s.c.) or vehicle from the 2nd day ...
Zanchi A - - 1997
Distensibility of the carotid artery is not altered 2 weeks after renal artery clipping despite adaptive vascular hypertrophy related to hypertension. The purpose of this study was to assess arterial wall behavior with hypertension persisting for a longer period. Male Wistar rats were examined 1, 5, 9, and 24 weeks ...
Yamamoto S - - 1997
The antihypertensive effects of valsartan ((S)-N-valeryl-N-¿[2'-(1H-tetrazol-5-yl)biphenyl-4-yl]methyl¿ valine, CAS 137862-53-4, CGP 48933), an angiotensin II type 1 receptor antagonist, were examined in hypertensive rats and dogs. In normotensive rats and deoxycorticosterone acetate (DOCA)/salt hypertensive rats, valsartan had no effect on blood pressure. Single oral administrations of valsartan at doses of 3-30 ...
Lacasse-M S - - 1997
To investigate the role of uremia in the development of human recombinant erythropoietin (r-HuEPO)-induced hypertension, Wistar rats were divided into a uremic (subtotal nephrectomy) and a control group. After three weeks, both groups were again divided and each subgroup received either r-HuEPO (100 u/kg s.c., 3 times weekly) or the ...
Shiozaki T - - 1997
The effects of microinjection of serotonin-1 (5-HT1) antagonist methiothepin and 5-HT1 agonist buspirone into the nucleus reticularis parvocellularis were investigated in the anaesthetized rats. Methiothepin produced an increase in arterial blood pressure when injected into the left side, but it did a decrease when injected into the right side. On ...
Verma S - - 1997
OBJECTIVES: To determine the effects of calcium antagonists on hyperinsulinemia, hypertriglyceridemia and hypertension, we examined the long-term effects of a new calcium channel blocker, mibefradil, on plasma insulin levels, plasma triglyceride levels and systolic blood pressure in insulin-resistant and hyperinsulinemic fructose-hypertensive (FH) rats. To this aim, both prevention and reversal ...
Lundie M J - - 1997
OBJECTIVE: To compare, using data from published studies, the efficacy of chronic inhibition of the renin-angiotensin system in inducing persistent downregulation of hemodynamic and cardiovascular structural changes in an adult rat with established genetic hypertension with the widely accepted known downregulation in young genetically hypertensive rats. STUDY SELECTION: We report ...
Di Paola Eugenio D - - 1997
1. The effects of the ACE inhibitor enalapril were studied in rats with cardiac hypertrophy induced by abdominal aortic constriction. This experimental model has shown that pump failure can be evidenced only during increased workload. 2. Under basal conditions, enalapril at 1-3 mg/kg induced a significant reduction in blood pressure. ...
Overton J M - - 1997
We tested the hypothesis that food restriction would attenuate the development of hypertension in spontaneously hypertensive rats (SHR). Furthermore, we hypothesized that food restriction would reduce the tonic sympathetic nervous system support of blood pressure in the SHR. Male SHR (Charles River, age 5 wk) were randomly assigned to ad ...
Haefliger J A - - 1997
BACKGROUND: Connexin43 (Cx43), a membrane protein involved in the control of cell-to-cell communication, is thought to play a role in the contractility of the vascular wall and in the electrical coupling of cardiac myocytes. The aim of this study was to investigate the effects of experimental hypertension on Cx43 expression ...
Ruiz-Opazo N - - 1997
The early and sustained deinduction of alpha 2 Na,K-ATPase gene expression in both cardiac left ventricle and aorta in various pressure-overload rat models and in hypertrophied human heart suggests a common transcriptional pressure response mechanism to pressure overload in both rats and humans. To test this hypothesis, we developed transgenic ...
Bealer S L - - 1997
In vivo microdialysis was used to measure extracellular concentrations of norepinephrine in the diagonal band of Broca (DBB) during changes in blood pressure in conscious rats. Dialysate norepinephrine concentration was significantly increased during acute hypertension (280 +/- 40% of control), but was not changed by hypotensive hemorrhage. These results are ...
Sventek P - - 1997
BACKGROUND: Vascular expression of the endothelin-1 gene may be associated with severe vascular hypertrophy. Because in rats, inhibition of NO synthase with the L-arginine analogue N omega-nitro-L-arginine methyl ester (L-NAME) induces blood pressure elevation associated with little cardiovascular hypertrophy, we studied vascular endothelin-1 gene expression in L-NAME-treated rats and the ...
Gangula P R - - 1997
Inhibition of nitric oxide production with NG-nitro-L-arginine methyl ester (L-NAME) increases blood pressure and fetal mortality in pregnant rats. We previously reported that administration of calcitonin gene-related peptide (CGRP) reduces the blood pressure and fetal death produced by L-NAME. To determine the hemodynamic role of endogenous CGRP in this setting, ...
Springate J - - 1997
The recent development of a transgenic rat strain bearing the mouse ren-2 renin gene [TGR(mRen2)27] has provided a new monogenetic model of hypertension. Other hypertensive rat strains are characterized by a blunted pressure-diuresis-natriuresis response such that higher renal perfusion pressures are required to excrete normal amounts of water and sodium. ...
Malele R S - - 1997
A methanol extract of Syzygium guineense bark inhibited intrinsic contractions of rabbit isolated ileum. The inhibition, at bath concentrations of 0.5 - 2.0 mg/ml, was dose-related but non-linear. It produced sustained hypotension in anaesthetized rats. A dose of 5 ug lowered systolic, diastolic and mean blood pressure by 16%, 22% ...
Tutterová M - - 1997
Chronic renal insufficiency (CRI) is often associated with cardiovascular disease; however, its underlying mechanisms are not completely understood. Therefore, in the present study, myocardial functions and metabolic changes were investigated using an animal model of CRI in subtotally nephrectomized rats. In addition, some other parameters, considered risk factors of cardiovascular ...
Jiang J - - 1997
We describe a method of using a micro-tip transducer to measure cerebrospinal fluid pressure (CSFp) through a lateral ventricular cannula in unanesthetized, restrained, non-stressed rats. The mean value of CSFp under the anesthesia was 4.2 +/- 0.9 (mean +/- SEM, n = 6), ranging from 1.3 to 7.5 mmHg. Measurements ...
Gören Z - - 1997
Gamma-aminobutyric acid (GABA) plays an important role in the central control of cardiovascular functions. Previous evidence indicates that a tonically active GABAergic system exists in forebrain structures. The purpose of this study was to examine the role of the unilateral lesion of the central nucleus of amygdala, paraventricular or dorsomedial ...
Sapsed-Byrne S - - 1996
Visceromotor and cardiovascular responses to colonic distension were measured in female rats, anesthetized with halothane in oxygen, in the proestrus, estrus, metestrus and diestrus phases of the estrous cycle. Ten rats were studied in each group and responses were measured at 5-min intervals for 60 min. A mixed model analysis ...
Sun Z - - 1996
In most forms of experimentally induced hypertension in rats, females develop a less severe form of the disease than males. The objective of the present study was to compare the two genders with respect to the development of cold-induced hypertension. The results of the study indicate that both males and ...
Hamet P - - 1996
Left ventricular hypertrophy remains a significant clinical problem and a predictor of fatal outcome in hypertension. Blood pressure per se and environmental modifiers including stress affect cardiac mass. Heat shock proteins are involved in the stress response as well as in the regulation of cardiac growth and cytoprotection. The present ...
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