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Lavandero S - - 1993
OBJECTIVE: The aim was to clarify the role of cyclic AMP dependent protein kinase (PKA) and changes in mechanical heart function during development of cardiac hypertrophy induced by volume overload. METHODS: Protein and DNA contents, PKA activity, and peak systolic stress-strain relationships in hearts from animals submitted to aortocaval shunt ...
Tuncer M - - 1993
The possible role of endothelium-derived relaxing factor (EDRF) was investigated in resistance vessels of the kidney obtained from spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats. Kidneys were studied in parallel and perfused with Tyrode's solution at constant optimal flow rates. In the presence of indomethacin, during vasoconstriction (increase ...
Heller J - - 1993
Several animal models of genetic hypertension have been developed but not all of them possess a closely related control strain. Therefore, a new model based on Wistar rats is described in which both hypertensive and normotensive lines were bred from a single parental pair. Several basic data on the two ...
Schirner M - - 1993
Spontaneously hypertensive rats (SHR) of the Okamoto strain with blood pressure above 161 mmHg and SHR with blood pressure levels of less than 160 mmHg were treated with oral doses of aspirin (100 mg kg-1) for three days. Whereas the blood pressure of SHR with blood pressure above 161 mmHg ...
Nowack R - - 1993
The influence of Pb exposure on blood pressure was investigated in Wistar Kyoto, Sprague Dawley and stroke prone spontaneously hypertensive rats. In short-term experiments, a dose-dependent decrease of blood pressure was found with administration of Pb acetate in drinking fluid. This effect was more pronounced in young, male as compared ...
Olivetti G - - 1993
OBJECTIVE: In order to determine whether alterations in cardiac function and structure occur early in life in spontaneously hypertensive rats (SHR) and whether the addition of a volume load would affect myocardial growth and haemodynamic performance, SHR were exposed to an iron and copper deficient diet for 12 weeks (SHR-A) ...
Schleiffer R - - 1993
OBJECTIVE: Chronic parathyroidectomy (PTX) attenuates blood pressure and increases vascular force generation. The mechanism is not understood. We tested the hypothesis that PTX-induced changes in blood pressure and vessel contractility result from rapid changes in serum parameters induced by PTX, and the hypothesis that the endothelium-derived factors contribute to PTX-induced ...
Qualy J M - - 1993
The relationship between age and central noradrenergic neuronal activity of the paraventricular hypothalamic nucleus (PVH) was examined in 7- to 10-, 12- to 14-, and 30- to 36-wk-old Sprague-Dawley (SD), Wistar-Kyoto (WKY), and spontaneously hypertensive rats (SHR). As an index of noradrenergic activity, endogenous norepinephrine (NE) overflow was assessed utilizing ...
Lübbe A S - - 1993
Renovascular hypertension profoundly alters skeletal muscle arteriolar responses to sepsis, yet systemic hemodynamics to sepsis are not affected by hypertension. In this study, we hypothesized that microvascular responses of skeletal muscle and systemic hemodynamics are changed during high- and low-cardiac-output Escherichia coli bacteremia in normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive ...
Smith J M - - 1993
To test the hypothesis that dietary fish oil supplementation decrease systolic blood pressure in hypertensive rats by modifying cardiovascular responsiveness to adrenergic agonists, spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY) received either a corn or fish oil diet, 5% (g/kg) for 10 weeks. Mean aortic pressure was lower in ...
Shudo C - - 1993
A new calcium antagonist, NZ-105 ((+/-)-2-[benzyl(phenyl)amino]ethyl 1,4-dihydro-2,6-dimethyl-5-(5,5-dimethyl-2-oxo-1,3,2-dioxaphosphorina n-2-yl)-4- (3-nitrophenyl)-3-pyridinecarboxylate hydrochloride ethanol) (10 mg kg-1, p.o.), showed slow-onset hypotensive effect in spontaneously hypertensive rats (SHRs). The tachycardia evoked by NZ-105 was completely prevented when combined with a beta-adrenoceptor blocker, propranolol (20 mg kg-1), which did not affect the hypotensive response to ...
Ely D L - - 1993
Our laboratory has shown that the Y chromosome has a significant effect on blood pressure in the spontaneously hypertensive rat (SHR) model of hypertension and that the testes and androgen receptor contribute to the blood pressure rise. As an extension of our research, we have developed two new rat strains, ...
Pham I - - 1993
Angiotensin converting enzyme (ACE) and neutral endopeptidase (NEP) are implicated in the metabolism of several peptides involved in blood pressure and sodium homeostasis control, such as angiotensins, atrial natriuretic factor (ANF), bradykinin and endothelin. The effects of a highly selective NEP inhibitor (NEPI), retrothiorphan, of a converting enzyme inhibitor (CEI), ...
Gadowski G R - - 1993
Hypertension has long been suspected to increase the growth rate of abdominal aortic aneurysms (AAA), but there is little experimental evidence to support this hypothesis. Using an established model, aneurysms were induced in normotensive Wistar-Kyoto (WKY) rats and in a unique strain of genetically hypertensive Wistar-Kyoto (WKHT) rats by perfusing ...
Mourlon-Le Grand M C - - 1993
A nonhypotensive dose of atrial natriuretic peptide (ANP) was infused (60 pg/kg body wt per day s.c. by osmotic pump) for 25 days in 16-week-old normotensive Wistar-Kyoto rats (WKYs, n = 12) and age-matched spontaneously hypertensive rats (SHRs, n = 12). During the infusion period, systolic blood pressure, urinary volume, ...
Mennini T - - 1993
The time-course of dihydropyridine receptor occupancy by lacidipine and its relationship with pharmacological activity has been studied in spontaneously hypertensive rat (SHR), as measured by the inhibition of specific (+)-[3H]PN 200-110 binding in-vivo. After oral administration of doses active in reducing blood pressure, lacidipine did not show tissue target differences ...
Young R L - - 1993
There is general agreement that the sympathetic nervous system is involved in the development of hypertension in spontaneously hypertensive rats (SHR). However, in a previous study we established that chronic administration of the selective alpha 1-adrenoceptor antagonist terazosin to SHR failed to prevent this phenomenon. In the present study, we ...
Minami N - - 1993
OBJECTIVE: To determine whether the reduced baroreceptor-heart rate reflex sensitivity in genetically hypertensive rats is related to the level of cardiac or vascular hypertrophy. DESIGN: Young spontaneously hypertensive rats (SHR), stroke-prone hypertensive rats (SHRSP) and Wistar-Kyoto (WKY) rats were treated chronically with the angiotensin converting enzyme (ACE) inhibitor perindopril in ...
Katsuya T - - 1993
Recent advances in molecular biology have allowed the study of the candidate genes for essential hypertension. To identify the genes responsible for basal blood pressure in the spontaneously hypertensive rat strain, the rat model of genetic hypertension, we performed a cosegregation analysis between the genotype and blood pressure in a ...
Olivetti G - - 1993
To test whether angiotensin-converting enzyme (ACE) inhibition may prevent myocardial damage and may affect coronary microvasculature in spontaneously hypertensive rats (SHR), young 5-week-old SHR were treated for 3 months with spirapril and changes in blood pressure (BP) were monitored. Untreated SHR were used as controls. The rats were killed; left ...
Benishin C G - - 1993
OBJECTIVE: Parathyroid hypertensive factor (PHF) is a newly described hypertensive factor which may cause elevation of blood pressure in approximately 40% of North American essential hypertensive patients. PHF is also found in several animal models of hypertension, including spontaneously hypertensive rats (SHR), deoxycorticosterone acetate-salt hypertensive rats and salt-sensitive Dahl rats. ...
Ofosu-Appiah W - - 1993
The effects of recombinant human interleukin-2 covalently linked to polyethylene glycol (PEG-IL-2) or interleukin-2 (IL-2) on hypertension and in vitro suppressor T cell function in the spontaneously hypertensive rats (SHR) were investigated. Male young prehypertensive (4 weeks old) SHRs and adult (10 weeks old) SHRs with established hypertension were injected ...
Wang T M - - 1993
The histomorphometric changes in the proximal tibial metaphysis and epiphyseal growth plate and midtibial shaft of 26-week-old spontaneously hypertensive rats (SHR) compared with those of the corresponding normotensive Wistar-Kyoto (WKY) rats were studied. A decrease in body weight, growth plate thickness, and longitudinal growth rate of the proximal tibial epiphysis, ...
Mukherjee D - - 1993
The myocardium contains a fibrillar collagen matrix that consists primarily of type I and type III collagens. There is a marked alteration in the ratio and amount of collagen phenotypes in myocardial hypertrophy due to pressure overload. The purpose of the present study is (1) to study the effect of ...
Tsoucaris-Kupfer D - - 1993
BACKGROUND: In large animals pulse pressure increases from central to peripheral arteries whereas mean arterial pressure decreases slightly. This haemodynamic pattern has not been verified in small animals, particularly in hypertensive rats before and after administration of antihypertensive drugs. DESIGN: The intra-arterial blood pressure of normotensive Wistar-Kyoto (WKY) rats and ...
Hatton D C - - 1993
To investigate the role of adrenergic receptor activity in dietary calcium-induced alterations in blood pressure, weanling spontaneously hypertensive rats (SHR) were placed on either high-calcium (2.0%) or low-calcium (0.1%) diets for 1-2 wk. Baseline blood pressure was higher and pressor responses to exogenous norepinephrine (NE) were greater in the SHR ...
Bodin P - - 1993
Single-mass primary cultures were used for as long as 5 wk as the source of subcultured vascular smooth muscle cells for the study of their change of shape on the addition of agonists. We have compared the responses to angiotensin II, vasopressin, norepinephrine, and serotonin of myocytes derived from three ...
Okamoto K - - 1993
Effects of reduction of blood pressure and regression of left ventricular hypertrophy following hydralazine and captopril therapy on ischemic cardiac function and myocardial metabolism were studied in spontaneously hypertensive rats (SHR). Hydralazine (1.5 or 3 mg/kg/day) and captopril (50 or 100 mg/kg/day) were administered to SHR from 19 to 26 ...
Brooks W W - - 1993
Left ventricular isovolumic stress development and metabolic parameters were studied in 18-24-month-old spontaneously hypertensive rats (SHRs) and age-matched Wistar-Kyoto (WKY) rat controls using the isolated, isovolumic (balloon in left ventricle) buffer-perfused rat heart preparation. After WKY rats and all SHRs were compared, SHRs were divided into two groups: those animals ...
Patel K P - - 1993
The renal responses to acute volume expansion (VE) were measured from intact and denervated kidneys in 5 week old spontaneously hypertensive rats (SHR). Urine flow and sodium excretion were measured before, during and after VE from innervated and denervated kidneys in anesthetized (Inactin--0.1 g/kg, ip) age and sex matched SHR ...
Jastrzebski Z - - 1993
Acute intravenous toxicity and antihypertensive activity of KB1, a novel todralazine analog was investigated and compared with the effects of todralazine (Td) in normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive (SHR) rats. LD50 values were 72 mg.kg-1 for KB1, and 255 mg.kg-1 for Td in WKY and 43 mg.kg-1 or KB1 ...
McLaren Y - - 1993
OBJECTIVE: To determine whether elevated microviscosity is associated with elevated arterial pressure in segregating (F2) hybrids produced by crossing stroke-prone spontaneously hypertensive rats (SHRSP) and Wistar-Kyoto (WKY) rats. METHODS: SHRSP and WKY rats were obtained from the colony at the University of Heidelberg. F2 progeny were obtained by brother-sister mating ...
Muntzel M - - 1993
Treatment with recombinant human erythropoietin (rHuEPO) successfully reverses anemia in uremic patients. Of major concern, however, are blood pressure increases during rHuEPO therapy, observed particularly in patients with a history of hypertension. The present study was designed to determine whether high-dose rHuEPO elevates blood pressure in nonuremic rats, and if ...
Nishikibe M - - 1993
A newly synthesized ET(A)-selective antagonist, BQ-123, was examined with respect to its anti-endothelin(ET) action in vitro and in vivo and its effect on blood pressure in Wistar Kyoto rats (WKY), spontaneously hypertensive rats (SHR) and stroke-prone spontaneously hypertensive rats (SHRSP). In isolated porcine coronary arteries, BQ-123 (0.07 microM to 6.0 ...
Ikenaga H - - 1993
We investigated the role of the endothelium-derived relaxing factor nitric oxide (NO) on pressure-natriuresis in spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY) using in vivo perfusion studies. Differences in the neural and hormonal background to the kidney were minimized by renal denervation and by holding plasma vasopressin, aldosterone, corticosterone, ...
Benetos A - - 1993
Acute converting enzyme inhibition relaxes arterial smooth muscle and increases arterial compliance in several models of animal and human hypertension. However, it is unknown whether the doses needed for the relaxation of large arteries are similar to those inducing arteriolar relaxation and blood pressure (BP) decrease. To answer this question, ...
Ohlstein E H - - 1993
Until recently, a role for endothelin-1 (ET-1) in the development and/or maintenance of hypertension has been based solely on indirect findings, e.g., elevated circulating levels of peptide. However, with the development of specific ET-1 receptor antagonists it is now possible to examine this relationship directly. The present study describes the ...
Yang T L - - 1993
The neural and nonneural factors contributing to maintain the hemodynamic status in 14 to 16 weeks old stroke prone spontaneously hypertensive rats (SHRSP) and spontaneously hypertensive rats (SHR) were compared with those of the age matched normotensive Wistar Kyoto (WKY) rats under chloralose-urethane anesthesia. The ascending aortic blood flow, arterial ...
Yokokawa K - - 1992
Previous studies have shown that chronic subcutaneous administration of heparin significantly reduces blood pressure in hypertensive rats. The intracellular mechanisms of how heparin prevents smooth muscle cell proliferation remain unclear. This study was designed to examine whether heparin affects endothelin-1 action and production, to further elucidate the mechanism of the ...
Lew M J - - 1992
Passive properties (diameter, wall-to-lumen ratio and axial length) of small mesenteric arteries from SHR and WKY rats were measured with the artery segments cannulated and pressurised, or mounted on wires in a myograph. The measurements were made with a range of distending pressures (or calculated equivalent distending pressures when wire-mounted) ...
Bedford T G - - 1992
To study the influences of 16 wk of endurance training on the reflex regulation of resting blood pressure, nontrained (NT) and trained (T) female hypertensive rats (SHR) were subjected to conditions of lower body negative pressure (LBNP). Measurements of muscle cytochrome oxidase activity and run time to exhaustion indicated that ...
Persson P B - - 1992
This study tests whether the power spectrum of blood pressure (BP) provides information toward the sympathovagal balance of BP control by comparing the BP (femoral arterial catheter) spectrum with the spectrum of the efferent sympathetic nerve activity (SNA, bipolar electrode around splanchnic nerve). A remarkable resemblance between both spectra was ...
Bergström G - - 1992
OBJECTIVE: To investigate the role of the renal medulla in early hypertension in spontaneously hypertensive rats (SHR), and to explore whether the attenuated increase of pressure induced by enalapril treatment is affected by chemical medullectomy. DESIGN: Forty-four male SHR were studied from 5 to 18 weeks of age: 22 remained ...
Kubo M - - 1992
Effects of (4S)-1-methyl-3-[(2S)-2-[N-((1S)-1-ethoxycarbonyl-3-phenylpropyl)amino]- propionyl]-2-oxoimidazolidine-4-carboxylic acid hydrochloride (TA-6366) on morphological change and mechanical property related to sodium ion permeability in the aorta of spontaneously hypertensive rats (SHRs) were examined, as compared with those of enalapril and captopril. Ten-week oral administration of TA-6366 (1 and 5 mg/kg/d) from 4 weeks of age ...
Freslon J L - - 1992
The aim of this study was to determine the morphologic and functional vascular changes occurring following 4 weeks of treatment with the angiotensin-converting enzyme inhibitor trandolapril in the spontaneously hypertensive rat (SHR) in the established phase of hypertension. At the dosage used, 0.4 mg/kg orally, trandolapril decreased blood pressure of ...
Susic D - - 1992
Heparin given over a long term by a subcutaneous route consistently lowers blood pressure in the hypertensive rat models. The decrease in blood pressure is accompanied by a parallel decrease in hematocrit suggesting a causal relationship between hematocrit and blood pressure. The aim of this study was to define the ...
Talib H K - - 1992
Red blood cell Na+ content as well as ouabain-resistant Na+ and Rb+ (K+) transport (susceptible or resistant to inhibition by loop diuretics) were determined in spontaneously hypertensive rats (SHR) and normotensive Brown Norway (BN) rats the erythrocytes of which were incubated in either saline or Mg(2+)-sucrose medium. Elevated ouabain-resistant Na+ ...
Rodionov I M - - 1992
The reactions of resistance vessels in SHR and WKY hindquarters were compared during saline or blood perfusion. During saline constant-flow perfusion at all initial pressures (80-200 mmHg) sympathetic vasoconstrictor effects were greater in SHR than those in WKY. During perfusion at constant and equal pressure vasoconstrictor responses were greater in ...
Mangiarua E I - - 1992
OBJECTIVE: The importance of sympathetic innervation for the development of structural changes in the cerebral arteries of hypertensive animals was studied. DESIGN: Sympathetic denervation was induced with combined treatment from birth of antibody against nerve growth factor and guanethidine. Previous studies from our laboratory showed that this procedure not only ...
Engler M M - - 1992
OBJECTIVE: To determine the effects of dietary gamma-linolenic acid upon blood pressure, aortic reactivity and cholesterol metabolism in spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats. DESIGN: Randomized parallel-group study. METHODS: SHR and WKY rats were fed a purified diet containing either sesame or borage oil rich in gamma-linolenic acid ...
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