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Results 251 - 300 of 1444
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Yang Hsin-Yi - - 2004
The aim of the present study was to investigate the anti-hypertensive and angiotensin-converting enzyme (ACE) inhibition effects of soyabean protein hydrolysate in spontaneously hypertensive rats (SHR). Soyabean protein hydrolysate was prepared by peptic hydrolysis and was added into the feed of SHR (0% for the S0 group, 0.5% for the ...
Albaladejo Pierre - - 2004
BACKGROUND: The heart rate (HR) reduction obtained by ivabradine is associated in rats with a decrease in diastolic blood pressure (DBP) and mean blood pressure (MBP), and with an increased pulsatile carotid arterial diameter. OBJECTIVE: To determine, in spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats, whether acute reductions of ...
Hayakawa Kazuhito - - 2004
We investigated the blood-pressure-lowering effects of gamma-aminobutyric acid (GABA) and a GABA-enriched fermented milk product (FMG) by low-dose oral administration to spontaneously hypertensive (SHR/Izm) and normotensive Wistar-Kyoto (WKY/Izm) rats. FMG was a non-fat fermented milk product produced by lactic acid bacteria, and the GABA contained in FMG was made from ...
Sutoo Den'etsu - - 2004
The mechanism by which music modifies brain function is not clear. Clinical findings indicate that music reduces blood pressure in various patients. We investigated the effect of music on blood pressure in spontaneously hypertensive rats (SHR). Previous studies indicated that calcium increases brain dopamine (DA) synthesis through a calmodulin (CaM)-dependent ...
Skov K - - 2004
Renal vascular resistance is increased in essential hypertension, as in genetic models of hypertension. Here we review the evidence that this is at least in part due to structural changes in the afferent arterioles. Rat studies show that the renal afferent arteriole is structurally narrowed in young and adult spontaneously ...
Itoh Tetsuji - - 2004
We investigated the difference in mechanical function after ischemia and reperfusion between Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) or stroke-prone SHR (SHRSP) using the isolated working heart model, in order to examine postischemic mechanical dysfunction in the severely hypertrophied heart. Systolic blood pressure of SHRSP was higher than ...
Toblli J E - - 2004
In previous experiments, our group demonstrated morphological changes in erectile tissue from male spontaneously hypertensive rats (SHR). The present study was performed to determine whether an angiotensin II receptor blocker could protect cavernous tissue (CT) from these structural alterations in SHR. Male SHR and Wistar-Kyoto (WKY) rats were studied during ...
Laakso Juha T - - 2004
BACKGROUND: Hyperuricaemia and reactive oxygen species have recently been associated with essential hypertension. Xanthine oxidoreductase (XOR) produces urate and, in its oxidase isoform, reactive oxygen species also. Our previous studies indicated that hypertension-prone rat strains have greater renal XOR activity than their normotensive counterparts, and that dietary sodium modifies renal ...
Milei José - - 2004
BACKGROUND: Baroreflex and chemoreflex mechanisms play an important role in the dynamic adjustments of circulation and ventilation during daily life. Recently, we have observed atrophy and marked fibrosis in carotid glomus (CG) from old patients with carotid atherosclerosis who died following stroke. However, a possible limitation to interpretation of the ...
Woodard Geoffrey E - - 2004
Although important advances have been made over past decades in studying the mechanisms of hypertension, the nature of cellular signaling patterns involved and their relationship remain unclear. High cGMP production rates in isolated renal glomeruli have been presented as a characteristic of spontaneously hypertensive rat (SHR) even before the development ...
Ndisang Joseph F - - 2004
The enzymatic action of heme oxygenase yields carbon monoxide, biliverdin and iron. Carbon monoxide is implicated in many physiological processes, including the regulation of vascular tissue contractility and apoptosis. By stimulating the soluble guanylyl cyclase (sGC)/cGMP pathway and activating K channels in vascular smooth muscle cells (SMCs), carbon monoxide relaxes ...
Escudero Eduardo Manuel - - 2004
AIMS: The present study was attempted to determine whether LV midwall mechanics yielded different conclusions about LV systolic function than the assessment of endocardial LV mechanics by echocardiography in spontaneously hypertensive rats (SHR). METHODS AND RESULTS: Thirty-six (18 Wistar normotensive (W), 18 [SHR]) anesthetized rats were studied with two-dimensional directed ...
Metcalfe Beverly L - - 2004
The role of the angiotensin II type-2 receptor (AT2R) in cardiac hypertrophy remains elusive despite its demonstrated involvement in cardiovascular development. We have previously shown that a lentiviral vector gene delivery system is able to transduce cardiac tissue with high efficiency in vivo. Using such an approach, our objectives in ...
Fukuda Shunichi - - 2004
The mechanisms for elevation of peripheral vascular resistance in spontaneously hypertensive rats (SHR), a glucocorticoid-dependent form of hypertension, are unresolved. An increase in hemodynamic resistance caused by circulating blood may be a factor. Physiological fluid shear stress induces a variety of responses in circulating leukocytes, including pseudopod retraction. Due to ...
Aguila Marcia Barbosa - - 2004
BACKGROUND: The nature of dietary lipid intake contributes to blood pressure control. OBJECTIVE: To test whether different edible lipid compounds are either beneficial or harmful to blood pressure and cardiac and aortic structure. METHODS: Six groups of 3-month-old male spontaneously hypertensive rats (n = 5) received different edible oils (fish, ...
Kishi Takuya - - 2004
BACKGROUND: Oxidative stress increases in hypertension. The aim of this study was to determine whether reactive oxygen species (ROS) are increased in the rostral ventrolateral medulla (RVLM) in the brainstem, where the vasomotor center is located, in stroke-prone spontaneously hypertensive rats (SHRSP), and, if so, to determine whether the increased ...
Civantos Beatriz - - 2004
It has been suggested that the combination of dietary Ca and Ca2+ channel antagonists could have a synergic antihypertensive effect. In this study, 3-week-old male spontaneously hypertensive rats (SHR) were randomized into four groups of animals. Two of these groups were fed on a normal Ca diet (Ca 1%) and ...
Sharma Jagdish N - - 2004
There is evidence that the kallikrein-kinin system (KKS) is an important mediator in the regulation of blood pressure, and cardiac and renal hemodynamics. The present study was designed to examine the effect of tissue kallikrein and Trasylol, an inhibitor of tissue kallikrein, on survival time after continuous (prolonged) coronary artery ...
Cingolani Oscar H - - 2004
Pressure-overload left ventricular hypertrophy (LVH) is characterized by an increase in myocyte size and fibrosis. However, it is not clear how each of these components affects hypertensive heart disease (HHD). We have shown in 2 different rat models of hypertension that cardiac fibrosis can be reduced with N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP), an ...
Kansui Yasuo - - 2004
Blockade of the renin-angiotensin system improves the impaired endothelium-dependent relaxations associated with hypertension and aging, partly through amelioration of endothelium-derived hyperpolarizing factor (EDHF)-mediated responses. Although the nature of EDHF is still controversial, recent studies have suggested the involvement of gap junctions in EDHF-mediated responses. Gap junctions consist of connexins (Cx), ...
Hughes Jennifer M - - 2004
OBJECTIVE: This study investigated the relationship between the arterial media thickness : lumen diameter (M : L) ratio and arterial contractile responses in the spontaneously hypertensive rat (SHR) and its Wistar-Kyoto control (WKY) under isobaric conditions. METHODS: Femoral arteries with an experimentally reduced M : L ratio were produced in ...
Boesen Erika I - - 2004
Hypertension in spontaneously hypertensive rats (SHR) has been permanently abolished by aggressive treatment regimens targeted against the sympathetic nervous system and adrenal medulla, initiated during the pre-weaning period (guanethidine and nerve growth factor antiserum combined with either adrenal demedullation or prazosin treatment). To investigate the components of the sympatho-adrenal system ...
Lessard Andrée - - 2004
Tachykinins are involved in the central autonomic control of blood pressure. In the present study, we examined the i.c.v. cardiovascular effects of several tachykinin receptor antagonists in awake spontaneously hypertensive rats (SHR, 15 weeks old). Results showed that two tachykinin NK(3) receptor antagonists (R-820: 3-indolylcarbonyl-Hyp-Phg-N(Me)-Bzl and SB 222200: (S)-(-)-N-(alpha-ethylbenzyl)-3-methyl-2-phenylquinoline-4-carboxamide) caused ...
Racasan Simona - - 2004
BACKGROUND: Exposure of normotensive rats to angiotensin-converting enzyme (ACE) inhibitors in early life causes hypertrophy of intrarenal arteries. Similar defects have been found in knockout mice lacking angiotensinogen, ACE, or angiotensin II type 1 (AT1) receptors. On the other hand, transient inhibition of the renin-angiotensin system from 2 weeks of ...
Tokunaga Katsu-hiko - - 2004
We have shown that Protease N treated Royal Jelly (ProRJ) and peptides from ProRJ (Ile-Tyr (IY), Val-Tyr (VY), Ile-Val-Tyr (IVY)) inhibited angiotensin I-converting enzyme (ACE) activity and they have an antihypertensive effect in repeated oral administration for 28 d on spontaneously hypertensive rats (SHR). We investigated the contributive ratio of ...
Hughes Jennifer M - - 2004
In the present study, myogenic properties of femoral arteries from control hindlimbs and those distal to external iliac artery partial ligation of spontaneously hypertensive rats (SHRs) and normotensive Wistar-Kyoto (WKY) rats were assessed. Arterial pressure was reduced distal to the ligature in both strains. Media thickness/lumen diameter (M/L) ratios of ...
Black M Jane - - 2004
BACKGROUND: Reductions in renal filtration surface area (FSA) have been linked to development of hypertension. This study investigated whether there are direct relationships, in the adult rat, between levels of blood pressure and nephron number or total renal FSA. METHODS: F1 and F2 offspring were generated from a spontaneously hypertensive ...
Robin Sophie - - 2004
Hyperhomocysteinemia is often associated with an increase in blood pressure. However our previous study has shown that methionine supplementation induced an increase in blood pressure in Wistar-Kyoto (WKY) rats and a decrease in blood pressure in spontaneously hypertensive rats (SHR) with significant differences in plasma homocysteine (Hcy) metabolites levels. Previously ...
Chen H B - - 2004
Neurada procumbens is a desert plant in the Arabian Peninsula. It has been considered edible by Bedouin and has been used traditionally as a medicinal herb. During a screening test of Arabian plants, the aqueous extract of Neurada procumbens increased the blood pressure of anaesthetized normotensive rats when it was ...
Kett Michelle M - - 2004
The aims of this study were to examine whether combined blockade of alpha(1) and beta-adrenoceptors with carvedilol postweaning affected the development of hypertension and renal vascular narrowing in spontaneously hypertensive rats (SHR), and whether these effects on pressure and renal vascular changes persisted after treatment withdrawal. From 4 to 12 ...
Wu Hung-Chien - - 2004
If acupuncture is able to prevent hypertrophy of the heart, it could therefore prevent the heart from overloading and thus prevent heart failure or sudden death. We therefore studied the effects of acupuncture on blood pressure and cardiac muscle cells. Rats with spontaneous hypertension were divided into three acupuncture treatment ...
Girchev R - - 2004
Spontaneously hypertensive rats (SHR) and normotensive Wistar rats were treated with the endothelin(A) (ET(A)) receptor antagonist BQ-123 16.4 nmol/kg.min i.v. at an infusion rate of 25 microl/min for 50 min. Blood pressure was measured in the femoral artery with a Gould/Statham P23ID transducer connected to the computerized data acquisition system ...
Tanaka T - - 2004
In investigating the influence of chronic cigarette smoke exposure on hypertension, we compared the pharmacodynamic effects of enforced exposure to smoke on spontaneously hypertensive rats (SHR) with those on Wistar-Kyoto (WKY) rats. Chronic cigarette smoke exposure for 8 weeks decreased the elevated heart rate of mature male SHR to approximately ...
Cejka J - - 2004
Cardiovascular effects of LVV-hemorphin-7, a member of the family of fragments from beta-chain of human or bovine hemoglobin, were studied in conscious spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats by radiotelemetry. Intraperitoneal injection of hemorphin in a dose of 100 microg/kg significantly decreased blood pressure in SHR, whereas negligible effect ...
Fukuda Satoshi S International Space Radiation Laboratory, National Institute of Radiological Sciences, Anaganwa, Inage-ku, Chiba-shi, Chiba, - - 2004
Age-related changes in hematological values, serum biochemical constituents, and weights of various organs in both sexes of the Spontaneously Hypertensive (SHR/Izm), Stroke-prone SHR (SHRSP/Izm), and Wistar Kyoto (WKY/Izm) rat strains, bred under SPF conditions, were examined to obtain fundamental data. The body weights from 3-30 weeks and systolic blood pressure ...
Roach Daniel - - 2003
BACKGROUND: Heart rate turbulence (HRT) is a transient tachycardia-bradycardia that follows premature ventricular complexes (PVCs). The physiology of turbulence is studied in the electrophysiology lab using induced premature ventricular stimuli but the reliability of this model for HRT is unknown. OBJECTIVES: To compare heart rate and blood pressure signatures of ...
Moreira Thiago Santos - - 2003
Peripheral treatment with the cholinergic agonist pilocarpine induces intense salivation that is inhibited by central injections of the alpha2-adrenergic/imidazoline receptor agonist moxonidine. Salivary gland blood flow controlled by sympathetic and parasympathetic systems may affect salivation. We investigated the changes in mean arterial pressure (MAP) and in the vascular resistance in ...
Gouldsborough Ingrid - - 2003
BACKGROUND: Young (4 week) spontaneously hypertensive rats (SHR) exhibit greater renal responses to angiotensin II (Ang II) than normotensive Wistar Kyoto (WKY) rats. SHR pups cross-fostering to a WKY dam at birth (SHRX) are less sensitive to Ang II and have lower adult blood pressure. The aim of this study ...
Lin Yingzi - - 2003
We have previously reported that urotensin II acts on the central nervous system to increase blood pressure in normotensive rats. In the present study, we have determined the central cardiovascular action of urotensin II in spontaneously hypertensive rats (SHR). Intracerebroventricular (ICV) injection of urotensin II elicited a dose-dependent increase in ...
Dietz John R - - 2003
1. The aim of the present studies was to determine the role of proANP (1-30) in the regulation of arterial pressure. It was hypothesized that blocking endogenous proANP (1-30) would exacerbate the hypertension in susceptible animal models. 2. Pentobarbital-anaesthetized spontaneously hypertensive rats (SHR) were pretreated i.v. with 1.2 mL rabbit ...
Newaz M A - - 2003
Involvement of free radicals and nitric oxide (NO) has long been implicated to the pathogenesis of essential hypertension. Several studies using antioxidants as the radical scavenger have shown to confer protection against free radical mediated diseases. This study is designed to investigate the role of antioxidant gamma-tocotrienol on endothelial nitric ...
Kuoppala Antti - - 2003
OBJECTIVES: Bradykinin exerts cardioprotective effects through bradykinin type-2 receptors (BK-2Rs). After acute myocardial infarction in rat, the heart adapts by increasing its number of BK-2Rs. However, in human chronic end-stage heart failure, the number of BK-2Rs is significantly decreased. Thus, the presence of a cardioprotective BK-2R signaling system may be ...
Ge Chang-jiang - - 2003
OBJECTIVE: To investigate the structural changes of aorta, and evaluate the effects of atorvastatin on the remodeling of thoracic aorta in spontaneously hypertensive rats (SHR). METHODS: Twelve eight-week-old SHR were randomized into atorvastatin treated group (ATV group, n=6) and distilled water group (DW group, n=6); Wistar-Kyoto rats (WKY) were used ...
Rodenbaugh David W - - 2003
Older individuals (>50 years of age) are increasingly sustaining spinal cord injuries (SCI) and often have pre-existing medical conditions, including hypertension. Furthermore, the life expectancy of individuals with paraplegia has increased to near that of able-bodied individuals. Thus, chronic diseases associated with aging (e.g. hypertension) are increasing in this population. ...
Amenta Francesco - - 2003
Hypertension is an important risk factor for cerebrovascular disease including stroke and has also a role in the development of vascular cognitive impairment (VCI) and vascular dementia (VaD). Research on pathophysiology and treatment of hypertensive brain damage may benefit from the availability of animal models. This paper has reviewed the ...
Aoki Hideyuki - - 2003
GABA-enriched tempeh-like fermented soybean (GABA-tempeh) was supplemented to the AIN-76 diet and fed for 2 months to spontaneously hypertensive rats (SHRs), an animal model of spontaneously developed hypertension, to compare the antihypertensive activity with that of authentic GABA. The elevation of systolic blood pressure in SHRs was significantly retarded in ...
Boesen Erika I - - 2003
1. The neonatal/preweaning period appears to represent a critical period of involvement of the sympathetic nervous system in the development of hypertension in spontaneously hypertensive rats (SHR). 2. We tested whether alpha1-adrenoceptor-mediated effects during the preweaning period are involved in the development of hypertension in the adult SHR. 3. Male ...
Ji Yong - - 2003
OBJECTIVES: To compare the effects of the sodium-hydrogen exchange blocker, amiloride, with those of the angiotensin-converting enzyme inhibitor, enalapril, on cardiac structure and function and intracardiomyocyte calcium concentration ([Ca2+]i) and pH (pHi), in spontaneously hypertensive rats (SHRs). METHODS: Experiments were performed in SHRs treated for 4 weeks with amiloride 7.5 ...
Briones Ana M - - 2003
Chronic hypertension is associated with resistance artery remodelling and mechanical alterations. However, the contribution of elastin has not been thoroughly studied. Our objective was to evaluate the role of elastin in vascular remodelling of mesenteric resistance arteries (MRA) from spontaneously hypertensive rats (SHR). MRA segments from Wistar Kyoto rats (WKY) ...
Albaladejo P - - 2003
BACKGROUND: A reduction of heart rate (HR) by surgical means or pharmacological agents affects the progression and/or regression of atherosclerotic lesions. Nevertheless, the effect of bradycardia per se on large artery structure and function has never been investigated in rat models of hypertension. METHODS: Four groups of Wistar-Kyoto (WKY) rats ...
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