Blood pressure reducing effects of Phalaris canariensis in normotensive and spontaneously hypertensive rats

2012 ◽  
Vol 90 (2) ◽  
pp. 201-208 ◽  
Author(s):  
Clévia Santos Passos ◽  
Lucimeire Nova Carvalho ◽  
Roberto Braz Pontes ◽  
Ruy Ribeiro Campos ◽  
Olinda Ikuta ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Antihypertensive Agent ◽  
Spontaneously Hypertensive Rats ◽  
Wistar Rats ◽  
Antihypertensive Effect ◽  
Treatment Interruption ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Baseline Levels ◽  
Phalaris Canariensis

The birdseed Phalaris canariensis (Pc) is popularly used as an antihypertensive agent. The aqueous extract of Pc (AEPc) was administered in adult normotensive Wistar rats and spontaneously hypertensive rats (SHR) and in prehypertensive young SHR (SHRY, 3 weeks old). Animals received AEPc (400 mg·kg–1·day–1, by gavage) for 30 days, then groups were divided into 2 subgroups: one was treated for another 30 days and the other received water instead of AEPc for 30 days. AEPc reduced systolic blood pressure (SBP) in both adult groups; however, treatment interruption was followed by a gradual return of the SBP to baseline levels. SHRY became hypertensive 30 days after weaning. AEPc minimized the increase in SBP in SHRY, but blood pressure rose to levels similar to those in the untreated group with treatment interruption. There were no changes in renal function, diuresis, or Na+ excretion. Pc is rich in tryptophan, and the inhibition of the metabolism of tryptophan to kynurenine, a potential vasodilator factor, prevented the blood pressure reducing effect of AEPc. Moreover, AEPc significantly reduced sympathoexcitation. Data indicate that the metabolic derivative of tryptophan, kinurenine, may be a mediator of the volume-independent antihypertensive effect of Pc, which was at least in part mediated by suppression of the sympathetic tonus.

scholarly journals Antihypertensive Effect ofSyzygium cuminiin Spontaneously Hypertensive Rats

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Rachel Melo Ribeiro ◽  
Vicente Férrer Pinheiro Neto ◽  
Kllysmann Santos Ribeiro ◽  
Denilson Amorim Vieira ◽  
Iracelle Carvalho Abreu ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Spontaneously Hypertensive Rats ◽  
Wistar Rats ◽  
Vascular Reactivity ◽  
Antihypertensive Effect ◽  
Maximum Effect ◽  
Syzygium Cumini ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive

This study evaluated thein vivopotential antihypertensive effect of hydroalcoholic extract ofSyzygium cuminileaves (HESC) in normotensive Wistar rats and in spontaneously hypertensive rats (SHR), as well as itsin vitroeffect on the vascular reactivity of resistance arteries. The hypotensive effect caused by intravenous infusion of HESC (0.01–4.0 mg/kg) in anesthetized Wistar rats was dose-dependent and was partially inhibited by pretreatment with atropine sulfate. SHR received HESC (0.5 g/kg/day), orally, for 8 weeks and mean arterial pressure, heart rate, and vascular reactivity were evaluated. Daily oral administration of HESC resulted in a time-dependent blood pressure reduction in SHR, with a maximum reduction of 62%. In the endothelium-deprived superior mesenteric arteries rings the treatment with HESC reduced by 40% the maximum effect (Emax⁡) of contraction induced by NE. The contractile response to calcium and NE of endothelium-deprived mesenteric rings isolated from untreated SHR was reduced in a concentration-dependent manner by HESC (0.1, 0.25, and 0.5 mg/mL). This study demonstrated thatSyzygium cuminireduces the blood pressure and heart rate of SHR and that this antihypertensive effect is probably due to the inhibition of arterial tone and extracellular calcium influx.

scholarly journals Antihypertensive Effect of Radix Paeoniae Alba in Spontaneously Hypertensive Rats and Excessive Alcohol Intake and High Fat Diet Induced Hypertensive Rats

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Chen Su-Hong ◽  
Chen Qi ◽  
Li Bo ◽  
Gao Jian-Li ◽  
Su Jie ◽  
...  
Keyword(s):  
Blood Pressure ◽  
High Fat Diet ◽  
Spontaneously Hypertensive Rats ◽  
Antihypertensive Effect ◽  
Hdl Cholesterol ◽  
High Fat ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Excessive Alcohol ◽  
Radix Paeoniae Alba

Radix Paeoniae Alba (Baishao, RPA) has long been used in traditional Chinese medicine formulation to treat hypertension by repression the hyperfunction of liver. However, whether the RPA itself has the antihypertensive effect or not is seldom studied. This study was to evaluate the protective effect of RPA on hypertensive rats. Alcohol in conjunction with a high fat diet- (ACHFD-) induced hypertensive rats and spontaneously hypertensive rats (SHR) was constantly received either RPA extract (25 or 75 mg/kg) or captopril (15 mg/kg) all along the experiments. As a result, RPA extract (75 mg/kg) could significantly reduce systolic blood pressure of both ACHFD-induced hypertensive rats and SHR after 9-week or 4-week treatment. In ACHFD-induced hypertensive rats, the blood pressure was significantly increased and the lipid profiles in serum including triglyceride, total cholesterol, LDL-cholesterol, and HDL-cholesterol were significantly deteriorated. Also, hepatic damage was manifested by a significant increase in alanine transaminase (ALT) and aspartate transaminase (AST) in serum. The RPA extract significantly reversed these parameters, which revealed that it could alleviate the liver damage of rats. In SHR, our result suggested that the antihypertensive active of RPA extract may be related to its effect on regulating serum nitric oxide (NO) and endothelin (ET) levels.

scholarly journals Angiotensin II Inhibition Reduces Stress Sensitivity of Hypothalamo-Pituitary-Adrenal Axis in Spontaneously Hypertensive Rats

Endocrinology ◽  
2006 ◽  
Vol 147 (7) ◽  
pp. 3539-3546 ◽  
Author(s):  
Walter Raasch ◽  
Christian Wittmershaus ◽  
Andreas Dendorfer ◽  
Inga Voges ◽  
Friedrich Pahlke ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Angiotensin Ii ◽  
Angiotensin Converting Enzyme ◽  
Hpa Axis ◽  
Spontaneously Hypertensive Rats ◽  
Converting Enzyme ◽  
Hypertensive Rats ◽  
At1 Receptors ◽  
Spontaneously Hypertensive ◽  
Baseline Levels

Angiotensin II type 1 (AT1) receptors are expressed within organs of the hypothalamo-pituitary-adrenal (HPA) axis and seem to be important for its stress responsiveness. Secretion of CRH, ACTH, and corticosterone (CORT) is increased by stimulation of AT1 receptors. In the present study, we tested whether a blockade of the angiotensin II system attenuates the HPA axis reactivity in spontaneously hypertensive rats. Spontaneously hypertensive rats were treated with candesartan (2 mg/kg), ramipril (1 mg/kg), or mibefradil (12 mg/kg) for 5 wk. In addition to baseline levels, CORT and ACTH responses to injection of CRH (100 μg/kg) were monitored over 4 h. mRNA of CRH, proopiomelanocortin, AT1A, AT1B, and AT2 receptors was quantified by real-time PCR. All treatments induced equivalent reductions of blood pressure and had no effect on baseline levels of CORT and ACTH. However, both candesartan and ramipril significantly reduced CRH-stimulated plasma levels of ACTH (−26 and −15%) and CORT (−36 and −18%) and lowered hypothalamic CRH mRNA (−25 and −29%). Mibefradil did not affect any of these parameters. Gene expression of AT1A, AT1B, and AT2 receptors within the HPA axis was not altered by any drug. We show for the first time that antihypertensive treatment by inhibition of AT1 receptors or angiotensin-converting enzyme attenuates HPA axis reactivity independently of blood pressure reduction. This action is solely evident after CRH stimulation but not under baseline conditions. Both a reduced pituitary sensitivity to CRH and a down-regulation of hypothalamic CRH expression have the potential to reduce HPA axis activity during chronic AT1 blockade or angiotensin-converting enzyme inhibition.

Response of blood pressure and cardiac myosin polymorphism to swimming training in the spontaneously hypertensive rat

1982 ◽  
Vol 60 (8) ◽  
pp. 1098-1103 ◽  
Author(s):  
Heinz Rupp ◽  
Ruthard Jacob
Keyword(s):  
Blood Pressure ◽  
Systolic Blood Pressure ◽  
Spontaneously Hypertensive Rats ◽  
Wistar Rats ◽  
Spontaneously Hypertensive Rat ◽  
Hypertensive Rats ◽  
Swimming Training ◽  
Myosin V ◽  
Spontaneously Hypertensive ◽  
Myosin Isoenzyme

Cardiac muscle can adapt to different functional demands, as evidenced by polymorphism of myosin. Pressure load in spontaneously hypertensive rats induced a shift of the myosin isoenzymes towards myosin V3 (18% V1, 27% V2, 55% V3) relative to normotensive Wistar rats (49% V1, 29% V2, 22% V3). A swimming routine with Wistar rats resulted in a shift towards myosin V1 (72% V1, 18% V2, 10% V3). The training effect is not restricted to normotensive rats, since spontaneously hypertensive rats subjected to the same swimming routine exhibited a myosin isoenzyme pattern (38% V1, 31% V2, 31% V3) approaching that of the sedentary Wistar rats. Swimming training can, therefore, prevent the myosin isoenzyme redistribution towards myosin V3 found in sedentary spontaneously hypertensive rats. Furthermore, systolic blood pressure was significantly reduced (130 ± 8 mmHg (1 mmHg = 133.322 Pa)) in the swim-trained compared with the sedentary spontaneously hypertensive rats (157 ± 12 mmHg). The training-induced changes in myosin polymorphism and systolic blood pressure are, at least partially, attributed to substantially normalized sympathetic activity. The functional relevance of swimming training in the spontaneously hypertensive rat is seen in the increased potential of coping with situations requiring fast contraction which may occur during sudden physical exertion or emotional stress.

scholarly journals A Mixture of Phenolic Metabolites of Quercetin Can Decrease Elevated Blood Pressure of Spontaneously Hypertensive Rats Even in Low Doses

Nutrients ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 213 ◽  
Author(s):  
Iveta Najmanová ◽  
Jana Pourová ◽  
Přemysl Mladěnka
Keyword(s):  
Blood Pressure ◽  
Spontaneously Hypertensive Rats ◽  
Antihypertensive Effect ◽  
Mechanisms Of Action ◽  
Low Doses ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Phenolic Metabolites ◽  
Arterial Blood ◽  
Biological Situation

Quercetin is proven to decrease arterial blood pressure when given orally. Its bioavailability is, however, low and, therefore, its metabolites could rather be responsible for this effect. In particular, the colonic metabolites of quercetin, 3,4-dihydroxyphenylacetic acid (DHPA), 4-methylcatechol (4MC), and 3-(3-hydroxyphenyl)propionic acid (3HPPA), have been previously shown to decrease the blood pressure in spontaneously hypertensive rats (SHR). Interestingly, the mechanisms of action of these three metabolites are different. The aim of this study is hence to investigate if these metabolites can potentiate each other and thus decrease blood pressure in reduced doses. Three double-combinations of previously mentioned metabolites were administered to SHR as infusions to mimic a real biological situation. All combinations significantly decreased the blood pressure in SHR but there were important differences. The effect of DHPA and 4MC was mild and very short. A combination of DHPA with 3HPPA caused more pronounced effects, which were also rather short-lived. The last combination of 3HPPA and 4MC caused a long-lasting effect. In conclusion, certain combinations of quercetin metabolites have a more pronounced antihypertensive effect than single metabolites.

scholarly journals The blood pressure effect and related plasma levels of flavan-3-ols in spontaneously hypertensive rats

2015 ◽  
Vol 6 (11) ◽  
pp. 3479-3489 ◽  
Author(s):  
Mar Quiñones ◽  
Maria Margalef ◽  
Anna Arola-Arnal ◽  
Begoña Muguerza ◽  
Marta Miguel ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Plasma Levels ◽  
Spontaneously Hypertensive Rats ◽  
Antihypertensive Effect ◽  
Pressure Effect ◽  
Hypertensive Rats ◽  
Short Term ◽  
Spontaneously Hypertensive ◽  
Blood Pressure Effect

We studied the short-term antihypertensive effect of flavan-3-ols (−)-epicatechin, (+)-catechin and (−)-catechin, in spontaneously hypertensive rats (SHR).

Sign in / Sign up

Export Citation Format

Share Document