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 ◽  
...  

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

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Chen Su-Hong ◽  
Chen Qi ◽  
Li Bo ◽  
Gao Jian-Li ◽  
Su Jie ◽  
...  

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.


Hypertension ◽  
2000 ◽  
Vol 36 (suppl_1) ◽  
pp. 686-686
Author(s):  
Rodney J Bolterman ◽  
Clara M Ortiz-Ruiz ◽  
Luis A Juncos ◽  
Jane F Reckelhoff ◽  
Juan C Romero

48 Spontaneously hypertensive rats (SHR) reportedly have inappropriately high levels of Ang II despite normal plasma renin activity (PRA). Because Ang II stimulates oxidative stress, which in turn quenches nitric oxide, it is possible that Ang II-induced increases in oxidative stress contribute to the increase in blood pressure. Indeed, administering either a converting enzyme inhibitor (to decrease Ang II) or Tempol (a potent antioxidant) reduces blood pressure in SHR. We tested whether decreasing Ang II with a converting enzyme inhibitor reduces oxidative stress as well as MAP in SHR. For this, we divided 12 weeks old SHR into two groups (n=5 each). One group was treated with captopril (100 mg/kg/day added to the drinking water) and the other served as our untreated time controls. After 16 days of treatment, the rats were anesthetised and we measured MAP and collected blood samples to determine PRA, and the plasma levels of Ang II and thiobarbituric acid-reactive substances (TBARS). The captopril-treated rats had a lower MAP than the untreated rats (92±4 vs. 160±5 mmHg, respectively) and an increased PRA (42±1 vs. 26±6 ng/ml/h; captopril-treated vs. untreated rats, respectively). The decreased MAP in the captopril-treated SHR was accompanied by reduced plasma levels of Ang II (630±47 vs. 836±205 pg/ml) and TBARS (5.4±1.0 vs. 3.0±0.2 nmol/ml). Despite the significant decrease in Ang II levels in the captopril-treated SHR, they are still 20-fold higher rhan in normotensive Sprague-Dawley rats (34.0±8.8 pg/ml). In summary, captopril-induced decreases of MAP in SHR are accompanied not only by reduced levels of Ang II, but also by reduced oxidative stress. Because antioxidants also lower MAP in SHR, it suggests that oxidative stress induced by Ang II may play a role in the pathogenesis of the increased blood pressure in SHR.


1981 ◽  
Vol 61 (s7) ◽  
pp. 343s-345s ◽  
Author(s):  
J. S. Hutchinson ◽  
R. Di Nicolantonio ◽  
A. Lim ◽  
J. Clements ◽  
J. W. Funder

1. Immunoreactive β-endorphin (IR-βEP) was two- to three-fold higher in pituitary neuro-intermediate lobes (N-IL) of spontaneously hypertensive rats (SHR) than of normotensive Wistar—Kyoto (NT-WKY) controls. 2. Plasma levels of IR-βEP were lower in SHR than in NT-WKY rats. 3. Intravenous injections of morphine lowered blood pressure of both SHR and NT-WKY rats to the same level; naloxone restored blood pressure of both groups to pre-morphine values. 4. Infusion of bromocriptine in SHR for 1 week lowered blood pressure and N-IL IR-βEP concentration. 5. These results confirm and extend postulated dopaminergic defect in this model of hypertension.


1981 ◽  
Vol 59 (11) ◽  
pp. 1111-1116 ◽  
Author(s):  
Gary L. Wright

Experiments were conducted to examine the effects of plasma from spontaneously hypertensive rats (systolic blood pressure (SBP) = 183 torr; 1 torr = 133.322 Pa) on the contractile properties of aortic strips from normotensive rats. While incubated in plasma from spontaneously hypertensive (SH) rats, the aortic strips of normotensive rats exhibited hyperresponsiveness to norepinephrine (NE) compared with those incubated in plasma obtained from Wistar–Kyoto (SBP = 128 torr) or Sprague–Dawley (SBP = 110 torr) rats. The washout of plasma and perfusion of the aortic strips with Krebs bicarbonate solution abolished the effect of SH plasma on the reactivity to NE but not potassium, suggesting a residual hypersensitivity. The comparison of these findings with results obtained for contractions of aortic strips in Krebs bicarbonate solution containing high and low levels of calcium indicated the effect of SH plasma on vascular tissue sensitivity was not directly related to an alteration in plasma levels of calcium.


2012 ◽  
Vol 90 (2) ◽  
pp. 201-208 ◽  
Author(s):  
Clévia Santos Passos ◽  
Lucimeire Nova Carvalho ◽  
Roberto Braz Pontes ◽  
Ruy Ribeiro Campos ◽  
Olinda Ikuta ◽  
...  

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.


Nutrients ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 213 ◽  
Author(s):  
Iveta Najmanová ◽  
Jana Pourová ◽  
Přemysl Mladěnka

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.


1997 ◽  
Vol 25 (01) ◽  
pp. 21-26 ◽  
Author(s):  
Ho Sub Lee ◽  
Yun Cho Yu ◽  
Seong Tae Kim ◽  
Kyung Sik Kim

The aim of this study was to investigate the effects of moxibustion at the meridian points BL-15 (Xin-shu) and BL-27 (Xiao-chang-shu) on renal function, systolic blood pressure, plasma levels of renin activity, aldosterone and atrial natriuretic peptide in spontaneously hypertensive rats. The results showed that urine volume increased significantly after moxibustion at the meridian points BL-15, but decreased at BL-27. Urinary excretion of Na + decreased after moxibustion at the meridian points BL-15 and BL-27. Systolic blood pressure decreased after moxibustion at the meridian point BL-15. No effect was observed at BL-27. Plasma levels of aldosterone and renin activity increased significantly, but the levels of atrial natriuretic peptide decreased significantly after moxibustion at BL-15. Plasma levels of aldosterone and atrial natriuretic peptide increased significantly after moxibustion at the meridian points BL-27. These results suggest that the meridian points BL-15 and BL-27 are related to the regulation of renal function and the secretion of hormone with body fluid metabolism.


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