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 Antihypertensive Effect Of Magnesium Sulfate (Cormagnesin®) And Its Combination With Furosemide On Conscious Spontaneously Hypertensive Rats

2015 ◽  
Vol 8 (2) ◽  
pp. 112-117
Author(s):  
Katerina D. Simeonova ◽  
Krassimir D. Dimitrov ◽  
Nikolay D. Danchev
Keyword(s):  
Blood Pressure ◽  
Magnesium Sulfate ◽  
Spontaneously Hypertensive Rats ◽  
Antihypertensive Effect ◽  
Hypotensive Effect ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Arterial Blood ◽  
Significant Difference ◽  
Dose Dependent

SummaryThe present study demonstrates the antihypertensive effect of magnesium sulfate (Cormagnesin®) and its combination with Furosemide on conscious spontaneously hypertensive rats (SHR) after intravenous infusion. Experiments were carried out on six groups of conscious male SHR (n=6). Under short anesthesia the rats were chronically instrumented for intravenous (i.v.) drug administration. The arterial blood pressure (AP) was measured by indirect tale method. Cormagnesin®was applied by i.v. infusion in doses of 5, 20 and 40 mg/kg; and furosemide (10 mg/kg) was applied intraperitoneally. Experimental results showed significant decrease of AP after i.v. infusion of 20 mg/kg Cormagnesin®as well as after application of the Cormagnesin®and furosemide combination. The hypotensive effects of 40 mg/kg Cormagnesin®and of furosemide were not significant. There was no significant difference between the antihypertensive effects of Cormagnesin®and its combination with furosemide but the combination showed much better hypotensive effect than Furosemide (p<0.05). Our study demonstrated the antihypertensive effect of magnesium sulfate on conscious SHR after i.v. application. Our results suggest that the antihypertensive effect of magnesium sulfate in the doses applied is not dose-dependent. Magnesium sulfate potentiates the antihypertensive effect of furosemide in SHR.

scholarly journals Effects of Diabetic Hyperglycemia on Central Ang-(1-7)-Mas-R-nNOS Pathways in Spontaneously Hypertensive Rats

2016 ◽  
Vol 40 (5) ◽  
pp. 1186-1197 ◽  
Author(s):  
He Li ◽  
Xian Liu ◽  
Zhongqiao Ren ◽  
Jinxia Gu ◽  
Yingjie Lu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Blood Pressure ◽  
Cerebral Cortex ◽  
Spontaneously Hypertensive Rats ◽  
Hypertensive Rats ◽  
Systemic Injection ◽  
Spontaneously Hypertensive ◽  
Arterial Blood ◽  
Cerebrovascular Dysfunction ◽  
And Control

Background/Aims: Hypertension is a major cause of stroke, and diabetes can increase incidence of this disease. We determined the role played by central angiotensin-(1-7) [Ang-(1-7)] pathway in modulating spontaneously hypertension with diabetic hyperglycemia. Methods: Western Blot analysis and ELISA were used to determine the protein expression of Ang-(1-7) and its signal pathway Mas-R-nNOS in the cerebral cortex and hippocampus of spontaneously hypertensive rats (SHR) and control animals. In a subset of animals, diabetic hyperglycemia was induced by systemic injection of streptozotocin (STZ). We analyzed a relationship between the levels of central Ang-(1-7) and plasma brain natriuretic peptide (BNP) indicating a risk of ischemic stroke. We further examined the effects of Ang-(1-7) on arterial blood pressure. Results: Our findings demonstrated for the first time that administration of STZ 1) attenuates the levels of Ang-(1-7) in the cerebral cortex and hippocampus, which are closely linked to plasma BNP; and 2) leads to downregulation of central Ang-(1-7)-Mas-R-nNOS pathways. Notably, STZ has greater effects in SHR. Additionally, inhibition of oxidative stress can largely improve downregulation of Ang-(1-7) in diabetic SHR. Moreover, central stimulation of Ang-(1-7) pathway or a blockade of oxidative stress improves systolic blood pressure in diabetic SHR. Conclusions: The Ang-(1-7) signaling pathway is engaged in the adaptive mechanisms associated with diabetic hypertension, suggesting that enhancing Ang-(1-7)-Mas-R-nNOS system is likely to be beneficial in preventing against cardiovascular and cerebrovascular dysfunction and vulnerability related to spontaneously hypertension, particularly to diabetic hypertension.

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.

Tubuloglomerular feedback and autoregulation in spontaneously hypertensive rats

1990 ◽  
Vol 258 (6) ◽  
pp. F1479-F1489 ◽  
Author(s):  
F. H. Daniels ◽  
W. J. Arendshorst ◽  
R. G. Roberds
Keyword(s):  
Blood Pressure ◽  
Arterial Blood Pressure ◽  
Ureteral Obstruction ◽  
Spontaneously Hypertensive Rats ◽  
Control Period ◽  
Tubuloglomerular Feedback ◽  
Hypertensive Rats ◽  
Two Phase ◽  
Spontaneously Hypertensive ◽  
Arterial Blood

Experiments were conducted in 8-wk-old spontaneously hypertensive rats to determine whether tubuloglomerular feedback is essential for the autoregulation of renal blood flow. Autoregulation curves were obtained by measuring mean renal arterial blood pressure and flow during graded aortic occlusion. Renal vascular admittance was calculated from recordings of pulsatile renal arterial blood pressure and flow during induced atrial fibrillation. After a control period, acute ureteral obstruction was used to suppress tubuloglomerular feedback, as confirmed by measuring stop-flow pressure responses to rapid perfusion of Henle's loop. Ureteral obstruction did not impair steady-state autoregulation. During both the control and obstruction periods, the admittance gain was less than 1 at frequencies below 0.2 Hz, indicating dynamic autoregulatory activity. The control admittance contained two gain shoulders and two phase maxima, suggesting the presence of two control systems with response half-times of 1 and 10 s. During ureteral obstruction, the low-frequency shoulder and maximum disappeared, indicating that the slower system was no longer active. However, the high-frequency shoulder and maximum persisted, suggesting continued activity of the faster system. Collectively, these observations indicate the existence of a rapidly acting intrarenal control mechanism, in young spontaneously hypertensive rats, that may provide efficient autoregulation without assistance from tubuloglomerular feedback.

scholarly journals Hypotensive and Bradycardic Effects of Quinovic Acid Glycosides from Aspidosperma fendleri in Spontaneously Hypertensive Rats

2015 ◽  
Vol 10 (2) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Omar Estrada ◽  
Juan M. González-Guzmán ◽  
María M. Salazar-Bookman ◽  
Alfonso Cardozo ◽  
Eva Lucena ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Arterial Blood Pressure ◽  
Mean Arterial Blood Pressure ◽  
Spontaneously Hypertensive Rats ◽  
Cardiovascular Effects ◽  
Hypertensive Rats ◽  
Triterpenoid Saponins ◽  
Spontaneously Hypertensive ◽  
Arterial Blood

The Aspidosperma genus (Apocynaceae) represents one of the largest sources of indole alkaloids widely associated with cardiovascular effects. Aspidosperma fendleri, a plant found mainly in Venezuela, has a single phytochemical report in which is revealed the presence of alkaloids in its seeds. This study explored the cardiovascular effects of an ethanolic extract of A. fendleri leaves (EEAF) in spontaneously hypertensive rats (SHR) and its potential bioactive compounds. Using bioguided fractionation, fractions and pure compounds were intravenously administered to SHR and their effects on mean arterial blood pressure (MABP) and heart rate (HR) monitored over time. EEAF induced hypotensive and bradycardic effects as shown by significant reductions in mean arterial blood pressure (MABP) and heart rate (HR), respectively. Bioactivity-guided fractionation led to the isolation of a mixture of two known isomeric triterpenoid glycosides identified by spectral evidence as quinovic acid 3- O-β-rhamnopyranoside and quinovic acid 3- O-β-fucopyranoside. This mixture of triterpenoid saponins induced reductions in MABP and HR similar to those induced by propranolol. Together, these findings indicate that the two quinovic acid glycosides are responsible for the hypotensive and bradycardic effects which suggest their potential use in cardiovascular therapy.

scholarly journals Long-Term Effect of an AqueousFraxinus excelsiorL. Seed Extract in Spontaneously Hypertensive Rats

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Noemi López-Carreras ◽  
Sandra Fernández-Vallinas ◽  
Marta Miguel ◽  
Amaya Aleixandre
Keyword(s):  
Blood Pressure ◽  
Body Weight ◽  
Spontaneously Hypertensive Rats ◽  
Seed Extract ◽  
The Body ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Arterial Blood ◽  
Plasma Antioxidant Capacity

The effect of long-term intake of different doses (20, 40, and 60 mg/kg/day) of aFraxinus excelsiorL. seed extract (FESE) on spontaneously hypertensive rats (SHR) was evaluated. Water was used as control and captopril (50 mg/kg/day) was used as positive control. Systolic blood pressure, body weight, and food and liquid intake were registered weekly in SHR. The antioxidant and vascular relaxing properties of FESE were also studied in these animals. The development of hypertension was attenuated in the groups treated with captopril or FESE. The antihypertensive effect was more accentuated in the captopril group than in the FESE groups, and it was paradoxically more accentuated in the groups treated with 20 mg/kg/day or 40 mg/kg/day of FESE than in the group treated with the highest dose of this extract. Body weight gain and food intake increased in the FESE groups. After removing the corresponding antihypertensive treatment, the arterial blood pressure and the body weight of the FESE treated animals returned to control values. In addition, FESE increased plasma antioxidant capacity and decreased plasma and liver malondialdehyde levels. Moreover, acetylcholine relaxation improved in the aorta rings from the FESE treated rats.

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