scholarly journals Antihypertensive Activity of Eucommia Ulmoides Oliv: Male Flower Extract in Spontaneously Hypertensive Rats

2020 ◽  
Vol 2020 ◽  
pp. 1-6 ◽  
Author(s):  
Zhen-Jiang Ding ◽  
Chao Liang ◽  
Xiao Wang ◽  
Xin Yao ◽  
Ruo-Han Yang ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Aqueous Extract ◽  
Spontaneously Hypertensive Rats ◽  
Male Flower ◽  
Antihypertensive Activity ◽  
Eucommia Ulmoides ◽  
Ang Ii ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Male Flowers

Eucommia ulmoides Oliv. is a traditional medical plant in Asia; however, it is still unknown whether Eucommia male flowers have an antihypertensive activity. In this study, we found that the aqueous extract of Eucommia ulmoides Oliv. male flowers can lower the blood pressure of SHR in a dose-dependent manner. Mechanistic studies suggested that the aqueous extract of male flowers can promote the mRNA and protein expressions of ACE2 in the kidney of SHR. ELISA assay showed that the plasma levels of ANG II was decreased, while ANG-(1–7) was increased in SHR treated with the aqueous extract of male flowers. ACE2 inhibitor DX600 can reverse the aqueous extract of Eucommia ulmoides Oliv. male flower-induced downregulation of Ang II and upregulation of Ang-(1–7), as well as the reduction of blood pressure in SHR. Moreover, Ang-(1–7)-Mas receptor antagonist A-779 abolished the antihypertensive effects of the aqueous extract of Eucommia ulmoides Oliv. male flower in SHR. The aqueous extract of Eucommia ulmoides Oliv. male flowers exhibited an antihypertensive action through the activation of ACE2-Ang-(1–7)-Mas signaling pathways in spontaneously hypertensive rats.

scholarly journals Piper sarmentosum Leaves Aqueous Extract Attenuates Vascular Endothelial Dysfunction in Spontaneously Hypertensive Rats

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Fatimatuzzahra Hashim Fauzy ◽  
Maizura Mohd Zainudin ◽  
Hidayatul Radziah Ismawi ◽  
Taher F. T. Elshami
Keyword(s):  
Blood Pressure ◽  
Aqueous Extract ◽  
Spontaneously Hypertensive Rats ◽  
Positive Control ◽  
No Production ◽  
Hypertensive Rats ◽  
Traditional Use ◽  
Spontaneously Hypertensive ◽  
Treatment Groups ◽  
Endothelin System

Piper sarmentosum is a tropical plant in Southeast Asia known for its traditional use in curing various ailments including hypertension. Previous research works have provided evidence for the herb’s antihypertensive property. However, the exact mechanisms involved are still in question. The present study investigated the effects of Piper sarmentosum leaves aqueous extract (PSAE) treatment on vascular endothelin system in spontaneously hypertensive rats (SHRs). Four groups of SHRs were treated for 28 consecutive days, with negative and positive control groups receiving distilled water and 3 mg/kg perindopril, respectively. Another two groups are the treatment groups, which received PSAE and combination of 1.5 mg/kg perindopril and PSAE. Weekly measurements of blood pressure showed that PSAE significantly reduced the systolic, diastolic, and mean arterial pressures (P<0.05) of the rats. PSAE also increased mesenteric artery nitric oxide (NO) level (P<0.05) and reduced endothelin-1 (ET-1) level (P<0.05) in the treatment groups. Our results demonstrate that oral administration of PSAE reduced blood pressure in SHRs by reducing the ET-1 level while increasing NO production.

The Relationship Between Angiotensin II (ANG II) and Oxidative Stress in the Maintenance of Mean Arterial Pressure (MAP) of Spontaneously Hypertensive Rats.

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
Keyword(s):  
Oxidative Stress ◽  
Blood Pressure ◽  
Plasma Levels ◽  
Spontaneously Hypertensive Rats ◽  
Enzyme Inhibitor ◽  
Ang Ii ◽  
Converting Enzyme ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Converting Enzyme Inhibitor

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.

Antihypertensive actions of angiotensin-(1-7) in spontaneously hypertensive rats

1995 ◽  
Vol 269 (1) ◽  
pp. H313-H319 ◽  
Author(s):  
I. F. Benter ◽  
C. M. Ferrario ◽  
M. Morris ◽  
D. I. Diz
Keyword(s):  
Blood Pressure ◽  
Prostaglandin E2 ◽  
Spontaneously Hypertensive Rats ◽  
Systolic Pressure ◽  
Experimental Hypertension ◽  
Electrolyte Balance ◽  
Ang Ii ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Plasma Vasopressin

Observations that angiotensin-(1-7) [ANG-(1-7)] may oppose the vasoconstrictor actions of angiotensin II (ANG II) prompted an investigation of the effects of the heptapeptide on the maintenance of elevated blood pressure in spontaneously hypertensive rats (SHR). ANG-(1-7) (24 micrograms.kg-1.h-1) was infused into the jugular vein of 13-wk-old SHR (n = 64), Wistar-Kyoto (WKY, n = 50), and Sprague-Dawley (SD, n = 18) rats for 2 wk, with the use of osmotic minipumps. Blood pressure, fluid and electrolyte balance, plasma vasopressin, and urinary excretion of prostaglandin E2 and 6-ketoprostaglandin F1 alpha (6-keto-PGF1 alpha) were measured at days 2, 7, and 12 of the infusion. In SHR, ANG-(1-7) caused a sustained and significant reduction in plasma vasopressin concentration that was associated with an increase in urinary prostaglandin E2 and 6-keto-PGF1 alpha excretion at day 2 after the commencement of the infusion. These changes were accompanied by diuresis and natriuresis during the first 3 days of infusion in SHR but not in WKY or SD rats. Direct measurements of arterial pressure confirmed the lowering effect of ANG-(1-7) on systolic pressure of SHR on day 2 of treatment with a restoration of the pressure by days 7 and 12. These findings, along with our previous demonstration that ANG-(1-7) is an active depressor peptide in the intact animal, suggest that ANG-(1-7) may play a significant role as a vasodepressor system opposing the hemodynamic actions of ANG II in this genetic form of experimental hypertension.

Expression of smooth muscle MyHC B in blood vessels of hypertrophied heart in experimentally hypertensive rats

2003 ◽  
Vol 284 (2) ◽  
pp. R607-R610 ◽  
Author(s):  
Katharina Wetzel ◽  
Ovidiu Baltatu ◽  
Benno Nafz ◽  
Pontus B. Persson ◽  
Hannelore Haase ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Smooth Muscle ◽  
Adaptive Response ◽  
Spontaneously Hypertensive Rats ◽  
Expression Patterns ◽  
Ang Ii ◽  
Hypertensive Rats ◽  
Genetic Origin ◽  
Spontaneously Hypertensive ◽  
Muscle Myosin

We demonstrated recently a significantly lower fraction of cardiac precapillary arterioles that expressed smooth muscle myosin heavy chain (MyHC) B (SMB) in spontaneously hypertensive rats. To clarify whether this reduction of SMB expression is of genetic origin, we investigated SMB expression in cardiac precapillary arterioles of normotensive and experimentally hypertensive rats (one clip, one kidney or ANG II minipump). We observed similar SMB expression patterns in precapillary arterioles of experimentally hypertensive rats compared with normotensive controls. These observations suggest that the downregulation of SMB in spontaneously hypertensive rats is of genetic origin rather than an adaptive response to chronically enhanced blood pressure and cardiac hypertrophy.

scholarly journals Combined antihypertensive effect of unripe Rubus coreanus Miq. and Dendropanax morbiferus H. Lév. Extracts in 1 kidney-1 clip hypertensive rats and spontaneously hypertensive rats

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Soyi Park ◽  
Ki Hoon Lee ◽  
Hakjoon Choi ◽  
Goeun Jang ◽  
Wan Seok Kang ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Vascular Function ◽  
Spontaneously Hypertensive Rats ◽  
Antihypertensive Activity ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Rat Models ◽  
Rubus Coreanus ◽  
Hypertensive Rat

Abstract Background We previously showed that enzymatically hydrolyzed Dendropanax morbiferus H. Lév. leaf (Hy-DP) and unripe Rubus coreanus Miq. (5-uRCK) extracts exhibit potent vasodilator effects on isolated aortic rings from rats partly through endothelium-dependent and endothelium-independent mechanisms. These two extracts have different mechanisms of action; however, their combined effect on antihypertensive activity has not been explored. Methods The present study aims to investigate the effect of a chronic optimized mixture (HDR-2, composed of Hy-DP and 5-uRCK in a 2:1 mass ratio) on vascular tension and blood pressure in two different hypertensive rat models. Results The results showed that HDR-2 concentration-dependently relaxed endothelium-intact and endothelium-denuded aortic rings precontracted with phenylephrine. Antihypertensive effects were assessed in vivo on a 1 kidney-1 clip (1 K-1C) rat model of hypertension and spontaneously hypertensive rats (SHRs). Acute HDR-2 treatment significantly decreased systolic blood pressure (SBP) 3 h posttreatment in both models. Chronic HDR-2 administration also significantly decreased SBP in the hypertensive rat models. Moreover, HDR-2 increased eNOS protein expression and phosphorylation levels in the aorta. Conclusion Chronic HDR-2 administration may effectively improve vascular function by decreasing plasma angiotensin-converting enzyme (ACE) activity and AngII levels. HDR-2 significantly improved acetylcholine (ACh)-induced aortic endothelium-dependent relaxation and affected sodium nitroprusside (SNP)-induced endothelium-independent relaxation in SHRs.

Ventrolateral medulla in spontaneously hypertensive rats: role of angiotensin II

1993 ◽  
Vol 264 (2) ◽  
pp. R388-R395 ◽  
Author(s):  
H. Muratani ◽  
C. M. Ferrario ◽  
D. B. Averill
Keyword(s):  
Blood Pressure ◽  
Angiotensin Ii ◽  
Spontaneously Hypertensive Rats ◽  
Pressor Response ◽  
Ventrolateral Medulla ◽  
Ang Ii ◽  
Gamma Aminobutyric Acid ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Wky Rats

We investigated whether angiotensin II (ANG II), endogenous to the ventrolateral medulla (VLM), contributes to cardiovascular regulation in spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats. The action of ANG II endogenous to the VLM was examined by microinjection of 100 pmol of [Sar1,Thr8]ANG II into either the rostral (R) or caudal (C) VLM. This ANG II antagonist caused depressor and bradycardic responses in the RVLM and pressor and tachycardic responses in the CVLM. The magnitude of the blood pressure responses was significantly greater (P < 0.01 in RVLM and P < 0.05 in CVLM) in SHRs (-27 +/- 3 mmHg in RVLM and 29 +/- 4 mmHg in CVLM) than in WKY rats (-17 +/- 1 and 17 +/- 2 mmHg, respectively). Suppression of tonic activity of RVLM neurons by bilateral injection of muscimol in the RVLM showed that the pressor response produced by ANG II antagonist injection in the CVLM required the integrity of rostral pressor neurons. The present data suggest that ANG II endogenous to RVLM and CVLM acts as a tonic excitatory agent on vasomotor neurons of the VLM. The contribution of ANG II in the RVLM and CVLM to the prevailing level of blood pressure was significantly (P < 0.01) larger in SHRs vs. WKY rats when the effect of ANG II blockade was measured as the change in blood pressure. Blockade of gamma-aminobutyric acid (GABA)A receptors in the RVLM showed that inhibitory GABAergic input to the RVLM was not diminished in this strain.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Hypotensive and Angiotensin-Converting Enzyme Inhibitory Activities ofEisenia fetidaExtract in Spontaneously Hypertensive Rats

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Shumei Mao ◽  
Chengde Li
Keyword(s):  
Blood Pressure ◽  
Inhibitory Activity ◽  
Spontaneously Hypertensive Rats ◽  
Ang Ii ◽  
Shr Rats ◽  
Hypertensive Rats ◽  
Ace Inhibitory Activity ◽  
Spontaneously Hypertensive ◽  
Ace Inhibitory

Objectives. This study aimed to investigate the antihypertensive effects of anEisenia fetidaextract (EFE) and its possible mechanisms in spontaneously hypertensive rats (SHR rats).Methods. Sixteen-week-old SHR rats and Wistar-Kyoto rats (WKY rats) were used in this study. Rats were, respectively, given EFE (EFE group), captopril (captopril group), or phosphate-buffered saline (PBS) (normal control group and SHR group) for 4 weeks. ACE inhibitory activity of EFEin vitrowas determined. The systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured using a Rat Tail-Cuff Blood Pressure System. Levels of angiotensin II (Ang II), aldosterone (Ald), and 6-keto-prostaglandin F1 alpha (6-keto-PGF1α) in plasma were determined by radioimmunoassay, and serum nitric oxide (NO) concentration was measured by Griess reagent systems.Results. EFE had marked ACE inhibitory activityin vitro(IC50= 2.5 mg/mL). After the 4-week drug management, SHR rats in EFE group and in captopril group had lower SBP and DBP, lower levels of Ang II and Ald, and higher levels of 6-keto-PGF1αand NO than the SHR rats in SHR group.Conclusion. These results indicate that EFE has hypotensive effects in SHR rats and its effects might be associated with its ACE inhibitory activity.

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