Effects of angiotensin II on the spontaneous activity of rostral ventrolateral medullary cardiovascular neurons and blood pressure in spontaneously hypertensive rats

1996 ◽  
Vol 3 (3) ◽  
pp. 191-202 ◽  
Author(s):  
R. K. W. Chan ◽  
Y. S. Chan ◽  
T. M. Wong
Keyword(s):  
Blood Pressure ◽  
Angiotensin Ii ◽  
Spontaneous Activity ◽  
Spontaneously Hypertensive Rats ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Cardiovascular Neurons

scholarly journals Black Soybean and Adzuki Bean Extracts Lower Blood Pressure by Modulating the Renin-Angiotensin System in Spontaneously Hypertensive Rats

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1571
Author(s):  
Eun-Woo Jeong ◽  
Se-Yeong Park ◽  
Yun-Sun Yang ◽  
Youjin Baek ◽  
Damin Yun ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Angiotensin Ii ◽  
Spontaneously Hypertensive Rats ◽  
Renin Angiotensin System ◽  
Adzuki Bean ◽  
Hypertensive Rats ◽  
Angiotensin System ◽  
Spontaneously Hypertensive ◽  
Black Soybean ◽  
Renin Angiotensin

Hypertension, causing cardiovascular disease, stroke, and heart failure, has been a rising health issue worldwide. Black soybeans and adzuki beans have been widely consumed throughout history due to various bioactive components. We evaluated the antihypertensive effects of black soybean and adzuki bean ethanol extracts on blood pressure, renin-angiotensin system (RAS), and aortic lesion in spontaneously hypertensive rats. A group of WKY (normal) and six groups of spontaneously hypertensive rats were administered with saline (SHR), 50 mg/kg of captopril (CAP), 250 and 500 mg/kg of black soybean extracts (BE250 and BE500), 250 and 500 mg/kg of adzuki bean extracts (AE250 and AE500) for eight weeks. BE250, BE500, AE250, and AE500 significantly (p < 0.05) reduced relative liver weight, AST, ALT, triglyceride, total cholesterol, systolic blood pressure, and angiotensin-converting-enzyme level compared to SHR. The angiotensin II level in AE500 and renin mRNA expression in BE500 and AE500 were significantly (p < 0.05) decreased compared to SHR. The lumen diameter was significantly (p < 0.05) reduced in only CAP. Furthermore, systolic and diastolic blood pressure and angiotensin II level in AE500 were lower than those of BE500. These results suggest that AE exhibit more antihypertensive potential than BE in spontaneously hypertensive rats.

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.

The Intrinsic Brain Iso-Renin-Angiotensin System in the Rat: Its Possible Role in Central Mechanisms of Blood Pressure Regulation

1974 ◽  
Vol 48 (s2) ◽  
pp. 265s-268s ◽  
Author(s):  
D. Ganten ◽  
J. S. Hutchinson ◽  
P. Schelling
Keyword(s):  
Blood Pressure ◽  
Cerebrospinal Fluid ◽  
Angiotensin Ii ◽  
Spontaneously Hypertensive Rats ◽  
Renin Angiotensin System ◽  
Angiotensin Ii Receptor ◽  
Hypertensive Rats ◽  
Angiotensin System ◽  
Spontaneously Hypertensive ◽  
Renin Angiotensin

1. Angiotensin is produced by the intrinsic iso-renin-angiotensin system. 2. Angiotensin is secreted into the cerebrospinal fluid of nephrectomized rats. 3. Angiotensin in cerebrospinal fluid elevates systemic blood pressure. 4. Rats with hereditary diabetes insipidus are virtually non-responsive to intraventricular angiotensin. 5. Angiotensin II is elevated in the cerebrospinal fluid of spontaneously hypertensive rats. 6. An intraventricular perfusion of the angiotensin II receptor-blocking agent P 113 decreases blood pressure in spontaneously hypertensive rats.

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