scholarly journals Potassium Intake Prevents the Induction of the Renin-Angiotensin System and Increases Medullary ACE2 and COX-2 in the Kidneys of Angiotensin II-Dependent Hypertensive Rats

2019 ◽  
Vol 10 ◽  
Author(s):  
Alexis A. Gonzalez ◽  
Matias Gallardo ◽  
Carlos Cespedes ◽  
Carlos P. Vio
2004 ◽  
Vol 287 (1) ◽  
pp. H216-H224 ◽  
Author(s):  
Yasuo Kansui ◽  
Koji Fujii ◽  
Keiichiro Nakamura ◽  
Kenichi Goto ◽  
Hideyuki Oniki ◽  
...  

Blockade of the renin-angiotensin system improves the impaired endothelium-dependent relaxations associated with hypertension and aging, partly through amelioration of endothelium-derived hyperpolarizing factor (EDHF)-mediated responses. Although the nature of EDHF is still controversial, recent studies have suggested the involvement of gap junctions in EDHF-mediated responses. Gap junctions consist of connexins (Cx), and we therefore tested whether the expression of Cx in vascular endothelial cells would be altered by hypertension and antihypertensive treatment. Spontaneously hypertensive rats (SHR) were treated with either the angiotensin II type 1 receptor antagonist candesartan or the combination of hydralazine and hydrochlorothiazide for 3 mo from 5 to 8 mo of age. Confocal laser scanning microscopy after immunofluorescent labeling with antibodies against Cx37, Cx40, and Cx43 revealed that the expression of Cx37 and Cx40 in endothelial cells of the mesenteric artery was significantly lower in SHR than in WKY. Treatment with candesartan, but not the combination of hydralazine and hydrochlorothiazide, significantly increased the expression of Cx37 and Cx40, although blood pressure decreased similarly. On the other hand, the expression of Cx43, though scarce and heterogeneous, was increased in SHR compared with WKY, and candesartan treatment lowered the expression of Cx43. These findings suggest that renin-angiotensin system blockade corrects the decreased expression of Cx37 and Cx40 in arterial endothelial cells of hypertensive rats, partly independently of blood pressure, whereas the expression of Cx43 changed in the opposite direction. It remains to be clarified whether these changes in Cx37 and Cx40 are related to endothelial function, particularly that attributable to EDHF.


Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1571
Author(s):  
Eun-Woo Jeong ◽  
Se-Yeong Park ◽  
Yun-Sun Yang ◽  
Youjin Baek ◽  
Damin Yun ◽  
...  

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.


1974 ◽  
Vol 48 (s2) ◽  
pp. 265s-268s ◽  
Author(s):  
D. Ganten ◽  
J. S. Hutchinson ◽  
P. Schelling

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.


TH Open ◽  
2020 ◽  
Vol 04 (02) ◽  
pp. e138-e144 ◽  
Author(s):  
Wolfgang Miesbach

AbstractThe activated renin–angiotensin system induces a prothrombotic state resulting from the imbalance between coagulation and fibrinolysis. Angiotensin II is the central effector molecule of the activated renin–angiotensin system and is degraded by the angiotensin-converting enzyme 2 to angiotensin (1–7). The novel coronavirus infection (classified as COVID-19) is caused by the new coronavirus SARS-CoV-2 and is characterized by an exaggerated inflammatory response that can lead to severe manifestations such as acute respiratory distress syndrome, sepsis, and death in a proportion of patients, mostly elderly patients with preexisting comorbidities. SARS-CoV-2 uses the angiotensin-converting enzyme 2 receptor to enter the target cells, resulting in activation of the renin–angiotensin system. After downregulating the angiotensin-converting enzyme 2, the vasoconstrictor angiotensin II is increasingly produced and its counterregulating molecules angiotensin (1–7) reduced. Angiotensin II increases thrombin formation and impairs fibrinolysis. Elevated levels were strongly associated with viral load and lung injury in patients with severe COVID-19. Therefore, the complex clinical picture of patients with severe complications of COVID-19 is triggered by the various effects of highly expressed angiotensin II on vasculopathy, coagulopathy, and inflammation. Future treatment options should focus on blocking the thrombogenic and inflammatory properties of angiotensin II in COVID-19 patients.


1977 ◽  
Vol 232 (5) ◽  
pp. F434-F437 ◽  
Author(s):  
R. H. Freeman ◽  
J. O. Davis ◽  
W. S. Spielman

Suprarenal aortic constriction sufficient to reduce renal perfusion pressure by approximately 50% increased aldosterone secretion in anesthetized rats pretreated with dexamethasone. Bilateral nephrectomy under the same experimental conditions blocked the aldosterone response. Additionally, [1-sarcosine, 8-alanine]angiotensin II blocked the response in aldosterone secretion to aortic constriction in dexamethasone-treated rats. Finally, in rats hypophysectomized to exclude the influence of ACTH, the aldosterone response to aortic constriction was blocked by [1-sarcosine, 8-alanine]angiotensin II. The results indicate that angiotensin II increased aldosterone secretion during aortic constriction in the rat. These observations, along with those reported previously in sodium-depleted rats, point to an important overall role for the renin-angiotensin system in the control of aldosterone secretion in the rat.


2019 ◽  
Vol 97 (12) ◽  
pp. 1115-1123 ◽  
Author(s):  
Seldag Bekpinar ◽  
Ece Karaca ◽  
Selin Yamakoğlu ◽  
F. İlkay Alp-Yıldırım ◽  
Vakur Olgac ◽  
...  

Cyclosporine, an immunosuppressive drug, exhibits a toxic effect on renal and vascular systems. The present study investigated whether resveratrol treatment alleviates renal and vascular injury induced by cyclosporine. Cyclosporine (25 mg/kg per day, s.c.) was given for 7 days to rats either alone or in combination with resveratrol (10 mg/kg per day, i.p.). Relaxation and contraction responses of aorta were examined. Serum levels of blood urea nitrogen, creatinine, angiotensin II, and angiotensin 1-7 were measured. Histopathological examinations as well as immunostaining for 4-hydroxynonenal and nitrotyrosine were performed in the kidney. RNA expressions of renin–angiotensin system components were also measured in renal and aortic tissues. Cyclosporine decreased the endothelium-dependent relaxation and increased vascular contraction in the aorta. It caused renal tubular degeneration and increased immunostaining for 4-hydroxynonenal, an oxidative stress marker. Cyclosporine also caused upregulations of the vasoconstrictive renin–angiotensin system components in renal (angiotensin-converting enzyme) and aortic (angiotensin II type 1 receptor) tissues. Resveratrol co-treatment prevented the cyclosporine-related deteriorations. Moreover, it induced the expressions of vasodilatory effective angiotensin-converting enzyme 2 and angiotensin II type 2 receptor in aorta and kidney, respectively. We conclude that resveratrol may be effective in preventing cyclosporine-induced renal tubular degeneration and vascular dysfunction at least in part by modulating the renin–angiotensin system.


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