scholarly journals The Vasoactive Mas Receptor in Essential Hypertension

2020 ◽  
Vol 9 (1) ◽  
pp. 267 ◽  
Author(s):  
Amalie Povlsen ◽  
Daniela Grimm ◽  
Markus Wehland ◽  
Manfred Infanger ◽  
Marcus Krüger
Keyword(s):  
Essential Hypertension ◽  
Angiotensin Ii ◽  
Angiotensin Converting Enzyme ◽  
Current Knowledge ◽  
Converting Enzyme ◽  
Angiotensin Ii Receptor ◽  
Vascular Control ◽  
Renin Angiotensin ◽  
Mas Receptor ◽  
Clinical Potential

The renin–angiotensin–aldosterone system (RAAS) has been studied extensively, and with the inclusion of novel components, it has become evident that the system is much more complex than originally anticipated. According to current knowledge, there are two main axes of the RAAS, which counteract each other in terms of vascular control: The classical vasoconstrictive axis, renin/angiotensin-converting enzyme/angiotensin II/angiotensin II receptor type 1 (AT1R), and the opposing vasorelaxant axis, angiotensin-converting enzyme 2/angiotensin-(1-7)/Mas receptor (MasR). An abnormal activity within the system constitutes a hallmark in hypertension, which is a global health problem that predisposes cardiovascular and renal morbidities. In particular, essential hypertension predominates in the hypertensive population of more than 1.3 billion humans worldwide, and yet, the pathophysiology behind this multifactorial condition needs clarification. While commonly applied pharmacological strategies target the classical axis of the RAAS, discovery of the vasoprotective effects of the opposing, vasorelaxant axis has presented encouraging experimental evidence for a new potential direction in RAAS-targeted therapy based on the G protein-coupled MasR. In addition, the endogenous MasR agonist angiotensin-(1-7), peptide analogues, and related molecules have become the subject of recent studies within this field. Nevertheless, the clinical potential of MasR remains unclear due to indications of physiological-biased activities of the RAAS and interacting signaling pathways.

scholarly journals Renin-angiotensin-aldosterone system inhibitors – a realm of confusion in COVID-19

2021 ◽  
Vol 4 (Special2) ◽  
pp. 389-394
Author(s):  
Angela Madalina Lazar
Keyword(s):  
Angiotensin Ii ◽  
Angiotensin Converting Enzyme ◽  
Current Knowledge ◽  
Angiotensin Receptor Blockers ◽  
Protective Effects ◽  
Converting Enzyme ◽  
Angiotensin I ◽  
Renin Angiotensin Aldosterone System ◽  
Renin Angiotensin ◽  
Raas Inhibitors

Currently, there is a persisting dispute regarding the renin-angiotensin-aldosterone-system (RAAS) inhibitors' safety of use in COVID-19 pandemics. On one side, RAAS inhibitors appear to determine an overexpression of ACE2, the receptor of SARS-CoV-2. Therefore, they could increase the risk of SARS-CoV-2 infection and its degree of severity. On the other side, the discontinuation of RAAS leads to cardiovascular decompensation and has been discouraged by the major medical societies. Also, large-cohort studies report beneficial or at least neutral effects for the RAAS inhibitors in COVID-19 patients. Worldwide, millions of patients receive RAAS inhibitors for the treatment of hypertension and other important comorbidities. In this context, knowledge of the exact effect of these medications becomes of crucial significance. This paper aims to fill in a gap in the current knowledge and presents a putative mechanism by which RAAS inhibitor administration's beneficial results can be explained better. RAAS inhibitors can be beneficial, as they counteract the excessive detrimental activation of the classical angiotensin-converting enzyme (ACE) axis, decreasing the angiotensin II levels. The angiotensin receptor blockers (ARBs) increase the angiotensin II levels, while the angiotensin-converting enzyme inhibitors (ACEI) increase the angiotensin I levels; these substrates will compete with the SARS-CoV-2 for the ACE2 binding, decreasing the viral infectivity. In addition, following the RAAS inhibitors treatment, the up-regulated ACE2 will cleave these substrates (angiotensin I and II), particularly to angiotensin 1-7 that possesses vasodilator, protective effects.

scholarly journals Local Angiotensin-Converting Enzyme 2 Gene Expression in Kidney Allografts Is Not Affected by Renin-Angiotensin-Aldosterone Inhibitors

2021 ◽  
Vol 46 (2) ◽  
pp. 245-249
Author(s):  
Monika Cahova ◽  
Martin Kveton ◽  
Vojtech Petr ◽  
David Funda ◽  
Helena Dankova ◽  
...  
Keyword(s):  
Angiotensin Converting Enzyme ◽  
Kidney Transplant ◽  
Converting Enzyme ◽  
Transplant Recipients ◽  
Angiotensin Ii Receptor ◽  
Kidney Transplant Recipients ◽  
Angiotensin Converting Enzyme 2 ◽  
Renin Angiotensin ◽  
Receptor Blockers

<b><i>Background:</i></b> Preclinical studies suggested that pharmacological inhibition of the renin-angiotensin-aldosterone system (RAAS) by ACE inhibitors (ACEis) or angiotensin II receptor blockers (ARBs) may increase local angiotensin-converting enzyme 2 (<i>ACE2</i>) expression. <b><i>Methods:</i></b> In this study, we evaluated the effect of ACEi or ARB treatment on expression of <i>ACE2</i>, <i>ACE</i>, and <i>AGTR1</i> in 3-month protocol kidney allograft biopsies of stable patients using RT-qPCR (<i>n</i> = 48). Protein ACE2 expression was assessed using immunohistochemistry from paraffin sections. <b><i>Results:</i></b> The therapy with RAAS blockers was not associated with increased <i>ACE2, ACE</i>, or <i>ATGR1</i> expression in kidney allografts and also ACE2 protein immunohistochemistry did not reveal differences among groups. <b><i>Conclusions:</i></b> ACEis or ARBs in kidney transplant recipients do not affect local ACE2 expression. This observation supports long-term RAAS treatment in kidney transplant recipients, despite acute complications such as COVID-19 where ACE2 serves as the entry protein for infection.

Comparative effects of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers on pulmonary function in hypertensive patients

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Azza S. Jabbar ◽  
Nadheera F. Neamah ◽  
Ahmed H. Al-Darraji
Keyword(s):  
Angiotensin Ii ◽  
Adverse Effects ◽  
Angiotensin Converting Enzyme ◽  
Enzyme Inhibitors ◽  
Angiotensin Converting Enzyme Inhibitors ◽  
Converting Enzyme ◽  
Angiotensin Ii Receptor ◽  
Converting Enzyme Inhibitors ◽  
Hypertensive Patients ◽  
Receptor Blockers

Abstract Objectives Hypertension is a very common cardiovascular disease. Angiotensin-converting enzyme inhibitors (ACEi) and angiotensin II receptor blockers (ARBs) are widely used to treat hypertension. Many patients with hypertension are vulnerable to the antihypertensive adverse effects, which potentially reduces the adherence rate. Therefore, we conducted this study in order to evaluate the safety profile of both classes (ACEi and ARBs) on respiratory functions. Methods Two main groups of subjects were studied: first group is healthy control subjects and the second group is hypertensive patients, which was subdivided into subgroups in order to investigate the effect of all tested medications (captopril, enalapril, lisinopril, losartan, and valsartan). Respiratory efficiency was evaluated by measuring pulmonary function tests: FEV1, FVC, and FEV1%. Measurements were done using micromedical spirometer. Results We found that ARBs do not impair normal respiratory functions as measured by FEV1, FEV1%, and FVC in hypertensive patients. While ACEi treatments significantly reduced FEV1, FEV1%, and FVC compared to the other groups. Conclusions ARBs are not associated with any harmful effects on respiratory functions in hypertensive patients, unlike ACEi. As such, they could represent a first-choice treatment for hypertensive patients who are at high risk to the respiratory adverse effects.

scholarly journals Pathological Role of Angiotensin II in Severe COVID-19

TH Open ◽  
2020 ◽  
Vol 04 (02) ◽  
pp. e138-e144 ◽  
Author(s):  
Wolfgang Miesbach
Keyword(s):  
Angiotensin Ii ◽  
Angiotensin Converting Enzyme ◽  
Treatment Options ◽  
Renin Angiotensin System ◽  
Target Cells ◽  
Converting Enzyme ◽  
Angiotensin System ◽  
Angiotensin Converting Enzyme 2 ◽  
Renin Angiotensin ◽  
Novel Coronavirus

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.

Resveratrol ameliorates the cyclosporine-induced vascular and renal impairments: possible impact of the modulation of renin–angiotensin system

2019 ◽  
Vol 97 (12) ◽  
pp. 1115-1123 ◽  
Author(s):  
Seldag Bekpinar ◽  
Ece Karaca ◽  
Selin Yamakoğlu ◽  
F. İlkay Alp-Yıldırım ◽  
Vakur Olgac ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Angiotensin Converting Enzyme ◽  
Renin Angiotensin System ◽  
Immunosuppressive Drug ◽  
Oxidative Stress Marker ◽  
Converting Enzyme ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
System Components ◽  
Renal Tubular

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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