scholarly journals Nonclassical Axis of the Renin-Angiotensin System and Neprilysin: Key Mediators That Underlie the Cardioprotective Effect of PPAR-Alpha Activation during Myocardial Ischemia in a Metabolic Syndrome Model

PPAR Research ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
María Sánchez-Aguilar ◽  
Luz Ibarra-Lara ◽  
Leonardo del Valle-Mondragón ◽  
Elizabeth Soria-Castro ◽  
Juan Carlos Torres-Narváez ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Metabolic Syndrome ◽  
Myocardial Ischemia ◽  
Renin Angiotensin System ◽  
Converting Enzyme ◽  
Angiotensin Receptor ◽  
Ppar Alpha ◽  
Angiotensin Iv ◽  
Angiotensin System ◽  
Angiotensin Iii

The activation of the renin-angiotensin system (RAS) participates in the development of metabolic syndrome (MetS) and in heart failure. PPAR-alpha activation by fenofibrate reverts some of the effects caused by these pathologies. Recently, nonclassical RAS components have been implicated in the pathogenesis of hypertension and myocardial dysfunction; however, their cardiac functions are still controversial. We evaluated if the nonclassical RAS signaling pathways, directed by angiotensin III and angiotensin-(1-7), are involved in the cardioprotective effect of fenofibrate during ischemia in MetS rats. Control (CT) and MetS rats were divided into the following groups: (a) sham, (b) vehicle-treated myocardial infarction (MI-V), and (c) fenofibrate-treated myocardial infarction (MI-F). Angiotensin III and angiotensin IV levels and insulin increased the aminopeptidase (IRAP) expression and decreased the angiotensin-converting enzyme 2 (ACE2) expression in the hearts from MetS rats. Ischemia activated the angiotensin-converting enzyme (ACE)/angiotensin II/angiotensin receptor 1 (AT1R) and angiotensin III/angiotensin IV/angiotensin receptor 4 (AT4R)-IRAP axes. Fenofibrate treatment prevented the damage due to ischemia in MetS rats by favoring the angiotensin-(1-7)/angiotensin receptor 2 (AT2R) axis and inhibiting the angiotensin III/angiotensin IV/AT4R-IRAP signaling pathway. Additionally, fenofibrate downregulated neprilysin expression and increased bradykinin production. These effects of PPAR-alpha activation were accompanied by a reduction in the size of the myocardial infarct and in the activity of serum creatine kinase. Thus, the regulation of the nonclassical axis of RAS forms part of a novel protective effect of fenofibrate in myocardial ischemia.

Combination renin–angiotensin system blockade and angiotensin-converting enzyme 2 in experimental myocardial infarction: implications for future therapeutic directions

2012 ◽  
Vol 123 (11) ◽  
pp. 649-658 ◽  
Author(s):  
Luke J. Burchill ◽  
Elena Velkoska ◽  
Rachael G. Dean ◽  
Karen Griggs ◽  
Sheila K. Patel ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Body Weight ◽  
Angiotensin Converting Enzyme ◽  
Renin Angiotensin System ◽  
Border Zone ◽  
Converting Enzyme ◽  
Angiotensin Receptor ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Cardioprotective Effects

The RAS (renin–angiotensin system) is activated after MI (myocardial infarction), and RAS blockade with ACEis [ACE (angiotensin-converting enzyme) inhibitors] or ARBs (angiotensin receptor blockers) slows but does not completely prevent progression to heart failure. Cardiac ACE is increased after MI and leads to the formation of the vasoconstrictor AngII (angiotensin II). The enzyme ACE2 is also activated after MI and degrades AngII to generate the vasodilator Ang-(1–7) [angiotensin-(1–7)]. Overexpression of ACE2 offers cardioprotective effects in experimental MI, but there is conflicting evidence as to whether the benefits of ACEis and ARBs are mediated through increasing ACE2 after MI. In the present study, we assessed the effect of an ACEi and ARB, alone and in combination, on cardiac ACE2 in a rat MI model. MI rats received vehicle, ACEi (ramipril; 1 mg/kg of body weight), ARB (valsartan; 10 mg/kg of body weight) or combination (ramipril at 1 mg/kg of body weight and valsartan at 10 mg/kg of body weight) orally for 28 days. Sham-operated rats were also studied and received vehicle alone. MI increased LV (left ventricular) mass (P<0.0001), impaired cardiac contractility (P<0.05) and activated cardiac ACE2 with increased gene (P<0.05) and protein expression (viable myocardium, P<0.05; border zone, P<0.001; infarct, P<0.05). Ramipril and valsartan improved remodelling (P<0.05), with no additional effect of dual therapy. Although ramipril inhibited ACE, and valsartan blocked the angiotensin receptor, neither treatment alone nor in combination augmented cardiac ACE2 expression. These results suggest that the cardioprotective effects of ramipril and valsartan are not mediated through up-regulation of cardiac ACE2. Strategies that do augment ACE2 after MI may be a useful addition to standard RAS blockade after MI.

scholarly journals Effect of Dual Blockade of Renin-Angiotensin System on Proteinuria

2013 ◽  
Vol 1 (1) ◽  
pp. 18-20
Author(s):  
Eqerem Hasani ◽  
Alma Idrizi ◽  
Myftar Barbullushi
Keyword(s):  
Angiotensin Converting Enzyme ◽  
Angiotensin Receptor Blocker ◽  
Enzyme Inhibitor ◽  
Combined Therapy ◽  
Renin Angiotensin System ◽  
Converting Enzyme ◽  
Angiotensin Receptor ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Dual Blockade

Aim: Aim of the study was the evaluation of the effect of dual blockade of the renin-angiotensin system (RAS) on proteinuria. Material and Methods: Sixty patients, included in the study, were treated with angiotensin-converting enzyme inhibitor and angiotensin receptor blocker for a period of 3 months. Results: The dual blockade of RAS resulted with decrease of proteinuria, a slight increase of serum creatinine and was not associated with a lowering of blood pressure.Conclusion: Combined therapy with ACE-I and ARB results in a more complete blockade of the RAS than monotherapy. In proteinuric nephropathies it reduces significantly baseline proteinuria.

scholarly journals Differences in the expression of the renin angiotensin system and the kallikrein-kinin system during the course of myocardial infarction in male and female Wistar rats

2020 ◽  
Vol 21 (2) ◽  
pp. 147032031990003
Author(s):  
Jazmín Flores-Monroy ◽  
Diego Lezama-Martínez ◽  
Salvador Fonseca-Coronado ◽  
Luisa Martínez-Aguilar
Keyword(s):  
Myocardial Infarction ◽  
Angiotensin Converting Enzyme ◽  
Wistar Rats ◽  
Renin Angiotensin System ◽  
Converting Enzyme ◽  
Kinin System ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Female Wistar Rats ◽  
Kallikrein Kinin System

Background: There is some evidence that components of the renin-angiotensin system and kallikrein-kinin system are not similarly regulated in both sexes. The aim of this work was to analyze the expression of angiotensin-converting enzyme, angiotensin-converting enzyme 2, angiotensin 1 receptor, angiotensin 2 receptor, beta-1 receptor, and beta-2 receptor during the evolution of myocardial infarction. Methods: Thirty-six male and 36 female Wistar rats were used. Myocardial infarction was induced. Six groups of both sexes were formed, ( n=6): (a) sham; (b) 48 h myocardial infarction; (c) one week myocardial infarction; (d) two weeks myocardial infarction; (e) three weeks myocardial infarction and (f) four weeks myocardial infarction. The expression was evaluated by real-time polymerase chain reaction on the penumbra of left ventricle. Results: The mRNA expression of most biomarkers was lower in females than in males. During acute infarction, an increase of all protein expression was found in female and at two weeks while in the male only biomarker changes occurred at three weeks. In addition, in male biomarkers mRNA expression decreased during chronic infarction while in females it did not. Conclusions: The renin-angiotensin system and kallikrein-kinin system biomarkers expression occurs at earlier times in the female than in the male rat. In addition, during chronic myocardial infarction these biomarkers remained unchanged in females while in males they decreased.

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