Tissue Expression of Components of the Renin—Angiotensin System in Experimental Post-Infarction Heart Failure in Rats: Effects of Heart Failure and Angiotensin-Converting Enzyme Inhibitor Treatment

1997 ◽  
Vol 92 (5) ◽  
pp. 455-465 ◽  
Author(s):  
Martin P. Kelly ◽  
OLE Kahr ◽  
Christian Aalkjaer ◽  
Frederic Cumin ◽  
Nilesh J Samani

1. It has been suggested that local tissue renin—angiotensin systems may be activated in heart failure and that effects on such systems may, at least partially, explain the beneficial effects of angiotensin-converting enzyme (ACE) inhibitors in this syndrome. To investigate these hypotheses, we examined expression of renin-angiotensin system components in several tissues in a rodent model of post-myocardial infarction (MI) heart failure, and analysed whether such expression is modified by ACE inhibitor treatment. 2. Four groups of rats (n = 8–12 per group) were studied 30 days after surgery: (A) sham-operated rats with no treatment, (B) rats with post-MI heart failure induced by ligation of the left coronary artery, (C) sham-operated rats treated with the ACE inhibitor perindopril (1.5 mg day−1 kg−1), and (D) rats as per B, but treated with perindopril. Expression of renin, angiotensinogen, ACE and angiotensin subtype 1 receptor was assessed by quantification of their respective mRNAs by Northern blotting. 3. Renal renin mRNA increased 2-fold in animals with MI (group B) compared with controls (group A) (P < 0.05) and between 50 and 100-fold after ACE inhibitor treatment (P < 0.001). No change in renin gene expression was found in any extra-renal site either following MI or after ACE inhibitor treatment. Hepatic angiotensinogen mRNA level was similar in all groups, but kidney angiotensinogen mRNA level was increased 1.6-fold (P < 0.01) in the groups receiving perindopril. ACE mRNA level in the lung was not affected by ACE inhibitor treatment but decreased by 50% following MI (groups B and D, P < 0.01). This was associated with a similar (50%, P < 0.01) fall in lung ACE activity and was correlated with the severity of heart failure. Angiotensin subtype 1 receptor mRNA level was not affected in any tissue by either MI or ACE inhibitor treatment. 4. We did not find a systematic activation of tissue renin-angiotensin systems, as assessed by steady-state mRNA levels of key components of the system in experimental post-MI heart failure, or a major effect of ACE inhibitor treatment on expression of these components. However, we observed tissue-specific changes in expression of selected components of the renin-angiotensin system in the kidney and the lung in post-MI heart failure and after ACE inhibitor treatment, which may be of relevance to the pathophysiology of the syndrome and the effects of ACE inhibition.

Endocrinology ◽  
2007 ◽  
Vol 148 (5) ◽  
pp. 2453-2457 ◽  
Author(s):  
Shigeyuki Wakahara ◽  
Tadashi Konoshita ◽  
Shinichi Mizuno ◽  
Makoto Motomura ◽  
Chikako Aoyama ◽  
...  

Angiotensin-converting enzyme (ACE) 2, a newly emerging component of the renin-angiotensin system, is presumed to be a counterregulator against ACE in generating and degrading angiotensin II. It remains to be elucidated how mRNA levels of these two genes are quantitatively regulated in the kidney and also what kind of clinicopathological characteristics could influence the gene expressions in humans. Seventy-eight cases of biopsy-proven renal conditions were examined in detail. Total RNA from a small part of each renal cortical biopsy specimen was reverse transcribed, and the resultant cDNA was amplified for ACE, ACE2, and glyceraldehyde-3-phosphate dehydrogenase with a real-time PCR system. Then we investigated the relationship between clinicopathological variables and mRNA levels adjusted for glyceraldehyde-3-phosphate dehydrogenase. Statistically significant correlation was not observed between any clinicopathological variables and either of the gene expressions by pairwise comparison. However, a strong correlation was observed between the gene expressions of ACE and those of ACE2. Moreover, the ACE to ACE2 ratio was significantly higher in subjects with hypertension (HT) than that in subjects without HT. Whereas parameters of renal function, e.g. urinary protein excretion (UPE) and creatinine clearance (Ccr), are not significantly related to the ACE to ACE2 ratio as a whole, the HT status may reflect disease-induced deterioration of renal function. That is, UPE and Ccr of subjects with HT are significantly different from those without HT, in which a significant correlation is also observed between UPE and Ccr. Finally, stepwise regression analysis further revealed that only the HT status is an independent confounding determinant of the ACE to ACE2 ratio among the variables tested. Our data suggest that ACE2 might play an important role in maintaining a balanced status of local renin-angiotensin system synergistically with ACE by counterregulatory effects confounded by the presence of hypertension. Thus, ACE2 may exert pivotal effects on cardiovascular and renal conditions.


Author(s):  
Matthew M Y Lee ◽  
Kieran F Docherty ◽  
Naveed Sattar ◽  
Neil Mehta ◽  
Ankur Kalra ◽  
...  

Abstract Aims This meta-analysis provides summary odds ratio (OR) estimates for associations between treatment with (vs. without) renin–angiotensin system blockers and risk of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection and coronavirus disease 2019 (CoViD-19) severity (including case-fatality) in patients with hypertension, and in all patients (irrespective of hypertension). Methods and results PubMed, EMBASE, Web of Science, Google Scholar, medRxiv, and SSRN were searched (2 May 2020 to 12 August 2020) for non-randomized observational CoViD-19 studies. Event/patient numbers were extracted, comparing angiotensin-converting enzyme (ACE) inhibitor/angiotensin-receptor blocker (ARB) treatment (and each separately), to treatment with neither drug, for the outcomes: (i) likelihood of SARS-CoV-2 infection; (ii) CoViD-19 severity [including hospitalization, intensive therapy unit (ITU), ventilation]; (iii) case-fatality. The risk of bias was assessed (ROBINS-I). Random-effects meta-analysis estimates were pooled. Eighty-six studies including 459 755 patients (103 317 with hypertension), were analysed. In patients with hypertension, ACE inhibitor or ARB treatment was not associated with a greater likelihood of SARS-CoV-2 infection in 60 141 patients (OR 1.06, 95% CI 0.99–1.14), hospitalization in 5925 patients (OR 0.90, 0.62–1.31), ITU in 7218 patients (OR 1.06, 0.73–1.56), ventilation (or ITU/ventilation/death) in 13 163 patients (OR 0.91, 0.72–1.15) or case-fatality in 18 735 patients with 2893 deaths (OR 0.75, 0.61–0.92). Conclusion Angiotensin-converting enzyme inhibitors and ARBs appear safe in the context of SARS-CoV-2 infection and should not be discontinued. PROSPERO registration number CRD42020186996.


2004 ◽  
Vol 287 (5) ◽  
pp. H2138-H2146 ◽  
Author(s):  
Joseph Francis ◽  
Shun-Guang Wei ◽  
Robert M. Weiss ◽  
Robert B. Felder

Several recent studies suggest an important role for the brain renin-angiotensin system in the pathogenesis of heart failure. Angiotensin-converting enzyme (ACE) activity and binding of angiotensin type 1 (AT1) receptors, which mediate the central effects of ANG II, are increased in heart failure. The present study examined the relationship between brain ACE activity and the autonomic dysregulation characteristic of rats with congestive heart failure. Rats with heart failure (HF) induced by coronary artery ligation and sham-operated control (SHAM) rats were treated with chronic (28 days) third cerebral ventricle [intracerebroventricular (ICV)] or intraperitoneal (IP) infusion of a low dose of the ACE inhibitor enalaprilat (ENL) or vehicle (VEH). VEH-treated HF rats had increased sodium consumption, reduced urine sodium and urine volume, and increased sympathetic nerve activity with impaired baroreflex regulation. These responses were minimized or prevented by ICV ENL started 24 h after coronary ligation. IP ENL at the low dose used in these studies had no beneficial effects on HF rats. Neither IP nor ICV ENL had any substantial effect on the SHAM rats. The findings confirm a critically important contribution of the brain renin-angiotensin system to the pathophysiology of congestive heart failure.


2017 ◽  
Vol 6 (1) ◽  
pp. 9-19 ◽  
Author(s):  
Sarah J Delforce ◽  
Eugenie R Lumbers ◽  
Celine Corbisier de Meaultsart ◽  
Yu Wang ◽  
Anthony Proietto ◽  
...  

A dysfunctional endometrial renin–angiotensin system (RAS) could aid the growth and spread of endometrial cancer. To determine if the RAS is altered in endometrial cancer, we measured RAS gene expression and protein levels in 30 human formalin-fixed, paraffin-embedded (FFPE) endometrioid carcinomas and their adjacent endometrium. All components of the RAS were expressed in most tumours and in adjacent endometrium; mRNA levels of (pro)renin receptor (ATP6AP2), angiotensin II type 1 receptor (AGTR1), angiotensin-converting enzyme (ACE1) and angiotensin-converting enzyme 2 (ACE2) mRNA levels were greater in tumour tissue than adjacent non-cancerous endometrium (P = 0.023, 0.008, 0.004 and 0.046, respectively). Prorenin, ATP6AP2, AGTR1, AGTR2 and ACE2 proteins were abundantly expressed in both cancerous and adjacent non-cancerous endometrium. Staining was most intense in cancerous glandular epithelium. One potential target of the endometrial RAS, transforming growth factor beta-1 (TGFB1), which is essential for epithelial-to-mesenchymal transition, was also upregulated in endometrial cancer tissue (P = 0.001). Interestingly, TGFB1 was strongly correlated with RAS expression and was upregulated in tumour tissue. This study is the first to characterise the mRNA and protein expression of all RAS components in cancerous and adjacent non-cancerous endometrium. The greater expression of ATP6AP2, AGTR1 and ACE1, key elements of the pro-angiogenic/proliferative arm of the RAS, suggests that the RAS plays a role in the growth and spread of endometrial cancer. Therefore, existing drugs that inhibit the RAS and which are used to treat hypertension may have potential as treatments for endometrial cancer.


2005 ◽  
Vol 288 (6) ◽  
pp. H2637-H2646 ◽  
Author(s):  
Qiming Shao ◽  
Bin Ren ◽  
Vijayan Elimban ◽  
Paramjit S. Tappia ◽  
Nobuakira Takeda ◽  
...  

The activities of both sarcolemmal (SL) Na+-K+-ATPase and Na+/Ca2+ exchanger, which maintain the intracellular cation homeostasis, have been shown to be depressed in heart failure due to myocardial infarction (MI). Because the renin-angiotensin system (RAS) is activated in heart failure, this study tested the hypothesis that attenuation of cardiac SL changes in congestive heart failure (CHF) by angiotensin-converting enzyme (ACE) inhibitors is associated with prevention of alterations in gene expression for SL Na+-K+-ATPase and Na+/Ca2+ exchanger. CHF in rats due to MI was induced by occluding the coronary artery, and 3 wk later the animals were treated with an ACE inhibitor, imidapril (1 mg·kg−1·day−1), for 4 wk. Heart dysfunction and cardiac hypertrophy in the infarcted animals were associated with depressed SL Na+-K+-ATPase and Na+/Ca2+ exchange activities. Protein content and mRNA levels for Na+/Ca2+ exchanger as well as Na+-K+-ATPase α1-, α2- and β1-isoforms were depressed, whereas those for α3-isoform were increased in the failing heart. These changes in SL activities, protein content, and gene expression were attenuated by treating the infarcted animals with imidapril. The beneficial effects of imidapril treatment on heart function and cardiac hypertrophy as well as SL Na+-K+-ATPase and Na+/Ca2+ exchange activities in the infarcted animals were simulated by enalapril, an ACE inhibitor, and losartan, an angiotensin receptor antagonist. These results suggest that blockade of RAS in CHF improves SL Na+-K+-ATPase and Na+/Ca2+ exchange activities in the failing heart by preventing changes in gene expression for SL proteins.


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.


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