Activity and responsiveness of the renin-angiotensin system in the aging rat

2000 ◽  
Vol 279 (5) ◽  
pp. R1787-R1794 ◽  
Author(s):  
Michele M. Thompson ◽  
Terry T. Oyama ◽  
Francis J. Kelly ◽  
Thomas M. Kennefick ◽  
Sharon Anderson

The systemic renin-angiotensin system (RAS) is suppressed in normal aging, but the activity of the tissue RAS is not well defined. We examined the systemic and intrarenal RAS status of aging normal rats and responses to suppression and stimulation of the production of endogenous ANG II. Studies were performed in young (3 mo) and early aging (15 mo) male Sprague-Dawley rats. Angiotensin-converting enzyme inhibitors modestly decreased mean arterial pressure (MAP) in young (3 mo) and early aging (15 mo) rats and limited proteinuria in the older rats. There were no significant age-related effects on renal function or on endogenous RAS activity. Intravenous infusion of the precursor ANG I led to comparable increases in MAP in younger and older rats. In contrast, the renal effects (reduction in glomerular filtration and plasma flow rates) were exaggerated in the older animals. Intrarenal arterial ANG I did not affect MAP in any group. In young rats, there were no significant hemodynamic effects in either the ipsilateral (infused) or the contralateral (noninfused) kidney. In the older rats, both kidneys had a significant fall in renal renal plasma flow rate (RPF) with left renal arterial infusion of ANG I. Accordingly, these studies early in the course of aging found only subtle changes in the activity, responsiveness, and metabolism of the RAS. Thus early aging is associated with a modest but important increase in sensitivity to RAS stimulation.

ESC CardioMed ◽  
2018 ◽  
pp. 1844-1848
Author(s):  
Marc A. Pfeffer

Several classes of inhibitors of the renin–angiotensin system were developed as antihypertensive agents. Following the early observations of favourable haemodynamic effects of angiotensin-converting enzyme inhibitors (ACEIs) in patients with congestive heart failure, a series of major randomized outcome trials demonstrated morbidity and mortality benefits of these agents across the spectrum of patients with heart failure with reduced ejection fraction (HFrEF). Angiotensin receptor blockers (ARBs) were then also shown to have similar benefits with a suggestion of some incremental improvements when used together. However, in the trials that randomized patients to a proven dose of an ACEI plus either placebo or an ARB, the combination of the two inhibitors of the renin–angiotensin system resulted in more adverse drug effects without a meaningful improvement in clinical outcomes. This chapter reviews the fundamental underpinnings for use of either an ACEI or ARB to improve prognosis of patients with HFrEF.


2020 ◽  
Vol 27 (6) ◽  
pp. 512-519 ◽  
Author(s):  
Karina Lúcia Moreira Sassi ◽  
Laís Bhering Martins ◽  
Aline Silva de Miranda ◽  
Antonio Lucio Teixeira

Migraine is a common neurologic condition marked by recurrent episodes of headache. Its pathophysiology is highly complex involving neuronal, inflammatory and vascular mechanisms. The Renin-Angiotensin System (RAS) can modulate all these mechanism, being a potential pharmacological target for migraine treatment. We carried out a systematic review of the studies evaluating the involvement of RAS in patients with migraine. There is evidence from genetic studies exploring the relation between migraine and RAS-related genes and from clinical trials evaluating the efficacy of Angiotensin II Type 1 (AT1) receptor antagonists and angiotensin converting enzyme inhibitors in migraine prophylaxis. RAS seems to play a role in the pathophysiology of migraine, but more direct evidence is still missing.


2021 ◽  
Vol 27 ◽  
Author(s):  
Ehsan Tabatabai ◽  
Majid Khazaei ◽  
Mohammad Reza Parizadeh ◽  
Mohammad Nouri ◽  
Seyed Mahdi Hassanian ◽  
...  

: Colorectal cancer is the third most common cancer globally. Despite extensive preclinical and clinical studies, it is still among the leading causes of cancer-related death, and a need for new therapeutic options is required. The renin-angiotensin system plays an important role in regulating blood pressure and cell growth. In addition to their hemodynamic effects, some of the renin-angiotensin system components, such as angiotensin, are also growth factors that promote cell proliferation and angiogenesis, and its dysregulation is reported to be associated with poor prognosis in colorectal cancer. Here we describe the critical role of the renin-angiotensin system pathway in colorectal cancer as well as the preclinical and clinical investigations renin-angiotensin system inhibitors: angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers as a potential therapeutic target in the treatment of colorectal cancer. Several studies have been shown that the inhibition of these pathways can reduce tumor growth and metastasis; however, some of the data remain inconsistent. There is accumulating evidence of the therapeutic potential of some inhibitors, such as Losartan which are now in clinical phases in the treatment of several malignancies using Nivolumab in combination with FOLFIRINOX in pancreatic cancer. Further investigations are warranted to improve the efficacy and selectivity of current and future anticancer strategies targeting renin-angiotensin systems.


2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Borja Quiroga ◽  
David Arroyo ◽  
Gabriel de Arriba

Diabetic kidney disease is the leading cause of end-stage renal disease. Albuminuria is recognized as the most important prognostic factor for chronic kidney disease progression. For this reason, blockade of renin-angiotensin system remains the main recommended strategy, with either angiotensin converting enzyme inhibitors or angiotensin II receptor blockers. However, other antiproteinuric treatments have begun to be studied, such as direct renin inhibitors or aldosterone blockers. Beyond antiproteinuric treatments, other drugs such as pentoxifylline or bardoxolone have yielded conflicting results. Finally, alternative pathogenic pathways are being explored, and emerging therapies including antifibrotic agents, endothelin receptor antagonists, or transcription factors show promising results. The aim of this review is to explain the advances in newer agents to treat diabetic kidney disease, along with the background of the renin-angiotensin system blockade.


Nephron ◽  
2021 ◽  
pp. 1-8
Author(s):  
Mei Mei ◽  
Zulian Zhou ◽  
Qian Zhang ◽  
Yi Chen ◽  
Hongwen Zhao ◽  
...  

Studies on pharmacological mechanisms demonstrated that a strategy of dual renin-angiotensin system (RAS) blockade may have a synergistic effect in the treatment of cardiorenal diseases and may reduce adverse reactions. However, some previous clinical studies reported that dual RAS blockade did not significantly benefit many patients with cardiorenal diseases and increased the risk of hyperkalemia, hypotension and renal function damage. Therefore, the current clinical guidelines suggest that the combined use of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) should be used with caution in the clinic. However, these studies enrolled older patients with cardiovascular risk factors, and the results of these trials may not be generalized to the overall population. Some clinical evidence suggests that the combination of low-dose ACEIs and ARBs leads to more effective RAS blockade with few adverse effects. The advent of new RAS inhibitors with superior pharmacological effects provides a more suitable drug choice for individualized therapy for dual RAS blockade. Therefore, the choice of appropriate ARBs/ACEIs for individualized therapy based on patient condition may be a better way to improve the efficiency and safety of the dual RAS blockade strategy.


2001 ◽  
Vol 26 (3) ◽  
pp. 155-164 ◽  
Author(s):  
PS Leung ◽  
PO Carlsson

The classical concept of the renin-angiotensin system (RAS) is that of a blood-borne cascade, whose final and bioactive product, angiotensin II, plays an important endocrine role in the maintenance of blood pressure and electrolyte as well as fluid balance. In addition to this circulating RAS, there are an increasing number of studies to suggest the existence of a local angiotensin-generating system in several tissues. The so-called tissue RAS can act locally as a paracrine and/or autocrine factor in meeting specific needs for individual tissues and it can operate, in whole or in part, independently of the circulating counterpart. Recent studies on the expression and localization of key RAS components, particularly angiotensinogen and renin, have provided solid evidence for the existence of an intrinsic, angiotensin-generating system in the pancreas. The tissue RAS has a potential role in finely regulating exocrine and endocrine functions of the pancreas such as ductal anion secretion and islet hormonal secretion. Some of these effects may be exerted via the markedly vasoconstrictive effects of RAS. Of particular interest in this context are the recent epidemiological data showing that administration of angiotensin-converting enzyme inhibitors appears to be protective against the development of diabetes in hypertensive patients. Moreover, the upregulation of pancreatic RAS has been shown to occur during chronic hypoxia. The significance of changes in pancreatic RAS could have a potential role in acute pancreatitis, islet transplantation and in different shock states, by causing a further decrease of blood perfusion in the pancreas.


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