scholarly journals The cortical collecting duct plays a pivotal role in kidney local renin-angiotensin system

2013 ◽  
Vol 154 (17) ◽  
pp. 643-649 ◽  
Author(s):  
Rózsa Csohány ◽  
Ágnes Prókai ◽  
Anna Kosik ◽  
J. Attila Szabó
Keyword(s):  
Animal Studies ◽  
Collecting Duct ◽  
Renin Angiotensin System ◽  
Juxtaglomerular Apparatus ◽  
Systemic Circulation ◽  
The Body ◽  
Signal Pathways ◽  
Cortical Collecting Duct ◽  
Angiotensin System ◽  
Renin Angiotensin

The renin-angiotensin system is one of the most important hormone systems in the body, and the regulations as well as the role in the juxtaglomerular apparatus are well known. The present review focuses on renin secretion in a recently described localization, the cortical collecting duct. The authors display it in parallel of the copying strategy of an adult and a developing kidney. Furthermore, based on different animal studies it highlights the local role of renin released from the collecting duct. In chronic angiotensin II-infused, 2-kidney, 1-clip hypertensive model as well as in diabetic rats the major source of (pro)renin is indeed the collecting duct. In this localization this hormone can reach both the systemic circulation and the interstitial renin-angiotensin system components including the newly described (pro)renin receptor, by which (pro)renin is able to locally activate pro-fibrotic intracellular signal pathways. Consequently, one can postulate that in the future renin may serve either as a new therapeutic target in nephropathy associated with both hypertension and diabetes or as an early diagnostic marker in chronic diseases leading to nephropathy. Orv. Hetil., 2013, 154, 643–649.

scholarly journals Activation of the Alternate Renin-Angiotensin System Correlates with the Clinical Status in Human Cirrhosis and Corrects Post Liver Transplantation

2019 ◽  
Vol 8 (4) ◽  
pp. 419 ◽  
Author(s):  
Stephen Casey ◽  
Robert Schierwagen ◽  
Kai Mak ◽  
Sabine Klein ◽  
Frank Uschner ◽  
...  
Keyword(s):  
Liver Transplantation ◽  
Liver Disease ◽  
Animal Studies ◽  
Clinical Status ◽  
Renin Angiotensin System ◽  
Blood Sampling ◽  
Ang Ii ◽  
Post Transplantation ◽  
Angiotensin System ◽  
Renin Angiotensin

Introduction: Recent animal studies have shown that the alternate renin-angiotensin system (RAS) consisting of angiotensin-converting enzyme 2 (ACE2), angiotensin-(1–7) (Ang-(1–7)) and the Mas receptor is upregulated in cirrhosis and contributes to splanchnic vasodilatation and portal hypertension. To determine the potential relevance of these findings to human liver disease, we evaluated its expression and relationship to the patients’ clinical status in subjects with cirrhosis. Methods: Blood sampling from peripheral and central vascular beds was performed intra-operatively for cirrhotic patients at the time of liver transplantation (LT) or trans-jugular intra-hepatic portosystemic shunt (TIPS) procedures to measure angiotensin II (Ang II) and Ang-(1–7) peptide levels and ACE and ACE2 enzyme activity. Relevant clinical and hemodynamic data were recorded pre-operatively for all subjects and peripheral blood sampling was repeated 3 months or later post-operatively. Results: Ang-(1–-7) and ACE2 activity were up-regulated more than twofold in cirrhotic subjects both at the time of LT and TIPS and levels returned to comparable levels as control subjects post-transplantation. Ang-(1–7) levels correlated positively with the degree of liver disease severity, as measured by the model for an end-stage liver disease (MELD) and also with clinical parameters of pathological vasodilatation including cardiac output (CO). There were strong correlations found between the ACE2:ACE and the Ang-(1–7):Ang II ratio highlighting the inter-dependence of the alternate and classical arms of the RAS and thus their potential impact on vascular tone. Conclusions: In human cirrhosis, the alternate RAS is markedly upregulated and the activation of this system is associated strongly with features of the hyperdynamic circulation in advanced human cirrhosis.

Plasma renin activity and forearm blood flow in paraplegic humans

1985 ◽  
Vol 59 (3) ◽  
pp. 924-927 ◽  
Author(s):  
P. R. Freund ◽  
G. L. Brengelmann
Keyword(s):  
Blood Flow ◽  
Plasma Renin Activity ◽  
Forearm Blood Flow ◽  
Control Period ◽  
Renin Angiotensin System ◽  
Plasma Renin ◽  
The Body ◽  
Renin Activity ◽  
Angiotensin System ◽  
Renin Angiotensin

We recently found that paraplegic humans respond to hyperthermia with subnormal increase in skin blood flow (SkBF), based on measurements of forearm blood flow (FBF). Is this inhibition of SkBF a defect in thermoregulation or a cardiovascular adjustment necessary for blood pressure control? Since high resting plasma renin activity (PRA) is found in unstressed individuals with spinal cord lesions and since PRA increases during hyperthermia in normal humans, we inquired whether the renin-angiotensin system is responsible for the attenuated FBF in hyperthermic resting paraplegics. Five subjects, 28–47 yr, with spinal transections (T1-T10), were heated in water-perfused suits. Blood samples for PRA determinations were collected during a control period and after internal temperature reached approximately 38 degrees C. Some subjects with markedly attenuated FBF had little or no elevation of PRA; those with the best-developed FBF response exhibited the highest PRA. Clearly, circulating angiotensin is not the agent that attenuates SkBF. Rather, increased activity of the renin-angiotensin system may be a favorable adaptation that counters the locally mediated SkBF increase in the lower body and thus allows controlled active vasodilation in the part of the body subject to centrally integrated sympathetic effector outflow.

Exploring the Evidence Implicating the Renin-Angiotensin System (RAS) in the Physiopathology of Mood Disorders

2020 ◽  
Vol 27 (6) ◽  
pp. 449-455 ◽  
Author(s):  
Satyajit Mohite ◽  
Marsal Sanches ◽  
Antonio L. Teixeira
Keyword(s):  
Mood Disorders ◽  
Animal Studies ◽  
Renin Angiotensin System ◽  
Neurocognitive Deficits ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Ras Inhibition ◽  
Health Significance ◽  
At1 Blockers

Mood disorders include Major Depressive Disorder (MDD), Bipolar Disorder (BD) and variations of both. Mood disorders has a public health significance with high comorbidity, suicidal mortality and economic burden on the health system. Research related to mood disorders has evolved over the years to relate it with systemic conditions. The Renin Angiotensin System (RAS) has been noticed to play major physiological roles beyond renal and cardiovascular systems. Recent studies have linked RAS not only with neuro-immunological processes, but also with psychiatric conditions like mood and anxiety disorders. In this comprehensive review, we integrated basic and clinical studies showing the associations between RAS and mood disorders. Animal studies on mood disorders models - either depression or mania - were focused on the reversal of behavioral and/or cognitive symptoms through the inhibition of RAS components like the Angiotensin- Converting Enzyme (ACE), Angiotensin II Type 1 receptor (AT1) or Mas receptors. ACE polymorphisms, namely insertion-deletion (I/D), were linked to mood disorders and suicidal behavior. Hypertension was associated with neurocognitive deficits in mood disorders, which reversed with RAS inhibition. Low levels of RAS components (renin activity or aldosterone) and mood symptoms improvement with ACE inhibitors or AT1 blockers were also observed in mood disorders. Overall, this review reiterates the strong and under-researched connection between RAS and mood disorders.

The Human-Covid Tango: Connecting the Dots

2020 ◽  
Author(s):  
Hamdi Hamdi ◽  
Ensaf Abdaldayem
Keyword(s):  
Coming Out ◽  
Renin Angiotensin System ◽  
The Elderly ◽  
Cardiovascular Complications ◽  
Scientific Activity ◽  
The Body ◽  
Angiotensin System ◽  
Angiotensin Converting Enzyme 2 ◽  
Renin Angiotensin ◽  
Connecting The Dots

As the world grapples with a hot pandemic with various and expanding epicenters, a flurry of medical and scientific activity has gained speed and momentum in a race to halt Covid-19. Due to the urgency of the situation, publication peer review has been speeded up to get information published and turn the gears of research in search for a cure. A hot and controversial topic has been the connection between Covid-19 and the Renin-angiotensin system (RAS). Covid-19, like Sars before it, enters by way of the Angiotensin Converting Enzyme 2 (ACE2). ACE2 is ubiquitously expressed in many tissues in the body serving as the doorway by which the virus can enter and spread causing inflammatory havoc. Demographic evidence coming out of china and other locations make it clear that the elderly and those suffering cardiovascular complications such as hypertension etc are most at risk. The connection to RAS and the demographic nature of the data coming out has led many to advance hypothesis, recommendations and even therapies based on existing RAS inhibitors and other components of the renin-angiotensin system. It is pertinent to review the literature in the context of our understanding of the renin-angiotesnin system to allow better judgements to be made as well as lines of research initiated advancing a quick resolution to Covid-19.

Angiotensin-dependent renal mechanisms in two-kidney, one-clip renal vascular hypertension

1983 ◽  
Vol 245 (2) ◽  
pp. F131-F141 ◽  
Author(s):  
D. W. Ploth
Keyword(s):  
Blood Pressure ◽  
Renin Angiotensin System ◽  
Systemic Blood Pressure ◽  
Systemic Circulation ◽  
Systemic Hemodynamic ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Renal Vascular ◽  
Pharmacologic Agents

Our understanding of the physiology of the renin-angiotensin system has advanced remarkably in the last decade as a result of the development of several pharmacologic agents that effectively block components of this humoral cascade. The use of these antagonists has also advanced our understanding of the contribution of the renin-angiotensin system to the development and maintenance of two-kidney, one-clip renal vascular hypertension. These antagonists have contributed greatly to the characterization of the systemic hemodynamic changes that occur in this model and, particularly, to the delineation of the behavior of the nonclipped kidney, a previously normal kidney that is subjected acutely to an environment of elevated systemic blood pressure and the input of a variety of other extrinsic influences. This kidney not only allows the blood pressure to increase and persist at elevated levels but appears to actively participate in the development and propagation of the hypertension. Although a variety of mechanisms impinge on the function of the nonclipped kidney in this model, the goal of this review is to analyze the behavior of this kidney and how its functional state is perturbed, primarily by the influence of angiotensin, which is believed to be delivered to it by the systemic circulation.

scholarly journals ELABELA antagonizes intrarenal renin-angiotensin system to lower blood pressure and protects against renal injury

2020 ◽  
Vol 318 (5) ◽  
pp. F1122-F1135 ◽  
Author(s):  
Chuanming Xu ◽  
Fei Wang ◽  
Yanting Chen ◽  
Shiying Xie ◽  
Danielle Sng ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Protein Expression ◽  
Collecting Duct ◽  
Protective Action ◽  
Renin Angiotensin System ◽  
Mrna Levels ◽  
Distal Nephron ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Intrarenal Ras

Emerging evidence has demonstrated that (pro)renin receptor (PRR)-mediated activation of intrarenal renin-angiotensin system (RAS) plays an essential role in renal handling of Na+ and water balance and blood pressure. The present study tested the possibility that the intrarenal RAS served as a molecular target for the protective action of ELABELA (ELA), a novel endogenous ligand of apelin receptor, in the distal nephron. By RNAscope and immunofluorescence, mRNA and protein expression of endogenous ELA was consistently localized to the collecting duct (CD). Apelin was also found in the medullary CDs as assessed by immunofluorescence. In cultured CD-derived M1 cells, exogenous ELA induced parallel decreases of full-length PRR (fPRR), soluble PRR (sPRR), and prorenin/renin protein expression as assessed by immunoblotting and medium sPRR and prorenin/renin levels by ELISA, all of which were reversed by 8-bromoadenosine 3′,5′-cyclic monophosphate. Conversely, deletion of PRR in the CD or nephron in mice elevated Apela and Apln mRNA levels as well as urinary ELA and apelin excretion, supporting the antagonistic relationship between the two systems. Administration of exogenous ELA-32 infusion (1.5 mg·kg−1·day−1, minipump) to high salt (HS)-loaded Dahl salt-sensitive (SS) rats significantly lowered mean arterial pressure, systolic blood pressure, diastolic blood pressure, and albuminuria, accompanied with a reduction of urinary sPRR, angiotensin II, and prorenin/renin excretion. HS upregulated renal medullary protein expression of fPRR, sPRR, prorenin, and renin in Dahl SS rats, all of which were significantly blunted by exogenous ELA-32 infusion. Additionally, HS-induced upregulation of inflammatory cytokines ( IL-1β, IL-2, IL-6, IL-17A, IFN-γ, VCAM-1, ICAM-1, and MCP-1), fibrosis markers ( TGF-β1, FN, Col1A1, PAI-1, and TIMP-1), and kidney injury markers ( NGAL, Kim-1, albuminuria, and urinary NGAL excretion) were markedly blocked by exogenous ELA infusion. Together, these results support the antagonistic interaction between ELA and intrarenal RAS in the distal nephron that appears to exert a major impact on blood pressure regulation.

scholarly journals Effect of Estrogen upon the Juxtaglomerular Apparatus and the Renin-Angiotensin System in Rats

1978 ◽  
Vol 126 (3) ◽  
pp. 267-272
Author(s):  
KAZUOKI KONDO ◽  
JIRO MISUMI ◽  
RYUICHI NAKAMURA ◽  
IKUO SAITO ◽  
TAKAO SARUTA
Keyword(s):  
Renin Angiotensin System ◽  
Juxtaglomerular Apparatus ◽  
Angiotensin System ◽  
Renin Angiotensin

scholarly journals The ACE2/Angiotensin-(1–7)/MAS Axis of the Renin-Angiotensin System: Focus on Angiotensin-(1–7)

2018 ◽  
Vol 98 (1) ◽  
pp. 505-553 ◽  
Author(s):  
Robson Augusto Souza Santos ◽  
Walkyria Oliveira Sampaio ◽  
Andreia C. Alzamora ◽  
Daisy Motta-Santos ◽  
Natalia Alenina ◽  
...  
Keyword(s):  
Current Knowledge ◽  
Renin Angiotensin System ◽  
The Body ◽  
Biologically Active ◽  
Ang Ii ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
The Past ◽  
The Brain ◽  
System Focus

The renin-angiotensin system (RAS) is a key player in the control of the cardiovascular system and hydroelectrolyte balance, with an influence on organs and functions throughout the body. The classical view of this system saw it as a sequence of many enzymatic steps that culminate in the production of a single biologically active metabolite, the octapeptide angiotensin (ANG) II, by the angiotensin converting enzyme (ACE). The past two decades have revealed new functions for some of the intermediate products, beyond their roles as substrates along the classical route. They may be processed in alternative ways by enzymes such as the ACE homolog ACE2. One effect is to establish a second axis through ACE2/ANG-(1–7)/MAS, whose end point is the metabolite ANG-(1–7). ACE2 and other enzymes can form ANG-(1–7) directly or indirectly from either the decapeptide ANG I or from ANG II. In many cases, this second axis appears to counteract or modulate the effects of the classical axis. ANG-(1–7) itself acts on the receptor MAS to influence a range of mechanisms in the heart, kidney, brain, and other tissues. This review highlights the current knowledge about the roles of ANG-(1–7) in physiology and disease, with particular emphasis on the brain.

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