scholarly journals Renal Angiotensinogen in Nonhuman Primates is Predominantly Liver-Derived

2021 ◽  
Author(s):  
Masayoshi Kukida ◽  
Lei Cai ◽  
Dien Ye ◽  
Hisashi Sawada ◽  
Yuriko Katsumata ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Antisense Oligonucleotides ◽  
Nonhuman Primates ◽  
Primary Source ◽  
Renin Angiotensin System ◽  
Proximal Tubules ◽  
Specific Inhibition ◽  
Angiotensin System ◽  
Renal Proximal Tubules ◽  
Cynomolgus Monkeys

AGT (Angiotensinogen) is the unique substrate of the renin-angiotensin system. Liver is the primary source of circulating AGT. The present study determined whether hepatocyte-derived AGT regulates renal AGT accumulation by injecting ASO (antisense oligonucleotides) targeting hepatocyte-derived AGT (GalNAc AGT ASO) into female cynomolgus monkeys. Hepatocyte-specific inhibition of AGT led to profound reductions of plasma AGT concentrations. AGT protein in S1 and S2 of renal proximal tubules was greatly diminished by GalNAc AGT ASO. Given the similarity between nonhuman primates and human, our findings support the notion that renal AGT is predominantly derived from liver, and liver regulates renal angiotensin II production in humans.

scholarly journals Angiotensin metabolism in renal proximal tubules, urine, and serum of sheep: evidence for ACE2-dependent processing of angiotensin II

2007 ◽  
Vol 292 (1) ◽  
pp. F82-F91 ◽  
Author(s):  
Hossam A. Shaltout ◽  
Brian M. Westwood ◽  
David B. Averill ◽  
Carlos M. Ferrario ◽  
Jorge P. Figueroa ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Renin Angiotensin System ◽  
Experimental Models ◽  
Proximal Tubules ◽  
Ang Ii ◽  
Converting Enzyme ◽  
Angiotensin System ◽  
Stable Product ◽  
Neprilysin Inhibition ◽  
Urine And Serum

Despite the evidence that angiotensin-converting enzyme (ACE)2 is a component of the renin-angiotensin system (RAS), the influence of ACE2 on angiotensin metabolism within the kidney is not well known, particularly in experimental models other than rats or mice. Therefore, we investigated the metabolism of the angiotensins in isolated proximal tubules, urine, and serum from sheep. Radiolabeled [125I]ANG I was hydrolyzed primarily to ANG II and ANG-(1–7) by ACE and neprilysin, respectively, in sheep proximal tubules. The ACE2 product ANG-(1–9) from ANG I was not detected in the absence or presence of ACE and neprilysin inhibition. In contrast, the proximal tubules contained robust ACE2 activity that converted ANG II to ANG-(1–7). Immunoblots utilizing an NH2 terminal-directed ACE2 antibody revealed a single 120-kDa band in proximal tubule membranes. ANG-(1–7) was not a stable product in the tubule preparation and was rapidly hydrolyzed to ANG-(1–5) and ANG-(1–4) by ACE and neprilysin, respectively. Comparison of activities in the proximal tubules with nonsaturating concentrations of substrate revealed equivalent activities for ACE (ANG I to ANG II: 248 ± 17 fmol·mg−1·min−1) and ACE2 [ANG II to ANG-(1–7): 253 ± 11 fmol·mg−1·min−1], but lower neprilysin activity [ANG II to ANG-(1–4): 119 ± 24 fmol·mg−1·min−1; P < 0.05 vs. ACE or ACE2]. Urinary metabolism of ANG I and ANG II was similar to the proximal tubules; soluble ACE2 activity was also detectable in sheep serum. In conclusion, sheep tissues contain abundant ACE2 activity that converts ANG II to ANG-(1–7) but does not participate in the processing of ANG I into ANG-(1–9).

scholarly journals Expression of Components of the Renin-angiotensin System in Autosomal Recessive Polycystic Kidney Disease

2005 ◽  
Vol 53 (8) ◽  
pp. 979-988 ◽  
Author(s):  
Mahmoud Loghman-Adham ◽  
Carlos E. Soto ◽  
Tadashi Inagami ◽  
Cirilo Sotelo-Avila
Keyword(s):  
Angiotensin Ii ◽  
Kidney Disease ◽  
Polycystic Kidney Disease ◽  
Autosomal Recessive ◽  
Renin Angiotensin System ◽  
Proximal Tubules ◽  
Polycystic Kidney ◽  
Angiotensin System ◽  
Intrarenal Ras ◽  
Immunohistochemical Studies

Hypertension is a common complication in children with autosomal recessive polycystic kidney disease (ARPKD) who have survived the neonatal period. No information is available regarding the mechanism of hypertension in this condition. The renin-angiotensin system (RAS) is thought to play a role in hypertension associated with the more common autosomal dominant polycystic kidney disease (ADPKD). Occasional reports have documented increased activity of the intrarenal RAS in ADPKD, with ectopic renin expression within cysts and dilated tubules. Because of similarities between ARPKD and ADPKD, we hypothesized that increased intrarenal RAS activity might also be found in ARPKD. We performed immunohistochemical studies on kidney tissues from two infants with ARPKD and two control kidneys. The cystic dilated tubules showed staining with the peanut lectin arachis hypogaea, a marker of distal tubules and collecting ducts, but not with lotus tetragonolobus, a marker of proximal tubules. Strong renin staining was seen in many cysts and tubules of ARPKD kidneys, but only in the afferent arterioles of the normal control kidneys. Angiotensinogen staining was also observed in some cysts and in proximal tubules. Staining for angiotensin-converting enzyme, angiotensin II type 1 receptor, and angiotensin II peptide was present in many cystic dilated tubules. These immunohistochemical studies document for the first time ectopic expression of components of the RAS in cystic-dilated tubules of ARPKD and suggest that overactivity of RAS could result in increased intrarenal angiotensin II production, which may contribute to the development of hypertension in ARPKD.

A Review of Angiotensin Receptor Blocker-based Therapies at all Levels of Cardiovascular Risk

2011 ◽  
Vol 7 (4) ◽  
pp. 254 ◽  
Author(s):  
Giuliano Tocci ◽  
Lorenzo Castello ◽  
Massimo Volpe ◽  
◽  
◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Ventricular Hypertrophy ◽  
Renin Angiotensin System ◽  
Left Ventricular ◽  
Clinical Settings ◽  
Angiotensin Ii Receptor ◽  
Angiotensin System ◽  
Receptor Blockers ◽  
Artery Disease

The renin–angiotensin system (RAS) has a key role in the maintenance of cardiovascular homeostasis, and water and electrolyte metabolism in healthy subjects, as well as in several diseases including hypertension, left ventricular hypertrophy and dysfunction, coronary artery disease, renal disease and congestive heart failure. These conditions are all characterised by abnormal production and activity of angiotensin II, which represents the final effector of the RAS. Over the last few decades, accumulating evidence has demonstrated that antihypertensive therapy based on angiotensin II receptor blockers (ARBs) has a major role in the selective antagonism of the main pathological activities of angiotensin II. Significant efforts have been made to demonstrate that blocking the angiotensin II receptor type 1 (AT1) subtype receptors through ARB-based therapy results in proven benefits in different clinical settings. In this review, we discuss the main benefits of antihypertensive strategies based on ARBs in terms of their efficacy, safety and tolerability.

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.

Renin-angiotensin system and aldosterone secretion during aortic constriction in the rat

1977 ◽  
Vol 232 (5) ◽  
pp. F434-F437 ◽  
Author(s):  
R. H. Freeman ◽  
J. O. Davis ◽  
W. S. Spielman
Keyword(s):  
Angiotensin Ii ◽  
Perfusion Pressure ◽  
Renin Angiotensin System ◽  
Renal Perfusion ◽  
Bilateral Nephrectomy ◽  
Aortic Constriction ◽  
Aldosterone Secretion ◽  
Experimental Conditions ◽  
Angiotensin System ◽  
Renin Angiotensin

Suprarenal aortic constriction sufficient to reduce renal perfusion pressure by approximately 50% increased aldosterone secretion in anesthetized rats pretreated with dexamethasone. Bilateral nephrectomy under the same experimental conditions blocked the aldosterone response. Additionally, [1-sarcosine, 8-alanine]angiotensin II blocked the response in aldosterone secretion to aortic constriction in dexamethasone-treated rats. Finally, in rats hypophysectomized to exclude the influence of ACTH, the aldosterone response to aortic constriction was blocked by [1-sarcosine, 8-alanine]angiotensin II. The results indicate that angiotensin II increased aldosterone secretion during aortic constriction in the rat. These observations, along with those reported previously in sodium-depleted rats, point to an important overall role for the renin-angiotensin system in the control of aldosterone secretion in the rat.

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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