scholarly journals Down-regulation of the intrarenal renin-angiotensin system in the aging rat.

1995 ◽  
Vol 5 (8) ◽  
pp. 1573-1580
Author(s):  
F F Jung ◽  
T M Kennefick ◽  
J R Ingelfinger ◽  
J P Vora ◽  
S Anderson
Keyword(s):  
Renal Function ◽  
Angiotensin Converting Enzyme ◽  
Aging Process ◽  
Renin Angiotensin System ◽  
Plasma Renin ◽  
Converting Enzyme ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Renin Mrna ◽  
Aging Kidney

Progressive deterioration of renal function occurs during normal aging. Previous studies on the aging kidney have demonstrated glomerular hemodynamic changes, specifically, glomerular capillary hypertension, as maladaptations that lead to proteinuria and glomerular sclerosis over time. Aging rats treated with angiotensin-converting enzyme inhibition have relatively less proteinuria and sclerosis, suggesting that age-related changes in renal function may be associated with alterations in the intrarenal renin-angiotensin system, which thus may play a major role in the pathogenesis of these maladaptations. To investigate this possibility, renal and systemic renin-angiotensin systems were examined at an early phase of the aging process (3 months) and at a later phase (12 months) in male Sprague-Dawley rats. Although plasma renin and serum angiotensin-converting enzyme concentrations did not differ significantly, the intrarenal system showed down-regulation of renin mRNA and angiotensin-converting enzyme levels with aging, whereas angiotensinogen levels remained stable. The decrease in renin mRNA appeared to precede the fall in plasma renin concentration in the aging process. Additional studies in 15-month-old rats confirmed that, by this time, both basal and stimulated renal renin release rates were impaired in older rats. Thus, both decreased renin synthesis and impaired renin release underlie the fall in plasma renin with normal aging. This decrease may act to lower intrarenal baseline levels of angiotensin II, an adaptation of likely importance in the modulation of intrarenal vascular tone and tubular function in the aging kidney.

scholarly journals Synergistic Expression of Angiotensin-Converting Enzyme (ACE) and ACE2 in Human Renal Tissue and Confounding Effects of Hypertension on the ACE to ACE2 Ratio

Endocrinology ◽  
2007 ◽  
Vol 148 (5) ◽  
pp. 2453-2457 ◽  
Author(s):  
Shigeyuki Wakahara ◽  
Tadashi Konoshita ◽  
Shinichi Mizuno ◽  
Makoto Motomura ◽  
Chikako Aoyama ◽  
...  
Keyword(s):  
Renal Function ◽  
Angiotensin Converting Enzyme ◽  
Pairwise Comparison ◽  
Renin Angiotensin System ◽  
Mrna Levels ◽  
Converting Enzyme ◽  
Gene Expressions ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Clinicopathological Variables

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.

scholarly journals Sustained Dysregulation of the Plasma Renin-angiotensin System in Acute COVID-19

2021 ◽  
Author(s):  
Kevin Burns ◽  
Matthew Cheng ◽  
Todd Lee ◽  
Allison McGeer ◽  
David Sweet ◽  
...  
Keyword(s):  
Angiotensin Converting Enzyme ◽  
Renin Angiotensin System ◽  
Plasma Renin ◽  
Converting Enzyme ◽  
Angiotensin I ◽  
Clinical Trial Registration ◽  
Angiotensin System ◽  
Angiotensin Converting Enzyme 2 ◽  
Renin Angiotensin ◽  
Plasma Angiotensin

Abstract SARS-CoV-2 enters cells by binding to angiotensin-converting enzyme 2 (ACE2), and COVID-19 infection may therefore induce changes in the renin-angiotensin system (RAS). To determine the effects of COVID-19 on plasma RAS components, we measured plasma ACE, ACE2, and angiotensins I, (1-7), and II in 46 adults with COVID-19 at hospital admission and on days 2, 4, 7 and 14, compared to 50 blood donors (controls). We compared survivors vs. non-survivors, males vs. females, ventilated vs. not ventilated, and angiotensin receptor blocker (ARB) and angiotensin-converting enzyme (ACE) inhibitor-exposed vs. not exposed. At admission, COVID-19 patients had higher plasma levels of ACE (p=0.012), ACE2 (p=0.001) and angiotensin-(1-7) (p<0.001) than controls. Plasma ACE and ACE2 remained elevated for 14 days in COVID-19 patients, while plasma angiotensin-(1-7) decreased after 7 days. In adjusted analyses, plasma ACE was higher in males vs. females (p=0.042), and plasma angiotensin I was significantly lower in ventilated vs. non-ventilated patients (p=0.001). In summary, plasma ACE and ACE2 are increased for at least 14 days in patients with COVID-19 infection. Angiotensin-(1-7) levels are also elevated, but decline after 7 days. The results indicate dysregulation of the RAS with COVID-19, with increased circulating ACE2 throughout the course of infection.Clinical Trial Registration: https://clinicaltrials.gov/ Unique Identifier: NCT04510623

Investigation of the Mechanism of β2-Agonist-Induced Activation of the Renin—Angiotensin System

1995 ◽  
Vol 88 (4) ◽  
pp. 433-437 ◽  
Author(s):  
Evelyn A. Millar ◽  
Gordon T. McInnes ◽  
Neil C. Thomson
Keyword(s):  
Angiotensin Ii ◽  
Angiotensin Converting Enzyme ◽  
Serum Potassium ◽  
Renin Angiotensin System ◽  
Plasma Renin ◽  
Converting Enzyme ◽  
Angiotensin System ◽  
Serum Angiotensin Converting Enzyme ◽  
Renin Angiotensin ◽  
Plasma Angiotensin

1. We have previously described activation of the renin—angiotensin system in asthma, and also by high-dose nebulized β2-agonists. In this study we sought to determine the mechanism responsible. 2. The influence of the angiotensin-converting enzyme inhibitor, lisinopril, on the response of the renin—angiotensin system and serum potassium to nebulized salbutamol was investigated in a randomized, double-blind, crossover study in eight healthy volunteers using a factorial block design. On study days, subjects received lisinopril 20 mg orally or identical placebo tablets followed 3 h later by nebulized salbutamol or placebo inhalation; plasma renin, angiotensin II, serum angiotensin-converting enzyme and potassium were measured at intervals for 120 min after inhalation. 3. Following salbutamol, plasma renin and angiotensin II concentrations were increased significantly compared with placebo [mean (SEM) plasma renin of 61.7 (15.6) μ-units/ml and angiotensin II of 17.7 (5.4) pg/mol 15 min after salbutamol, P < 0.05 versus placebo]. Baseline plasma renin concentrations were increased [160.1 (20.6) μ-units/ml] and baseline plasma angiotensin II concentrations were reduced [1.4 (0.1) pg/ml] by lisinopril, P < 0.05 versus placebo in each case. Inhibition of angiotensin-converting enzyme completely inhibited this salbutamol-induced rise in plasma angiotensin II [mean (SEM) plasma angiotensin II of 1.5 (0.4) pg/ml 15 min after salbutamol, P < 0.05 versus placebo] but had no effect on the changes in plasma renin concentrations after the β2-agonist [mean (SEM) plasma renin of 198.4 (18.9) μ-units/ml 15 min after salbutamol]. 4. Serum angiotensin-converting enzyme concentrations tended to increase throughout the study period following salbutamol compared with placebo, although this difference was not statistically significant. Lisinopril caused complete suppression of serum angiotensin-converting enzyme. 5. Salbutamol significantly reduced serum potassium concentrations [mean (SEM) baseline serum potassium of 4.26 (0.16) mmol/l decreasing to 3.08 (0.2) mmol/l at 45 min, P < 0.05 versus placebo]. Although lisinopril had no significant effect on serum potassium, the hypokalaemic response to salbutamol was significantly reduced in the presence of the angiotensin-convering enzyme inhibitor [mean (SEM) decrease in serum potassium of −1.2 (0.2) mmol/l compared with −0.8 (0.2) mmol/l, P < 0.05 versus placebo]. 6. Mean blood pressure was unaffected by active therapy. One subject experienced dizziness and headache after lisinopril. 7. The results of this study confirm that nebulized salbutamol causes activation of plasma renin and angiotensin II. Pretreatment with an angiotensin-converting enzyme inhibitor prevented the salbutamol-induced increase in plasma angiotensin II but not renin concentration. 8. We conclude that elevation of plasma angiotensin II induced by high-dose nebulized β2-agonists involves the classical components of the renin—angiotensin system including angiotensin-converting enzyme.

Effect of Hypoxia and β2-Agonists on the Activity of the Renin-Angiotensin System in Normal Subjects

1995 ◽  
Vol 89 (3) ◽  
pp. 273-276 ◽  
Author(s):  
Evelyn A. Millar ◽  
Robert M. Angus ◽  
Jane E. Nally ◽  
Robin Clayton ◽  
Neil C. Thomson
Keyword(s):  
Angiotensin Ii ◽  
Angiotensin Converting Enzyme ◽  
Healthy Subjects ◽  
Renin Angiotensin System ◽  
Plasma Renin ◽  
Converting Enzyme ◽  
Angiotensin System ◽  
Serum Angiotensin Converting Enzyme ◽  
Renin Angiotensin ◽  
Β2 Agonists

1. We have reported that the renin-angiotensin system is activated in acute asthma, and also by high-dose nebulized β2-agonists. The contribution of other possible stimuli such as hypoxia is unknown. The present study examined the effect of hypoxia alone and also combined with β2-agonists on the activity of the renin-angiotensin system. 2. In a double-blind crossover study, eight healthy subjects were randomized to inhale a hypoxic (FiO2 = 12%) or normoxic mixture for a period of 30 min, with either nebulized salbutamol (5 mg) or placebo administered into the circuit after 10 min. Plasma renin, angiotensin II and serum angiotensin-converting enzyme were measured at baseline and at intervals up to 2 h. Pulse rate and oxygen saturation were monitored continuously throughout the study. 3. After hypoxia alone, there was no change in the levels of plasma renin or angiotensin II. When salbutamol was added to the hypoxic mixture, there was a significant rise in plasma renin and angiotensin II [mean (SEM) maximal increase in angiotensin II of 5.6 (2.9)pg/ml and renin of 15.5 (6.3) μ-units/ml at 60 min, P < 0.05 compared with normoxia]. When salbutamol was administered in the normoxic mixture, plasma renin and angiotensin II also increased but this effect was similar to the effect of salbutamol in the hypoxic mixture. Serum angiotensin-converting enzyme levels were unaffected by hypoxia or salbutamol. 4. We conclude from these results that there is activation of the renin—angiotensin system in healthy subjects by salbutamol, but not hypoxia. In addition, the effect of salbutamol on the renin—angiotensin system is not influenced by the presence of hypoxia. As similar levels of hypoxia occur in acute exacerbations of asthma, it seems unlikely that hypoxia is contributing to activation of the renin—angiotensin system in acute severe asthma.

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.

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.

Anti-Hypertensive Effect of Water Extract of Danshen on Renovascular Hypertension Through Inhibition of the Renin Angiotensin System

2002 ◽  
Vol 30 (01) ◽  
pp. 87-93 ◽  
Author(s):  
Dae Gill Kang ◽  
Yong Gab Yun ◽  
Jang Hyun Ryoo ◽  
Ho Sub Lee
Keyword(s):  
Plasma Concentration ◽  
Water Extract ◽  
Renin Angiotensin System ◽  
Plasma Renin ◽  
Dependent Manner ◽  
Converting Enzyme ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Ace Activity ◽  
Dose Dependent

A study was designed to elucidate the mechanism of anti-hypertensive effects of Danshen in the two-kidney, one clip (2K1C) Goldblatt renovascular hypertensive model, which is the renin-angiotensin system (RAS)-dependent hypertensive model. We investigated the effects of water extracts of Danshen on the angiotensin converting enzyme (ACE) activities, systolic blood pressure (SBP), and hormone levels in the plasma of 2K1C rats. ACE activity was inhibited by the addition of Danshen extract in a dose-dependent manner. SBP was decreased significantly after administration of Danshen extract in 2K1C, whereas plasma renin activity (PRA) was not changed. The plasma concentration of aldosterone (PAC) was decreased significantly in 2K1C group administered with Danshen extract, whereas the plasma concentration of ANP was increased by administration of Danshen extract for three weeks. These results suggest that Danshen has an anti-hypertensive effect through the inhibition of ACE, an essential regulatory enzyme of RAS.

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.

Sign in / Sign up

Export Citation Format

Share Document