Abstract P104: Renin Angiotensin System (RAS) Modulation in Hypertension Program by Maternal Intrauterine Malnutrition

Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Rafael S Banti ◽  
Rodrigo Yokota ◽  
Danielle S Aragão ◽  
Adriana Souza ◽  
Amanda Pedroso ◽  
...  

Intrauterine malnutrition (IM) during the early stages of development can alter the function of organs and tissues and can predict a lifetime of increased risk for adverse health outcomes, such as diabetes and hypertension. The kidney plays a key role in the development of hypertension programmed by IM, with the participation of the RAS. Our objectives were to study ACE activity and angiotensin peptides levels in tissues. Pregnants Wistar rats were separated into two groups: control group (C), fed ad libitum, and malnourished group (D) submitted to food restriction (diet 50% of the amount of feed consumed by the group C). After birth the offspring were kept as experimental groups C and D, respectively. At 4 months of age, the animals were sacrificed, heart and kidney tissues were collected to quantify angiotensin peptides and ACE activity. The offspring born with low birth weight. Kidney ACE activity was higher in group D compared to group C (299 ±86.7 vs. 253.4 ±84.82 mU/mg, p<0.05), differing from Heart (D versus C: 0.15 ± 0.08 vs. 0.24 ±0.09 mU/mg). Group D presented high blood pressure values compared to group C (140.6 ±2.8 vs. 124,3±2.6 mmHg). Kidney and heart Ang II levels were increased in group D being significant when compared to group C (238.26 ±25.1 vs. 161.85 ±45.6 pmol/g and 397.89±74.9 vs. 223.33±48.7 pmol/g, p<0.05, respectively). The same was observed for Ang I. The vasodilator peptide Ang1-7 levels in group D from kidney and heart were lower in comparison with group C, thus emphasizing an enabling environment for hypertension (220.74 ± 48.74 vs. 288.09 ± 47 pmol/g and 152.1±41.2 pmol/g vs. 228.93±41.2 pmol/g, p<0.05, respectively). Our results indicate that perturbed maternal nutritional status alters tissue RAS resulting in higher blood pressure in the offspring, demonstrated by increased renal ACE activity and Ang II levels, with reduced Ang 1-7. The increase of Ang I and II in the heart, despite low ACE activity in this tissue suggests the activation of RAS alternative pathways. This study describes for the first time that low levels of Ang 1-7 contributed to the early development of hypertension.

2002 ◽  
Vol 283 (5) ◽  
pp. F995-F1002 ◽  
Author(s):  
Catherine Ingert ◽  
Michèle Grima ◽  
Catherine Coquard ◽  
Mariette Barthelmebs ◽  
Jean-Louis Imbs

Renin (RA) and angiotensin-converting enzyme (ACE) activities and angiotensinogen, ANG I, and ANG II levels were measured in the kidney (cortex and medulla) and plasma of Wistar-Kyoto rats on a low-sodium (LS; 0.025% NaCl; n= 8), normal-sodium (NS; 1% NaCl; n = 7), or high-sodium (HS; 8% NaCl; n = 7) diet for 21 days. RA, ANG I, and ANG II levels increased in a manner inversely related to sodium content of the diet in both plasma and renal tissues. The LS diet resulted in a 16-, 2.8-, and 1.8-fold increase in plasma RA, ANG I, and ANG II levels, respectively, compared with those in HS rats. In the renal cortex and medulla, RA, ANG I, and ANG II levels were also increased by diminution of dietary salt content but, in contrast to plasma, ANG II levels increased much more than RA or ANG I levels [5.4 (cortex)- and 4.7 (medulla)-fold compared with HS rats]. In summary, we demonstrated variations of ANG II levels in the kidney during dietary salt modifications. Our results confirm that RA and ACE activity are not the steps limiting intrarenal ANG II levels. Nevertheless, despite RA and ACE activity differences between renal cortex and medulla, ANG I and ANG II levels are equivalent in these two tissues; these results argue against a compartmentalization of RAS in these two intrarenal areas.


2015 ◽  
Vol 21 (3) ◽  
pp. 173-177 ◽  
Author(s):  
Rita de Cassia Marqueti ◽  
Nara Yumi Hashimoto ◽  
João Luiz Quaglioti Durigan ◽  
Lívia Larissa Batista e Silva ◽  
Jeeser Alves de Almeida ◽  
...  

INTRODUCTION: The renin-angiotensin system (RAS) has been associated with several biological processes of the human body, regulating, among others blood pressure and water and electrolytes balance. Moreover, RAS also regulates connective tissue growth. Recently, studies have shown that the use of nandrolone modifies the angiotensin-I converting enzyme (ACE) activity and increases collagen deposition in the heart. OBJECTIVE: The aim of study was to evaluate the Angiotensin-I converting enzyme (ACE) activity in the superficial flexor tendon (SFT) and in serum after load exercise in combination with anabolic androgenic steroid (AAS) administration after training session and six weeks of detraining. METHODS: Forty-eight Wistar rats were used into two groups (G1 and G2) subdivided into four subgroups: Sedentary (S); trained (T); AAS-treated (Deca-Durabolin(r), 5mg/kg, twice a week) sedentary rats (AAS) and AAS-treated and trained animals (AAST). Trained groups performed jumps in water: four series of 10 jumps each, followed by a 30 sec interval between the series, for seven weeks. RESULTS: Training increased ACE activity in the SFT compared to the control group (p <0.05). Both AAS and AAST groups presented higher ACE activity levels (p < 0.05). The AAST increased the ACE activity only compared to the trained animals. Only the AAST group presented significant higher levels of ACE in the serum. In the G2 group, all experimental groups presented decreased ACE activity in the serum and in the tendon, as compared to the control group. CONCLUSION: This study indicates that AAS administration and its combination with exercise increased ACE activity of tendons. AAS abuse could compromise tendon adaptation causing maladaptive remodeling.


Author(s):  
Kaiming Wang ◽  
Mahmoud Gheblawi ◽  
Anish Nikhanj ◽  
Matt Munan ◽  
Erika MacIntyre ◽  
...  

ACE (angiotensin-converting enzyme)-2 as the target for SARS-CoV-2 also negatively regulates the renin-angiotensin system. Pathological activation of ADAM17 (A disintegrin and metalloproteinase-17) may potentiate inflammation and diminish ACE2-mediated tissue protection through proteolytic shedding, contributing to SARS-CoV-2 pathogenesis. We aim to examine plasma soluble ACE2 and angiotensin profiles in relation to outcomes by enrolling consecutive patients admitted for COVID-19 with baseline blood collection at admission and repeated sampling at 7 days. The primary outcome was 90-day mortality, and secondary outcomes were the incidence of end-organ injuries. Overall, 242 patients were included, the median age was 63 (52–74) years, 155 (64.0%) were men, and 57 (23.6%) patients reached the primary end point. Baseline soluble ACE2 was elevated in COVID-19 but was not associated with disease severity or mortality. In contrast, an upward trajectory of soluble ACE2 at repeat sampling was independently associated with an elevated risk of mortality and incidence of acute myocardial injury and circulatory shock. Similarly, an increase in soluble tumor necrosis factor receptor levels was also associated with adverse outcomes. Plasma Ang I, Ang 1-7 (angiotensin 1–7) levels, and the Ang 1-7/Ang II (angiotensin II) ratio were elevated during SARS-CoV-2 infection related to downregulation of ACE activity at baseline. Moreover, patients having an upward trajectory of soluble ACE2 were characterized by an imbalance in the Ang 1-7/Ang II ratio. The observed dysregulation of ACE2 and angiotensin peptides with disease progression suggest a potential role of ADAM17 inhibition and enhancing the beneficial Ang 1-7/Mas axis to improve outcomes against SARS-CoV-2 infection.


2020 ◽  
Vol 71 (6) ◽  
pp. 307-311
Author(s):  
Sorin Ungurianu ◽  
Constantin Trus ◽  
Roxana-Rosmary Enciu

It is already known from a variety of previous reports that an independent brain renin�angiotensin system (RAS) exists, completely separated from the one in the periphery. This independent brain RAS has all the precursors and the enzymatic structures necessary for the generation of the angiotensin peptides. Thus, in the last few years various groups started focusing on the more central effects of less known angiotensins (e.g in comparison with Angiotensin (Ang) II), namely Ang III, Ang IV, Ang-(1�7) or Ang 5-8. One of these newly emerging angiotensins which has become an increased center of interest in many studies is Ang-(1-7), which is a heptapeptide previously described especially for its opposite effects to Ang II, in the peripheral vascular area, but also described for some opposite central functions vs. Ang II. These aspects are completed with the fact that it was recently suggested that the renin�angiotensin system could modulate the oxidative stress metabolism, and also it seems that the manifestations of Angiotensin-(1-7) on the basal oxidative stress status are contradictory, with a variety of reports describing controversial (e.g. both pro-oxidant and antioxidant actions) effects for this heptapeptide. Our results presented here are confirming a possible antioxidant effect of Ang-(1�7) administration on rat, as shown by the increased levels of antioxidant enzymes from the temporal lobe (superoxide dismutase and glutathione peroxidase) and decreased levels of malondialdehyde, as an important lipid peroxidation parameter.


1989 ◽  
Vol 67 (6) ◽  
pp. 656-662 ◽  
Author(s):  
Melvin J. Fregly ◽  
Colin Sumners ◽  
J. Robert Cade

Chronic dietary administration of L-tryptophan at 2.5 and 5.0% by weight reduced the elevated systolic blood pressure of spontaneously hypertensive (SH) rats. Blood pressure was reduced significantly by 3 weeks after initiation of treatment and continued to fall during the course of the 15 weeks of treatment. Body weights of the treated rats were not affected significantly by treatment, nor were daily food and fluid intakes and urine outputs. SH rats, treated with the higher dose of tryptophan, also significantly reduced their urinary outputs of epinephrine and norepinephrine compared with SH controls, while both doses of tryptophan increased urinary outputs of dopamine significantly above that of SH controls. Treatment with tryptophan increased significantly the specific binding of [125I]angiotensin II (Ang II) to membranes from the diencephalon in a dose-dependent manner. Measurement of catecholamine concentration of the supernatant from homogenates used for the Ang II binding assay revealed a significant correlation between the specific binding of Ang II to brain membranes of the two tryptophan-treated groups and the concentration of norepinephrine in the supernatant. There was also a significant correlation between the specific binding of Ang II and the concentratiion of dopamine in the supernatant of the control group and the group treated with the higher dose of tryptophan. These results show that chronic dietary administration of tryptophan can reduce the elevated blood pressure of SH rats and support the possibility that this neutral amino acid may act via its effect on the concentration of the neurohormones, norepinephrine and dopamine, in the diencephalon to regulate the binding of Ang II to its receptors.Key words: tryptophan, spontaneous hypertension, brain angiotensin binding, urinary catecholamines.


2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Vitor M Rocha ◽  
Maria Guadalupe B Pippa

Backgroung: Rheumatoid arthritis (RA) is a chronic systemic inflammatory disease, that appear to be responsible for 50% of mortality for thrombotic events such as Myocardial Infarction (MI) and Ischemic Stroke (SI) in RA patients. Occur approximately a decade earlier in these patients compared with the normal population. Objectives: To determine the risk of developing cardiovascular disease in patients with Rheumatoid Arthritis according to the classification criteria of the American College of Rheumatology. Methods: To assess the risk of cardiovascular diseases we studied 78 patients diagnosed with Rheumatoid Arthritis. For this we used the criteria of the risk score of Acute Coronary Disease in 10 years according to the Framingham Heart Study. A control group consisted of 21 patients with osteoarthritis and fibromyalgia was also assessed using the same criteria, where age, sex, systolic blood pressure values, total cholesterol, cholesterol HDL, presence of smoking and diagnosis of diabetes, were scored. Results: Patients with rheumatoid arthritis had a mean disease duration of 12.8 years (SD=7.4), age 58.6 years (SD=10.3) and the control group 59.3 years (SD=10,0). The old values of total cholesterol, HDL, blood pressure and being with Diabetes Mellitus showed positive correlations with the Cardiovascular Risk, and Blood Pressure in the index this correlation was stronger (r=+0.593) in Rheumatoid Arthritis and age (r=+0.702) in the control group. The Global Cardiovascular Risk in each group were considered low (7,8 points to Rematoid Artrhrits and 9,3 points to the control group). Conclusion: The results showed no increased risk of cardiovascular disease when compared to control group. Remember that control group fact be constituted by a larger number of diabetics, which likely impact these results.


Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Xiao C Li ◽  
Ana P Leite ◽  
Liang Zhang ◽  
Jia L Zhuo

The present study tested the hypothesis that intratubular angiotensin II (Ang II) and AT 1a receptors in the proximal tubules of the kidney plays an important role in basal blood pressure control and in the development of Ang II-induced hypertension. Mutant mice with proximal tubule-specific deletion of AT 1a receptors in the kidney, PT- Agtr1a -/- , were generated to test the hypothesis. Eight groups (n=7-12 per group) of adult male wild-type (WT) and PT- Agtr1a -/- mice were infused with or without Ang II for 2 weeks (1.5 mg/kg, i.p.). Basal systolic, diastolic, and mean arterial pressures were ~13 ± 3 mmHg lower in PT- Agtr1a -/- than WT mice ( P <0.01). Basal glomerular filtration rate (GFR), as measured using transdermal FITC-sinistrin, was significantly higher in PT- Agtr1a -/- mice (WT: 160.4 ± 7.0 μl/min vs. PT- Agtr1a -/- : 186.0 ± 6.0 μl/min, P <0.05). Basal 24 h urinary Na + excretion (U Na V) was significantly higher in PT- Agtr1a -/- than WT mice ( P <0.01). In response to Ang II infusion, both WT and PT- Agtr1a -/- mice developed hypertension, and the magnitude of the pressor response to Ang II was similar in WT (Δ43 ± 3 mmHg, P <0.01) and PT- Agtr1a -/- mice (Δ39 ± 5 mmHg, P <0.01). However, the absolute blood pressure level was still 16 ± 3 mmHg lower in PT- Agtr1a -/- mice ( P <0.01). Ang II significantly decreased GFR to 132.2 ± 7.0 μl/min in WT mice ( P <0.01), and to 129.4 ± 18.6 μl/min in PT- Agtr1a -/- mice ( P <0.01), respectively. In WT mice, U Na V increased from 139.3 ± 22.3 μmol/24 h in the control group to 196.4 ± 29.6 μmol/24 h in the Ang II-infused group ( P <0.01). In PT- Agtr1a -/- mice, U Na V increased from 172.0 ± 10.2 μmol/24 h in the control group to 264.7 ± 35.4 μmol/24 h in the Ang II-infused group ( P <0.01). The pressor response to Ang II was attenuated, while the natriuretic response was augmented by losartan in WT and PT- Agtr1a -/- mice ( P <0.01). Finally, proximal tubule-specific deletion of AT 1a receptors significantly augmented the pressure-natriuresis response and natriuretic responses to acute saline infusion ( P <0.01) or a 2% high salt diet ( P <0.01). We concluded that deletion of AT 1a receptors selectively in the proximal tubules lowers basal blood pressure and attenuates Ang II-induced hypertension by increasing GFR and promoting the natriuretic response in PT- Agtr1a -/- mice.


1990 ◽  
Vol 259 (2) ◽  
pp. H543-H553
Author(s):  
R. D. Randall ◽  
B. G. Zimmerman

Rabbits were bilaterally nephrectomized for 24 h or received an angiotensin-converting enzyme (ACE) inhibitor chronically (5 days) before an acute experiment. Conductance responses to sympathetic nerve stimulation (SNS) (0.25, 0.75, and 2.25 Hz) and norepinephrine (NE) administration (0.2, 0.6, and 1.8 micrograms ia) were determined from simultaneous blood pressure and iliac blood flow measurements. Conductance responses to SNS were significantly reduced in nephrectomized (44, 26, and 20%) and chronic ACE inhibition (39, 31, and 24%) groups compared with normal controls, whereas conductance responses to NE were unchanged. Continuous infusion of angiotensin II (ANG II) for 24 h restored the depressed responses to SNS in nephrectomized and chronic ACE inhibition groups compared with normal controls but did not change conductance responses to NE. Acute ACE inhibition did not affect the conductance responses to SNS or NE compared with controls. Vascular tissue ACE activity was inhibited to a similar degree (50%) in both acute and chronic ACE inhibition groups compared with normal rabbits. Sodium depletion increased the conductance responses to SNS (30 and 24% at 0.25 and 0.75 Hz, respectively), but responses to NE were not affected. Chronic ACE inhibition significantly attenuated the conductance responses to SNS and slightly decreased responses to NE in sodium-depleted rabbits. Thus, in the anesthetized rabbit, the renin-angiotensin system potentiates the effect of SNS, presumably by ANG II acting at a prejunctional site, and this effect of ANG II appears to be long term in nature. Therefore, the renin-angiotensin system exerts a physiological role in the control of blood pressure in addition to the ability of this system to support arterial pressure in pathophysiological states.


2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Areeg E. Elemam ◽  
Nisreen D. Omer ◽  
Neima M. Ibrahim ◽  
Ahmed B. Ali

Background. The current study investigated the effect of dipping tobacco (DT) use on arterial wall stiffness which is a known marker of increased risk of cardiovascular events. Methods. A case-control study which included 101 adult males was carried out in Al-Shaab Teaching Hospital. Blood pressure and pulse wave analysis parameters were recorded in 51 DT users (study group) before and after 30 minutes of placing tobacco and in 50 nontobacco users (control group). Anthropometric measurements were collected using data collection sheet. Data were entered into a computer and analyzed by using the software Statistical Package for the Social Sciences (SPSS) version 20 (SPSS Inc., Chicago, IL, USA). Results. At baseline measurements, heart rate (HR) was significantly lower in the study group compared to the control group ( 66.15 ± 9.21 vs. 72.87 ± 10.13 beats/min; P value ≤ 0.001). Subendocardial viability ratio (SEVR) was significantly higher in the study group compared to the control group ( 203.44 ± 30.34 vs. 179.11 ± 30.51 % ; P value ≤ 0.001). Acute effects of DT compared to pretobacco dipping showed significant increase in HR ( 72.50 ± 10.89 vs. 66.15 ± 9.21 beats/min; P value ≤ 0.001) and significant decrease in augmentation pressure (AP) (4.30 (2.30-8.00) vs. 3.30 (0.60-6.3) mmHg; P value ≤ 0.001), ejection duration (ED) ( 271.65 ± 19.42 vs. 279.53 ± 20.47   ms ; P value ≤ 0.001), and SEVR ( 187.11 ± 29.81 vs. 203.44 ± 30.34 ; P value ≤ 0.001). Linear regression analysis for AP predictor showed that only HR and AIx@75 affect and predict the values of AP ( Beta ± SE ; − 0.242 ± 0.019 , P value ≤ 0.001; 0.685 ± 0.014 , P value ≤ 0.001). Conclusions. Long-term use of DT was not associated with permanent changes in heart rate and blood pressure. Acute tobacco dipping caused an acute increase in heart rate and oxygen demands of myocardium.


2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Yunzhao Yang ◽  
Shaoqun Tang ◽  
Chunchun Zhai ◽  
Xin Zeng ◽  
Qingjian Liu ◽  
...  

Background. Multiple interleukin (IL) family members were reported to be closely related to hypertension. We aimed to investigate whether IL-9 affects angiotensin II- (Ang II-) induced hypertension in mice. Methods. Mice were treated with Ang II, and IL-9 expression was determined. In addition, effects of IL-9 knockout (KO) on blood pressure were observed in Ang II-infused mice. To determine whether the effects of IL-9 on blood pressure was mediated by the signal transducer and activator of the transcription 3 (STAT3) pathway, Ang II-treated mice were given S31-201. Furthermore, circulating IL-9 levels in patients with hypertension were measured. Results. Ang II treatment increased serum and aortic IL-9 expression in a dose-dependent manner; IL-9 levels were the highest in the second week and continued to remain high into the fourth week after the treatment. IL-9 KO downregulated proinflammatory cytokine expression, whereas it upregulated anti-inflammatory cytokine levels, relieved vascular dysfunction, and decreased blood pressure in Ang II-infused mice. IL-9 also reduced smooth muscle 22α (SM22α) expression and increased osteopontin (OPN) levels both in mice and in vitro. The effects of IL-9 KO on blood pressure and inflammatory response were significantly reduced by S31-201 treatment. Circulating IL-9 levels were significantly increased in patients with the hypertension group than in the control group, and elevated IL-9 levels positively correlated with both systolic blood pressure and diastolic blood pressure in patients with hypertension. Conclusions. IL-9 KO alleviates inflammatory response, prevents phenotypic transformation of smooth muscle, reduces vascular dysfunction, and lowers blood pressure via the STAT3 pathway in Ang II-infused mice. IL-9 might be a novel target for the treatment and prevention of clinical hypertension.


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