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Panariello F, Cellini L, Speciani M, De Ronchi D, Atti AR. How Does SARS-CoV-2 Affect the Central Nervous System? A Working Hypothesis. Front Psychiatry 2020; 11:582345. [PMID: 33304284 PMCID: PMC7701095 DOI: 10.3389/fpsyt.2020.582345] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Accepted: 10/07/2020] [Indexed: 12/15/2022] Open
Abstract
Interstitial pneumonia was the first manifestation to be recognized as caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); however, in just a few weeks, it became clear that the coronavirus disease-2019 (COVID-19) overrun tissues and more body organs than just the lungs, so much so that it could be considered a systemic pathology. Several studies reported the involvement of the conjunctiva, the gut, the heart and its pace, and vascular injuries such as thromboembolic complications and Kawasaki disease in children and toddlers were also described. More recently, it was reported that in a sample of 214 SARS-CoV-2 positive patients, 36.4% complained of neurological symptoms ranging from non-specific manifestations (dizziness, headache, and seizures), to more specific symptoms such hyposmia or hypogeusia, and stroke. Older individuals, especially males with comorbidities, appear to be at the highest risk of developing such severe complications related to the Central Nervous System (CNS) involvement. Neuropsychiatric manifestations in COVID-19 appear to develop in patients with and without pre-existing neurological disorders. Growing evidence suggests that SARS-CoV-2 binds to the human Angiotensin-Converting Enzyme 2 (ACE2) for the attachment and entrance inside host cells. By describing ACE2 and the whole Renin Angiotensin Aldosterone System (RAAS) we may better understand whether specific cell types may be affected by SARS-CoV-2 and whether their functioning can be disrupted in case of an infection. Since clear evidences of neurological interest have already been shown, by clarifying the topographical distribution and density of ACE2, we will be able to speculate how SARS-CoV-2 may affect the CNS and what is the pathogenetic mechanism by which it contributes to the specific clinical manifestations of the disease. Based on such evidences, we finally hypothesize the process of SARS-CoV-2 invasion of the CNS and provide a possible explanation for the onset or the exacerbation of some common neuropsychiatric disorders in the elderly including cognitive impairment and Alzheimer disease.
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Affiliation(s)
- Fabio Panariello
- Department of Mental Health, Local Health Authorities, Bologna, Italy
| | - Lorenzo Cellini
- Department of Biomedical and Neuromotor Sciences, Psychiatry, Bologna University, Bologna, Italy
| | - Maurizio Speciani
- Department of Biomedical and Neuromotor Sciences, Psychiatry, Bologna University, Bologna, Italy
| | - Diana De Ronchi
- Department of Biomedical and Neuromotor Sciences, Psychiatry, Bologna University, Bologna, Italy
| | - Anna Rita Atti
- Department of Biomedical and Neuromotor Sciences, Psychiatry, Bologna University, Bologna, Italy
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Abate G, Memo M, Uberti D. Impact of COVID-19 on Alzheimer's Disease Risk: Viewpoint for Research Action. Healthcare (Basel) 2020; 8:E286. [PMID: 32839380 PMCID: PMC7551579 DOI: 10.3390/healthcare8030286] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 08/14/2020] [Accepted: 08/18/2020] [Indexed: 12/11/2022] Open
Abstract
In the middle of the coronavirus disease 19 (COVID-19) outbreak, the main efforts of the scientific community are rightly all focused on identifying efficient pharmacological treatments to cure the acute severe symptoms and developing a reliable vaccine. On the other hand, we cannot exclude that, in Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) positive subjects, the virus infection could have long-term consequences, leading to chronic medical conditions such as dementia and neurodegenerative disease. Considering the age of SARS-CoV-2 infected subjects, the neuroinvasive potential might lead/contribute to the development of neurodegenerative diseases. Here, we analyzed a possible link between SARS-CoV-2 infection and Alzheimer's disease risk, hypothesizing possible mechanisms at the base of disease development. This reflection raises the need to start to experimentally investigating today the mechanistic link between Alzheimer's disease (AD) and COVID-19 to be ready tomorrow.
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Affiliation(s)
- Giulia Abate
- Department of Molecular and Translational Medicine, University of Brescia, 25123 Brescia, Italy; (M.M.); (D.U.)
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Santos RAS, Sampaio WO, Alzamora AC, Motta-Santos D, Alenina N, Bader M, Campagnole-Santos MJ. The ACE2/Angiotensin-(1-7)/MAS Axis of the Renin-Angiotensin System: Focus on Angiotensin-(1-7). Physiol Rev 2018; 98:505-553. [PMID: 29351514 PMCID: PMC7203574 DOI: 10.1152/physrev.00023.2016] [Citation(s) in RCA: 683] [Impact Index Per Article: 113.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
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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Affiliation(s)
- Robson Augusto Souza Santos
- National Institute of Science and Technology in Nanobiopharmaceutics, Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais , Belo Horizonte , Brazil ; Department of Biological Sciences, Federal University of Ouro Preto , Ouro Preto , Brazil ; Max-Delbrück-Center for Molecular Medicine (MDC), Berlin , Germany ; Berlin Institute of Health (BIH), Berlin , Germany ; Charité - University Medicine, Berlin , Germany ; DZHK (German Center for Cardiovascular Research), Partner Site Berlin, Berlin , Germany ; Institute for Biology, University of Lübeck , Lübeck , Germany
| | - Walkyria Oliveira Sampaio
- National Institute of Science and Technology in Nanobiopharmaceutics, Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais , Belo Horizonte , Brazil ; Department of Biological Sciences, Federal University of Ouro Preto , Ouro Preto , Brazil ; Max-Delbrück-Center for Molecular Medicine (MDC), Berlin , Germany ; Berlin Institute of Health (BIH), Berlin , Germany ; Charité - University Medicine, Berlin , Germany ; DZHK (German Center for Cardiovascular Research), Partner Site Berlin, Berlin , Germany ; Institute for Biology, University of Lübeck , Lübeck , Germany
| | - Andreia C Alzamora
- National Institute of Science and Technology in Nanobiopharmaceutics, Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais , Belo Horizonte , Brazil ; Department of Biological Sciences, Federal University of Ouro Preto , Ouro Preto , Brazil ; Max-Delbrück-Center for Molecular Medicine (MDC), Berlin , Germany ; Berlin Institute of Health (BIH), Berlin , Germany ; Charité - University Medicine, Berlin , Germany ; DZHK (German Center for Cardiovascular Research), Partner Site Berlin, Berlin , Germany ; Institute for Biology, University of Lübeck , Lübeck , Germany
| | - Daisy Motta-Santos
- National Institute of Science and Technology in Nanobiopharmaceutics, Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais , Belo Horizonte , Brazil ; Department of Biological Sciences, Federal University of Ouro Preto , Ouro Preto , Brazil ; Max-Delbrück-Center for Molecular Medicine (MDC), Berlin , Germany ; Berlin Institute of Health (BIH), Berlin , Germany ; Charité - University Medicine, Berlin , Germany ; DZHK (German Center for Cardiovascular Research), Partner Site Berlin, Berlin , Germany ; Institute for Biology, University of Lübeck , Lübeck , Germany
| | - Natalia Alenina
- National Institute of Science and Technology in Nanobiopharmaceutics, Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais , Belo Horizonte , Brazil ; Department of Biological Sciences, Federal University of Ouro Preto , Ouro Preto , Brazil ; Max-Delbrück-Center for Molecular Medicine (MDC), Berlin , Germany ; Berlin Institute of Health (BIH), Berlin , Germany ; Charité - University Medicine, Berlin , Germany ; DZHK (German Center for Cardiovascular Research), Partner Site Berlin, Berlin , Germany ; Institute for Biology, University of Lübeck , Lübeck , Germany
| | - Michael Bader
- National Institute of Science and Technology in Nanobiopharmaceutics, Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais , Belo Horizonte , Brazil ; Department of Biological Sciences, Federal University of Ouro Preto , Ouro Preto , Brazil ; Max-Delbrück-Center for Molecular Medicine (MDC), Berlin , Germany ; Berlin Institute of Health (BIH), Berlin , Germany ; Charité - University Medicine, Berlin , Germany ; DZHK (German Center for Cardiovascular Research), Partner Site Berlin, Berlin , Germany ; Institute for Biology, University of Lübeck , Lübeck , Germany
| | - Maria Jose Campagnole-Santos
- National Institute of Science and Technology in Nanobiopharmaceutics, Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais , Belo Horizonte , Brazil ; Department of Biological Sciences, Federal University of Ouro Preto , Ouro Preto , Brazil ; Max-Delbrück-Center for Molecular Medicine (MDC), Berlin , Germany ; Berlin Institute of Health (BIH), Berlin , Germany ; Charité - University Medicine, Berlin , Germany ; DZHK (German Center for Cardiovascular Research), Partner Site Berlin, Berlin , Germany ; Institute for Biology, University of Lübeck , Lübeck , Germany
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Cerrato BD, Carretero OA, Janic B, Grecco HE, Gironacci MM. Heteromerization Between the Bradykinin B2 Receptor and the Angiotensin-(1-7) Mas Receptor: Functional Consequences. Hypertension 2016; 68:1039-48. [PMID: 27550920 DOI: 10.1161/hypertensionaha.116.07874] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 07/26/2016] [Indexed: 12/20/2022]
Abstract
Bradykinin B2 receptor (B2R) and angiotensin-(1-7) Mas receptor (MasR)-mediated effects are physiologically interconnected. The molecular basis for such cross talk is unknown. It is hypothesized that the cross talk occurs at the receptor level. We investigated B2R-MasR heteromerization and the functional consequences of such interaction. B2R fused to the cyan fluorescent protein and MasR fused to the yellow fluorescent protein were transiently coexpressed in human embryonic kidney293T cells. Fluorescence resonance energy transfer analysis showed that B2R and MasR formed a constitutive heteromer, which was not modified by their agonists. B2R or MasR antagonists decreased fluorescence resonance energy transfer efficiency, suggesting that the antagonist promoted heteromer dissociation. B2R-MasR heteromerization induced an 8-fold increase in the MasR ligand-binding affinity. On agonist stimulation, the heteromer was internalized into early endosomes with a slower sequestration rate from the plasma membrane, compared with single receptors. B2R-MasR heteromerization induced a greater increase in arachidonic acid release and extracellular signal-regulated kinase phosphorylation after angiotensin-(1-7) stimulation, and this effect was blocked by the B2R antagonist. Concerning serine/threonine kinase Akt activity, a significant bradykinin-promoted activation was detected in B2R-MasR but not in B2R-expressing cells. Angiotensin-(1-7) and bradykinin elicited antiproliferative effects only in cells expressing B2R-MasR heteromers, but not in cells expressing each receptor alone. Proximity ligation assay confirmed B2R-MasR interaction in human glomerular endothelial cells supporting the interaction between both receptors in vivo. Our findings provide an explanation for the cross talk between bradykinin B2R and angiotensin-(1-7) MasR-mediated effects. B2R-MasR heteromerization induces functional changes in the receptor that may lead to long-lasting protective properties.
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Affiliation(s)
- Bruno D Cerrato
- From the Departamento de Química Biológica, IQUIFIB-CONICET, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Argentina (B.D.C., M.M.G.); Hypertension and Vascular Research Division, Henry Ford Hospital, Detroit, MI (O.A.C., B.J.); and Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA-CONICET, Argentina (H.E.G)
| | - Oscar A Carretero
- From the Departamento de Química Biológica, IQUIFIB-CONICET, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Argentina (B.D.C., M.M.G.); Hypertension and Vascular Research Division, Henry Ford Hospital, Detroit, MI (O.A.C., B.J.); and Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA-CONICET, Argentina (H.E.G)
| | - Brana Janic
- From the Departamento de Química Biológica, IQUIFIB-CONICET, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Argentina (B.D.C., M.M.G.); Hypertension and Vascular Research Division, Henry Ford Hospital, Detroit, MI (O.A.C., B.J.); and Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA-CONICET, Argentina (H.E.G)
| | - Hernán E Grecco
- From the Departamento de Química Biológica, IQUIFIB-CONICET, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Argentina (B.D.C., M.M.G.); Hypertension and Vascular Research Division, Henry Ford Hospital, Detroit, MI (O.A.C., B.J.); and Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA-CONICET, Argentina (H.E.G)
| | - Mariela M Gironacci
- From the Departamento de Química Biológica, IQUIFIB-CONICET, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Argentina (B.D.C., M.M.G.); Hypertension and Vascular Research Division, Henry Ford Hospital, Detroit, MI (O.A.C., B.J.); and Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA-CONICET, Argentina (H.E.G).
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Keaney JJ, Groarke JD, Galvin Z, McGorrian C, McCann HA, Sugrue D, Keelan E, Galvin J, Blake G, Mahon NG, O'Neill J. The Brady Bunch? New evidence for nominative determinism in patients' health: retrospective, population based cohort study. BMJ 2013; 347:f6627. [PMID: 24336304 PMCID: PMC3898418 DOI: 10.1136/bmj.f6627] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVE To ascertain whether a name can influence a person's health, by assessing whether people with the surname "Brady" have an increased prevalence of bradycardia. DESIGN Retrospective, population based cohort study. SETTING One university teaching hospital in Dublin, Ireland. PARTICIPANTS People with the surname "Brady" in Dublin, determined through use of an online telephone directory. MAIN OUTCOME MEASURE Prevalence of participants who had pacemakers inserted for bradycardia between 1 January 2007 and 28 February 2013. RESULTS 579 (0.36%) of 161,967 people who were listed on the Dublin telephone listings had the surname "Brady." The proportion of pacemaker recipients was significantly higher among Bradys (n=8, 1.38%) than among non-Bradys (n=991, 0.61%; P=0.03). The unadjusted odds ratio (95% confidence interval) for pacemaker implantation among individuals with the surname Brady compared with individuals with other surnames was 2.27 (1.13 to 4.57). CONCLUSIONS Patients named Brady are at increased risk of needing pacemaker implantation compared with the general population. This finding shows a potential role for nominative determinism in health.
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Affiliation(s)
- John J Keaney
- Cardiology Department, Mater Misericordiae University Hospital, Dublin 7, Ireland
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Abstract
SIGNIFICANCE The renin-angiotensin system (RAS) plays an important role in the normal control of cardiovascular and renal function in the healthy state and is a contributing factor in the development and progression of various types of cardiovascular diseases (CVD), including hypertension, diabetes, and heart failure. RECENT ADVANCES Evidence suggests that a balance between activation of the ACE/Ang II/AT1 receptor axis and the ACE2/Ang-(1-7)/Mas receptor axis is important for the function of the heart, kidney, and autonomic nervous system control of the circulation in the normal healthy state. An imbalance in these opposing pathways toward the ACE/Ang II/AT1 receptor axis is associated with CVD. The key component of this imbalance with respect to neural control of the circulation is the negative interaction between oxidative and NO• mechanisms, which leads to enhanced sympathetic tone and activation in disease conditions such as hypertension and heart failure. CRITICAL ISSUES The key mechanisms that disrupt normal regulation of Ang II and Ang-(1-7) signaling and promote pathogenesis of CVD at all organ levels remain poorly understood. The reciprocal relation between ACE and ACE2 expression and function suggests they are controlled interdependently at pre- and post-translational levels. Insights from neural studies suggest that an interaction between oxidative and nitrosative pathways may be key. FUTURE DIRECTIONS The role of redox mechanisms in the control of expression and activity of RAS enzymes and Ang receptors may provide important insight into the function of local tissue RAS in health and disease.
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Affiliation(s)
- Kaushik P Patel
- 1 Department of Cellular and Integrative Physiology, University of Nebraska Medical Center , Omaha, Nebraska
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Jiang T, Gao L, Lu J, Zhang YD. ACE2-Ang-(1-7)-Mas Axis in Brain: A Potential Target for Prevention and Treatment of Ischemic Stroke. Curr Neuropharmacol 2013; 11:209-17. [PMID: 23997755 PMCID: PMC3637674 DOI: 10.2174/1570159x11311020007] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2012] [Revised: 09/12/2012] [Accepted: 10/08/2012] [Indexed: 12/20/2022] Open
Abstract
The renin-angiotensin system (RAS) in brain is a crucial regulator for physiological homeostasis and diseases of cerebrovascular system, such as ischemic stroke. Overactivation of brain Angiotensin-converting enzyme (ACE) - Angiotensin II (Ang II) - Angiotensin II type 1 receptor (AT1R) axis was found to be involved in the progress of hypertension, atherosclerosis and thrombogenesis, which increased the susceptibility to ischemic stroke. Besides, brain Ang II levels have been revealed to be increased in ischemic tissues after stroke, and contribute to neural damage through elevating oxidative stress levels and inducing inflammatory response in the ischemic hemisphere via AT1R. In recent years, new components of RAS have been discovered, including ACE2, Angiotensin-(1-7) [Ang-(1-7)] and Mas, which constitute ACE2-Ang-(1-7)-Mas axis. ACE2 converts Ang II to Ang-(1-7), and Ang-(1-7) binds with its receptor Mas, exerting benefical effects in cerebrovascular disease. Through interacting with nitric oxide and bradykinin, Ang-(1-7) could attenuate the development of hypertension and the pathologic progress of atherosclerosis. Besides, its antithrombotic activity also prevents thrombogenic events, which may contribute to reduce the risk of ischemic stroke. In addition, after ischemia insult, ACE2-Ang-(1-7)-Mas has been shown to reduce the cerebral infarct size and improve neurological deficits through its antioxidative and anti-inflammatory effects. Taken together, activation of the ACE2-Ang-(1-7)-Mas axis may become a novel therapeutic target in prevention and treatment of ischemia stroke, which deserves further investigations.
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Affiliation(s)
- Teng Jiang
- Department of Neurology, Nanjing First Hospital, Nanjing Medical University, Nanjing, P.R. China
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Tsuda K. Angiotensin-(1-7) in the central nervous system regulation of blood pressure and renin-angiotensin system. Am J Hypertens 2013; 26:1174. [PMID: 23939418 DOI: 10.1093/ajh/hpt102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Kazushi Tsuda
- Cardiovascular and Metabolic Research Center, Kansai University of Health Sciences, Osaka, Japan
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Tsuda K. Letter by Tsuda Regarding Article, “Impact of ACE2 Deficiency and Oxidative Stress on Cerebrovascular Function With Aging”. Stroke 2013; 44:e34. [DOI: 10.1161/strokeaha.111.000431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Kazushi Tsuda
- Cardiovascular and Metabolic Research CenterKansai University of Health SciencesOsaka, Japan
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Abstract
Ang-(1–7) [angiotensin-(1–7)] constitutes an important functional end-product of the RAS (renin–angiotensin system) endogenously formed from AngI (angiotensin I) or AngII (angiotensin II) through the catalytic activity of ACE2 (angiotensin-converting enzyme 2), prolyl carboxypeptidase, neutral endopeptidase or other endopeptidases. Ang-(1–7) lacks the pressor, dipsogenic or stimulatory effect on aldosterone release characteristic of AngII. In contrast, it produces vasodilation, natriuresis and diuresis, and inhibits angiogenesis and cell growth. At the central level, Ang-(1–7) acts at sites involved in the control of cardiovascular function, thus contributing to blood pressure regulation. This action may result from its inhibitory neuromodulatory action on NE [noradrenaline (norepinephrine)] levels at the synaptic cleft, i.e. Ang-(1–7) reduces NE release and synthesis, whereas it causes an increase in NE transporter expression, contributing in this way to central NE neuromodulation. Thus, by selective neurotransmitter release, Ang-(1–7) may contribute to the overall central cardiovascular effects. In the present review, we summarize the central effects of Ang-(1–7) and the mechanism by which the peptide modulates NE levels in the synaptic cleft. We also provide new evidences of its cerebroprotective role.
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Nautiyal M, Shaltout HA, de Lima DC, do Nascimento K, Chappell MC, Diz DI. Response to Angiotensin-(1-7) and Bradykinin in Baroreceptor Reflex Sensitivity in Hypertension. Hypertension 2013; 61:e20. [PMID: 23444463 DOI: 10.1161/hypertensionaha.111.00571] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Manisha Nautiyal
- Hypertension and Vascular Research CenterWake Forest University School of Medicine Winston-Salem, NC, USA
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Śleszyńska M, Wierzba TH, Malinowski K, Tůmová T, Lammek B, Slaninová J, Prahl A. Novel Bradykinin Analogues Modified in the N-Terminal Part of the Molecule with a Variety of Acyl Substituents. Int J Pept Res Ther 2012; 18:117-124. [PMID: 22593719 PMCID: PMC3332343 DOI: 10.1007/s10989-011-9285-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/14/2011] [Indexed: 12/03/2022]
Abstract
In the current work we present some pharmacological characteristics of ten new analogues of bradykinin (Arg–Pro–Pro–Gly–Phe–Ser–Pro–Phe–Arg) modified in the N-terminal part of the molecule with a variety of acyl substituents. Of the many acylating agents used previously with B2 receptor antagonists, the following residues were chosen: 1-adamantaneacetic acid (Aaa), 1-adamantanecarboxylic acid (Aca), 4-tert-butylbenzoic acid (t-Bba), 4-aminobenzoic acid (Aba), 12-aminododecanoic acid (Adc), succinic acid (Sua), 4-hydroxybenzoic acid, 4-hydroxy-3-methoxybenzoic acid, 3-(4-hydroxyphenyl)propionic acid and 6-hydroxy-2-naphthoic acid. Biological activity of the compounds was assessed in the in vivo rat blood pressure test and the in vitro rat uterus test. Surprisingly, N-terminal substitution of the bradykinin peptide chain itself with aforementioned groups resulted in antagonists of bradykinin in the pressor test and suppressed agonistic potency in the uterotonic test. These interesting findings need further studies as they can be helpful for designing more potent B2 receptor blockers.
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Affiliation(s)
- Małgorzata Śleszyńska
- Faculty of Chemistry, University of Gdańsk, Sobieskiego 18/19, 80-952 Gdańsk, Poland
| | - Tomasz H. Wierzba
- Department of Physiology, Medical University of Gdańsk, Dębinki 1, 80-211 Gdańsk, Poland
| | - Krzysztof Malinowski
- Department of Physiology, Medical University of Gdańsk, Dębinki 1, 80-211 Gdańsk, Poland
| | - Tereza Tůmová
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo sq. 2, 166 10 Prague 6, Czech Republic
| | - Bernard Lammek
- Faculty of Chemistry, University of Gdańsk, Sobieskiego 18/19, 80-952 Gdańsk, Poland
| | - Jiřina Slaninová
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo sq. 2, 166 10 Prague 6, Czech Republic
| | - Adam Prahl
- Faculty of Chemistry, University of Gdańsk, Sobieskiego 18/19, 80-952 Gdańsk, Poland
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Isa K, Arnold AC, Westwood BM, Chappell MC, Diz DI. Angiotensin-converting enzyme inhibition, but not AT(1) receptor blockade, in the solitary tract nucleus improves baroreflex sensitivity in anesthetized transgenic hypertensive (mRen2)27 rats. Hypertens Res 2011; 34:1257-62. [PMID: 21937997 PMCID: PMC4160904 DOI: 10.1038/hr.2011.110] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Transgenic hypertensive (mRen2)27 rats overexpress the murine Ren2 gene and have impaired baroreflex sensitivity (BRS) for control of the heart rate. Removal of endogenous angiotensin (Ang)-(1-7) tone using a receptor blocker does not further lower BRS. Therefore, we assessed whether blockade of Ang II with a receptor antagonist or combined reduction in Ang II and restoration of endogenous Ang-(1-7) levels with Ang-converting enzyme (ACE) inhibition will improve BRS in these animals. Bilateral solitary tract nucleus (nTS) microinjections of the AT(1) receptor blocker, candesartan (CAN, 24 pmol in 120 nl, n=9), or a peptidic ACE inhibitor, bradykinin (BK) potentiating nonapeptide (Pyr-Trp-Pro-Arg-Pro-Gln-Ile-Pro-Pro; BPP9α, 9 nmol in 60 nl, n=12), in anesthetized male (mRen2)27 rats (15-25 weeks of age) show that AT(1) receptor blockade had no significant effect on BRS, whereas microinjection of BPP9α improved BRS over 60-120 min. To determine whether Ang-(1-7) or BK contribute to the increase in BRS, separate experiments using the Ang-(1-7) receptor antagonist D-Ala(7)-Ang-(1-7) or the BK antagonist HOE-140 showed that only the Ang-(1-7) receptor blocker completely reversed the BRS improvement. Thus, acute AT(1) blockade is unable to reverse the effects of long-term Ang II overexpression on BRS, whereas ACE inhibition restores BRS over this same time frame. As the BPP9α potentiation of BK actions is a rapid phenomenon, the likely mechanism for the observed delayed increase in BRS is through ACE inhibition and elevation of endogenous Ang-(1-7).
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Affiliation(s)
- Katsunori Isa
- Hypertension and Vascular Research Center, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1032, USA
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Wehlage SJ, Smith FG. Nitric oxide and angiotensin II regulate cardiovascular homeostasis and the arterial baroreflex control of heart rate in conscious lambs. J Renin Angiotensin Aldosterone Syst 2011; 13:99-106. [DOI: 10.1177/1470320311423282] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
To investigate the potential role of angiotensin II (Ang II) type 1 receptors (AT1Rs) as well as endogenously produced nitric oxide (NO) in regulating cardiovascular homeostasis during ontogeny, experiments were carried out in conscious lambs aged approximately 1 week ( N = 9) and 6 weeks ( N = 11). The arterial baroreflex control of heart rate (HR) was assessed before and after intravenous (IV) infusion of the selective AT1R antagonist, ZD 7155, before and after IV administration of the L-arginine analogue, NG-nitro-L-arginine methyl ester (L-NAME). In both groups, after ZD 7155 alone, mean arterial pressure decreased then increased after L-NAME. At 1 but not 6 weeks, HR decreased after ZD 7155 as well as after L-NAME. At 1 but not 6 weeks, there was a decrease in the HR range after ZD 7155 and after ZD 7155 + L-NAME, as compared to control. There was also a decrease in minimum HR after ZD 7155 + L-NAME at 1 week. These data provide new evidence that, together, Ang II and NO regulate cardiovascular homeostasis as well as the arterial baroreflex of HR early in life which may help to explain the activation of these two systems early in life.
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Affiliation(s)
- Stephanie J Wehlage
- Alberta Children’s Hospital Research Institute for Child and Maternal Health, University of Calgary, Calgary, Alberta, Canada
| | - Francine G Smith
- Alberta Children’s Hospital Research Institute for Child and Maternal Health, University of Calgary, Calgary, Alberta, Canada
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Śleszyńska M, Wierzba TH, Malinowski K, Borovičková L, Małuch I, Sobolewski D, Lammek B, Slaninová J, Prahl A. Novel analogues of bradykinin conformationally restricted in the C-terminal part of the molecule. J Pept Sci 2011; 17:366-72. [DOI: 10.1002/psc.1351] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Revised: 10/30/2010] [Accepted: 12/12/2010] [Indexed: 11/09/2022]
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Xu P, Sriramula S, Lazartigues E. ACE2/ANG-(1-7)/Mas pathway in the brain: the axis of good. Am J Physiol Regul Integr Comp Physiol 2010; 300:R804-17. [PMID: 21178125 DOI: 10.1152/ajpregu.00222.2010] [Citation(s) in RCA: 202] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The last decade has seen the discovery of several new components of the renin-angiotensin system (RAS). Among them, angiotensin converting enzyme-2 (ACE2) and the Mas receptor have forced a reevaluation of the original cascade and led to the emergence of a new arm of the RAS: the ACE2/ANG-(1-7)/Mas axis. Accordingly, the new system is now seen as a balance between a provasoconstrictor, profibrotic, progrowth axis (ACE/ANG-II/AT(1) receptor) and a provasodilatory, antifibrotic, antigrowth arm (ACE2/ANG-(1-7)/Mas receptor). Already, this simplistic vision is evolving and new components are branching out upstream [ANG-(1-12) and (pro)renin receptor] and downstream (angiotensin-IV and other angiotensin peptides) of the classical cascade. In this review, we will summarize the role of the ACE2/ANG-(1-7)/Mas receptor, focusing on the central nervous system with respect to cardiovascular diseases such as hypertension, chronic heart failure, and stroke, as well as neurological diseases. In addition, we will discuss the new pharmacological (antagonists, agonists, activators) and genomic (knockout and transgenic animals) tools that are currently available. Finally, we will review the latest data regarding the various signaling pathways downstream of the Mas receptor.
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Affiliation(s)
- Ping Xu
- Department of Pharmacology and Experimental Therapeutics and Cardiovascular Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, USA
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18
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Abstract
Angiotensin-converting enzyme 2 (ACE2) is a new component of the renin-angiotensin system (RAS). Accumulating evidence shows that ACE2 provides protective effects in peripheral tissues and has great potential for the treatment of RAS-related diseases. The role of ACE2 in the central nervous system is not well established. However, in recent years, much more progress has been made on the studies of this carboxypeptidase in the central regulation of blood pressure and cardiovascular function in general. It has been shown that brain ACE2 interacts with the other components of the RAS (ACE, angiotensin II, and angiotensin II type 1 receptor), protects baroreflex and autonomic function, stimulates nitric oxide release, reduces oxidative stress, and prevents the development of or attenuates hypertension. These data support the critical role of ACE2 in the central regulation of cardiovascular function. This review summarizes recently published data on the central effects of ACE2 in the regulation of cardiovascular function.
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Affiliation(s)
- Huijing Xia
- School of Medicine, Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, 1901 Perdido Street, Room 5218, New Orleans, LA 70112 USA
| | - Eric Lazartigues
- School of Medicine, Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, 1901 Perdido Street, Room 5218, New Orleans, LA 70112 USA
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Zamo FS, Lacchini S, Mostarda C, Chiavegatto S, Silva ICM, Oliveira EM, Irigoyen MC. Hemodynamic, morphometric and autonomic patterns in hypertensive rats - Renin-Angiotensin system modulation. Clinics (Sao Paulo) 2010; 65:85-92. [PMID: 20126350 PMCID: PMC2815287 DOI: 10.1590/s1807-59322010000100013] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Accepted: 10/22/2009] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Spontaneously hypertensive rats develop left ventricular hypertrophy, increased blood pressure and blood pressure variability, which are important determinants of heart damage, like the activation of renin-angiotensin system. AIMS To investigate the effects of the time-course of hypertension over 1) hemodynamic and autonomic patterns (blood pressure; blood pressure variability; heart rate); 2) left ventricular hypertrophy; and 3) local and systemic Renin-angiotensin system of the spontaneously hypertensive rats. METHODS MALE SPONTANEOUSLY HYPERTENSIVE RATS WERE RANDOMIZED INTO TWO GROUPS: young (n=13) and adult (n=12). Hemodynamic signals (blood pressure, heart rate), blood pressure variability (BPV) and spectral analysis of the autonomic components of blood pressure were analyzed. LEFT ventricular hypertrophy was measured by the ratio of LV mass to body weight (mg/g), by myocyte diameter (mum) and by relative fibrosis area (RFA, %). ACE and ACE2 activities were measured by fluorometry (UF/min), and plasma renin activity (PRA) was assessed by a radioimmunoassay (ng/mL/h). Cardiac gene expressions of Agt, Ace and Ace2 were quantified by RT-PCR (AU). RESULTS The time-course of hypertension in spontaneously hypertensive rats increased BPV and reduced the alpha index in adult spontaneously hypertensive rats. Adult rats showed increases in left ventricular hypertrophy and in RFA. Compared to young spontaneously hypertensive rats, adult spontaneously hypertensive rats had lower cardiac ACE and ACE2 activities, and high levels of PRA. No change was observed in gene expression of Renin-angiotensin system components. CONCLUSIONS The observed autonomic dysfunction and modulation of Renin-angiotensin system activity are contributing factors to end-organ damage in hypertension and could be interacting. Our findings suggest that the management of hypertensive disease must start before blood pressure reaches the highest stable levels and the consequent established end-organ damage is reached.
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Affiliation(s)
- Fernanda S Zamo
- Nephrology Department, Federal University of São Paulo - São Paulo/SP, Brazil.
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Abstract
In the present study, we investigated the effects of basal and intra-arterial infusion of bradykinin on unstressed forearm vascular volume (a measure of venous tone) and blood flow in healthy volunteers (n=20) and in chronic heart failure patients treated with ACEIs [ACE (angiotensin-converting enzyme) inhibitors] (n=16) and ARBs (angiotensin receptor blockers) (n=14). We used radionuclide plethysmography to examine the effects of bradykinin and of the bradykinin antagonists B9340 [B1 (type 1)/B2 (type 2) receptor antagonist] and HOE140 (B2 antagonist). Bradykinin infusion increased unstressed forearm vascular volume in a similar dose-dependent manner in healthy volunteers and ARB-treated CHF patients (healthy volunteers maximum 12.3±2.1%, P<0.001 compared with baseline; ARB-treated CHF patients maximum 9.3±3.3%, P<0.05 compared with baseline; P=not significant for difference between groups), but the increase in unstressed volume in ACEI-treated CHF patients was higher (maximum 28.8±7.8%, P<0.001 compared with baseline; P<0.05 for the difference between groups). In contrast, while the increase in blood flow in healthy volunteers (maximum 362±9%, P<0.001) and in ACEI-treated CHF patients (maximum 376±12%, P<0.001) was similar (P=not significant for the difference between groups), the increase in ARB-treated CHF patients was less (maximum 335±7%, P<0.001; P<0.05 for the difference between groups). Infusion of each receptor antagonist alone similarly reduced basal unstressed volume and blood flow in ACEI-treated CHF patients, but not in healthy volunteers or ARB-treated CHF patients. In conclusion, bradykinin does not contribute to basal venous tone in health, but in ACEI-treated chronic heart failure it does. In ARB-treated heart failure, venous responses to bradykinin are preserved but arterial responses are reduced compared with healthy controls. Bradykinin-mediated vascular responses in both health and heart failure are mediated by the B2, rather than the B1, receptor.
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Xia H, Lazartigues E. Angiotensin-converting enzyme 2 in the brain: properties and future directions. J Neurochem 2008; 107:1482-94. [PMID: 19014390 PMCID: PMC2667944 DOI: 10.1111/j.1471-4159.2008.05723.x] [Citation(s) in RCA: 249] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Angiotensin (Ang)-converting enzyme (ACE) 2 cleaves Ang-II into the vasodilator peptide Ang-(1-7), thus acting as a pivotal element in balancing the local effects of these peptides. ACE2 has been identified in various tissues and is supposed to be a modulator of cardiovascular function. Decreases in ACE2 expression and activity have been reported in models of hypertension, heart failure, atherosclerosis, diabetic nephropathy and others. In addition, the expression level and/or activity are affected by other renin-angiotensin system components (e.g., ACE and AT1 receptors). Local inhibition or global deletion of brain ACE2 induces a reduction in baroreflex sensitivity. Moreover, ACE2-null mice have been shown to exhibit either blood pressure or cardiac dysfunction phenotypes. On the other hand, over-expression of ACE2 exerts protective effects in local tissues, including the brain. In this review, we will first summarize the major findings linking ACE2 to cardiovascular function in the periphery then focus on recent discoveries related to ACE2 in the CNS. Finally, we will unveil new tools designed to address the importance of central ACE2 in various diseases, and discuss the potential for this carboxypeptidase as a new target in the treatment of hypertension and other cardiovascular diseases.
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Affiliation(s)
- Huijing Xia
- Department of Pharmacology and Experimental Therapeutics and Cardiovascular Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
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Marangoni RA, Carmona AK, Passaglia RCAT, Nigro D, Fortes ZB, de Carvalho MHC. Role of the kallikrein-kinin system in Ang-(1-7)-induced vasodilation in mesenteric arterioles of Wistar rats studied in vivo-in situ. Peptides 2006; 27:1770-5. [PMID: 16595159 DOI: 10.1016/j.peptides.2006.02.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2005] [Revised: 02/01/2006] [Accepted: 02/03/2006] [Indexed: 11/17/2022]
Abstract
Angiotensin-(1-7) [Ang-(1-7)], exerts a variety of actions in the cardiovascular system, with an important effect being vasodilation. In this work, we investigated the relationship between the vasodilatory activity of Ang-(1-7) and the kallikrein-kinin system. Intravital microscopy was used to study the vasodilation caused by Ang-(1-7) in the mesenteric vascular bed of anesthetized Wistar rats. The topical application of Ang-(1-7) caused vasodilation of mesenteric arterioles that was reduced by A-779, JE 049 and peptidase inhibitors (aprotinin, SBTI, PKSI 527, E-64, PMSF). These results indicated that the vasodilation induced by Ang-(1-7) in the mesenteric arterioles of Wistar rats was heavily dependent on the activation of kallikrein and subsequent kinin formation.
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Affiliation(s)
- Rossana Anderson Marangoni
- Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo (USP), Av. Prof. Lineu Prestes 1524, Cidade Universitária, 05508-900 São Paulo, SP, Brazil
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Maia LG, Ramos MC, Fernandes L, de Carvalho MHC, Campagnole-Santos MJ, Souza dos Santos RA. Angiotensin-(1-7) antagonist A-779 attenuates the potentiation of bradykinin by captopril in rats. J Cardiovasc Pharmacol 2004; 43:685-91. [PMID: 15071356 DOI: 10.1097/00005344-200405000-00011] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
We evaluated the possibility that endogenous angiotensin-(1-7) [Ang-(1-7)] could participate in the potentiation of bradykinin (BK) by the angiotensin-converting enzyme inhibitor (ACEI) captopril in conscious Wistar rats. Catheters were introduced into descending aorta (through the left carotid artery) for BK injection, femoral artery for arterial pressure measurement, and both femoral veins for BK injection and vehicle or Ang-(1-7) antagonist, A-779 infusion. Infusion of vehicle or A-779 started 40 to 45 minutes after captopril administration. Sequential BK dose-response curves were made before, 10 minutes after captopril, and within 10 minutes of infusion of vehicle or A-779. To evaluate angiotensin I conversion, dose-response curves for angiotensin I and angiotensin II were made following the same protocol used for BK. Captopril treatment markedly increased the BK hypotensive effect and significantly decreased angiotensin I conversion. Infusion of A-779 did not modify the angiotensin II pressor effect or the effect of captopril on angiotensin I conversion. However, A-779 significantly reduced the potentiating effect of captopril on the hypotensive effect of BK administered intravenously or intra-arterially. These results suggest that endogenous Ang-(1-7) and/ or an Ang-(1-7)-related peptide plays an important role in the BK potentiation by ACEI through a mechanism not dependent upon inhibition of ACE hydrolytic activity.
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Affiliation(s)
- Luciana Gonçalves Maia
- Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
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Qadri F, Schwartz EC, Häuser W, Jöhren O, Müller-Esterl W, Dominiak P. Kinin B2 receptor localization and expression in the hypothalamo-pituitary-adrenal axis of spontaneously hypertensive rats. Int Immunopharmacol 2003; 3:285-92. [PMID: 12639805 DOI: 10.1016/s1567-5769(02)00269-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
OBJECTIVE An enhanced hypothalamo-pituitary-adrenocortical (HPA) activity has been demonstrated during onset of high blood pressure in spontaneously hypertensive rats (SHR). Furthermore, compared to normotensive Wistar-Kyoto (WKY) rats, SHR show hypersensitivity to bradykinin (BK)-induced pressor responses which may be caused by an upregulation of B(2) receptor expression in the brain. METHODS We performed an immunohistochemical localization and measured gene expression of B(2) receptors in the hypothalamus, pituitary and adrenal glands of SHR at three ages corresponding to the development of hypertension, i.e. prehypertensive phase, onset of hypertension and established hypertension. Using reverse transcriptase polymerase chain reaction (RT-PCR) and Western blot technique, B(2) receptor mRNA and protein levels, respectively, were measured. RESULTS A specific immunostaining for B(2) receptors was observed in the hypothalamic nuclei paraventricularis (PVN) and supraopticus (SON). In the pituitary and adrenal glands, a strong immunostaining was observed in neurohypophysis (NH) and adrenal medulla, respectively. At all ages tested, B(2) receptor mRNA and protein levels were higher in the hypothalamus and adrenal glands of SHR compared to age-matched WKY rats. Among SHR, the mRNA level was increased in neurohypophysis with age, and no difference was found in the adenohypophysis (AH) between SHR and WKY rats. CONCLUSION The data demonstrate a specific localization and an upregulation of B(2) receptor expression in the hypothalamus and adrenal glands of SHR, providing an anatomical and molecular basis for a possible contributory role to bradykinin-induced hypersensitivity of cardiovascular responses. The increased B(2) receptor expression in the hypothalamus and adrenal glands may also play a role in the abnormalities of the HPA axis in SHR during the development of hypertension.
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Affiliation(s)
- Fatimunnisa Qadri
- Institute of Experimental and Clinical Pharmacology and Toxicology, University Clinic of Lübeck, Ratzeburger Allee 160, D-23538 Lübeck, Germany.
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Cesari M, Rossi GP, Pessina AC. Biological properties of the angiotensin peptides other than angiotensin II: implications for hypertension and cardiovascular diseases. J Hypertens 2002; 20:793-9. [PMID: 12011628 DOI: 10.1097/00004872-200205000-00002] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Several peptides of the RAS other than angiotensin (1-8) have been identified. They are generally referred as 'angiotensin fragments': Ang (2-8), Ang (3-8) and Ang (1-7) and have been detected in human tissues. There is evidence that they may play a functional role in humans by acting in concert with angiotensin (1-8) and aldosterone. Available knowledge on the pathways leading to synthesis and degradation of angiotensin fragments, as well as on their interactions with receptors and on their possible role in cardiovascular homeostasis and disease are reviewed.
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Affiliation(s)
- Maurizio Cesari
- Department of Clinical and Experimental Medicine, University of Padua, Italy.
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Souza Dos Santos RA, Passaglio KT, Pesquero JB, Bader M, Simões E Silva AC. Interactions between angiotensin-(1-7), kinins, and angiotensin II in kidney and blood vessels. Hypertension 2001; 38:660-4. [PMID: 11566951 DOI: 10.1161/01.hyp.38.3.660] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The heptapeptide angiotensin (Ang)-(1-7) is currently considered one of the biologically active end products of the renin-angiotensin system. The formation of Ang-(1-7) by pathways independent of Ang II generation, the selectivity of its actions, and its peculiar property of exhibiting effects that are partially opposite of those of the parent compound, Ang II, confer a unique biochemical and functional profile to this peptide. In this article, we will review novel aspects of the biological actions of Ang-(1-7), dealing with its interaction with Ang II and kinins, especially in the kidney and blood vessels.
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Affiliation(s)
- R A Souza Dos Santos
- Laboratório de Hipertensão, Instituto de Ciências Biológicas, Departamento de Pediatria, Fac. Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
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Heringer-Walther S, Walther T, Khosla MC, Santos RA, Campagnole-Santos MJ. Baroreflex improvement in shr after ace inhibition involves angiotensin-(1-7). Hypertension 2001; 37:1309-14. [PMID: 11358946 DOI: 10.1161/01.hyp.37.5.1309] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
ACE inhibitors are extensively used in the treatment of hypertension mainly because of their efficiency in reducing blood pressure levels and decreasing vascular and cardiac hypertrophy. In addition, ACE inhibitors improve baroreceptor reflex control. Chronic inhibition of ACE produces (in addition to decreased angiotensin II levels) a severe increase in angiotensin-(1-7) [Ang-(1-7)] levels in several species. We have previously shown that Ang-(1-7) produces a facilitation of the baroreflex control of heart rate. In this study, we evaluated the participation of endogenous Ang-(1-7) in the improvement of baroreflex sensitivity in spontaneously hypertensive rats after central infusion of ramiprilat, an ACE inhibitor. Reflex changes in heart rate were elicited, in conscious rats, by bolus injections of phenylephrine (baroreflex bradycardia) before and after intracerebroventricular infusion of (1) saline (8 microL/h), 4 hours (n=5); (2) ramiprilat (14 microg/h), 4 hours (n=6); (3) ramiprilat for 2 hours, followed by ramiprilat combined with A-779 (4 microg/h), a selective Ang-(1-7) antagonist, for an additional 2 hours (n=6); and (4) A-779 for 2 hours, followed by A-779 combined with ramiprilat for an additional 2 hours (n=5). Intracerebroventricular infusion of ramiprilat produced an important increase ( approximately 40%) in baroreflex sensitivity (evaluated as the ratio between changes in heart rate and changes in mean arterial pressure) that was completely reversed by A-779. Furthermore, intracerebroventricular infusion of A-779 prevented the improvement of the baroreflex sensitivity produced by ramiprilat. Intracerebroventricular infusion of saline or A-779 alone did not significantly alter the baroreflex sensitivity. These results suggest that endogenous Ang-(1-7) is involved in the improvement of baroreflex sensitivity observed in spontaneously hypertensive rats during central ACE inhibition.
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Affiliation(s)
- S Heringer-Walther
- Department of Physiology and Biophysics, Biological Sciences Institute, Federal University of Minas Gerais, Belo Horizonte, Brazil
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Abstract
The renin-angiotensin system is a major physiological regulator of arterial pressure and hydro-electrolyte balance. Evidence has now been accumulated that in addition to angiotensin (Ang) II other Ang peptides [Ang III, Ang IV and Ang-(1-7)], formed in the limited proteolysis processing of angiotensinogen, are importantly involved in mediating several actions of the RAS. In this article we will review our knowledge of the biological actions of Ang-(1-7) with focus on the puzzling aspects of the mediation of its effects and the interaction Ang-(1-7)-kinins. In addition, we will attempt to summarize the evidence that Ang-(1-7) takes an important part of the mechanisms aimed to counteract the vasoconstrictor and proliferative effects of Ang II.
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Affiliation(s)
- R A Santos
- Departamento de Fisiologia e Biofísica, Av. Antonio Carlos, 6627 - Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, 31270-901, Belo Horizonte, MG Brazil.
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Slavachevsky I, Rachmani R, Levi Z, Brosh D, Lidar M, Ravid M. Effect of enalapril and nifedipine on orthostatic hypotension in older hypertensive patients. J Am Geriatr Soc 2000; 48:807-10. [PMID: 10894321 DOI: 10.1111/j.1532-5415.2000.tb04757.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To compare the effect of enalapril with long-acting nifedipine on orthostatic hypotension in older patients. DESIGN A prospective, double blinded, cross-over study. SETTING The outpatient clinic of a university hospital. PARTICIPANTS Thirty-nine patients aged 65 years or older with systolic blood pressure (SBP) of 140-190 mm Hg and diastolic blood pressure (DBP) of 90-110 mm Hg. INTERVENTION Enalapril 5-20 mg od or nifedipine 30-90 mg od for 8 weeks, followed by 4 weeks washout and cross-over for a second 8-week period. MEASUREMENTS Supine and standing 0-, 1-, and 5-minutes blood pressure was recorded before and at the end of each treatment period. RESULTS At baseline, SBP was 158.8 +/- 8.7 mm Hg, and DBP was 97.1 +/- 5.9 mm Hg. There was a decline in SBP of 6.1 +/- 2.7 mm Hg and 8.4 +/- 4.1 mm Hg after 1 and 5 minutes of standing, respectively. Both agents caused a significant decline in supine blood pressure. Enalapril: supine SBP 158.8 +/- 8.7 to 143 +/- 7.3 mm Hg; supine DBP 97.1 +/- 5.9 to 85.1 +/- 5.1 mm Hg (P = .0001). The drop in SBP after standing for 5 minutes was only 2.4 +/- 1.6 mm Hg with no change in diastolic values. A > or = 10 mm Hg drop in SBP was observed in only three patients, and no patient experienced a decline of 20 mm Hg or more. Nifedipine: supine SBP: 160.3 +/- 9 to 145.3 +/- 8.1 mm Hg; supine DBP: 96.3 +/- 5.7 to 86.3 +/- 5.8 (P = .0001). Nifedipine induced an orthostatic decline in SBP values; there was an 8.7 +/- 4.8 mm Hg difference between supine and 5 minutes standing values (P = .0005) without change in diastolic values. An orthostatic decline in SBP of > or = 10 mm Hg occurred in 13 patients, and there was a drop of > or = 20 mm Hg in six patients. The cross-over of enalapril and nifedipine reproduced the hypotensive effect and reversed the postural effect. (P = .0002 nifedipine vs enalapril) CONCLUSIONS Enalapril and nifedipine were equipotent in reducing supine blood pressure levels. Enalapril also reduced the number of orthostatic episodes significantly, whereas nifedipine aggravated this phenomenon.
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Affiliation(s)
- I Slavachevsky
- Department of Medicine, Meir Hospital, Kfar-Sava, Israel
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Gaudet E, Godwin SJ, Head GA. Effects of central infusion of ANG II and losartan on the cardiac baroreflex in rabbits. Am J Physiol Heart Circ Physiol 2000; 278:H558-66. [PMID: 10666088 DOI: 10.1152/ajpheart.2000.278.2.h558] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effect of chronic activation or inhibition of central ANG II receptors on cardiac baroreflex function in conscious normotensive rabbits was examined. Animals received a fourth ventricular (4V) infusion of ANG II (30 and 100 ng/h), losartan (3 and 30 microg/h), or Ringer solution (2 microl/h) for 2 wk. After 1 and 2 wk, ANG II (100 ng/h) decreased cardiac baroreflex gain by 20 and 37%, respectively (P = 0.015), whereas losartan (30 microg/h) increased baroreflex gain by 24 and 58%, respectively (P = 0.02). Within 1 wk of the end of the infusions, cardiac baroreflex gain had returned to control. Ringer solution or the lower doses of ANG II or losartan did not modify the cardiac baroreflex function. Blood pressure and heart rate were not altered by any treatment, nor was their variability affected. These data demonstrate a novel long-term modulation of cardiac baroreflexes by endogenous ANG II that is independent of blood pressure level.
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Affiliation(s)
- E Gaudet
- Baker Medical Research Institute, Melbourne, Victoria 8008, Australia.
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