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Owens CD, Bonin Pinto C, Detwiler S, Olay L, Pinaffi-Langley ACDC, Mukli P, Peterfi A, Szarvas Z, James JA, Galvan V, Tarantini S, Csiszar A, Ungvari Z, Kirkpatrick AC, Prodan CI, Yabluchanskiy A. Neurovascular coupling impairment as a mechanism for cognitive deficits in COVID-19. Brain Commun 2024; 6:fcae080. [PMID: 38495306 PMCID: PMC10943572 DOI: 10.1093/braincomms/fcae080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 02/08/2024] [Accepted: 03/05/2024] [Indexed: 03/19/2024] Open
Abstract
Components that comprise our brain parenchymal and cerebrovascular structures provide a homeostatic environment for proper neuronal function to ensure normal cognition. Cerebral insults (e.g. ischaemia, microbleeds and infection) alter cellular structures and physiologic processes within the neurovascular unit and contribute to cognitive dysfunction. COVID-19 has posed significant complications during acute and convalescent stages in multiple organ systems, including the brain. Cognitive impairment is a prevalent complication in COVID-19 patients, irrespective of severity of acute SARS-CoV-2 infection. Moreover, overwhelming evidence from in vitro, preclinical and clinical studies has reported SARS-CoV-2-induced pathologies in components of the neurovascular unit that are associated with cognitive impairment. Neurovascular unit disruption alters the neurovascular coupling response, a critical mechanism that regulates cerebromicrovascular blood flow to meet the energetic demands of locally active neurons. Normal cognitive processing is achieved through the neurovascular coupling response and involves the coordinated action of brain parenchymal cells (i.e. neurons and glia) and cerebrovascular cell types (i.e. endothelia, smooth muscle cells and pericytes). However, current work on COVID-19-induced cognitive impairment has yet to investigate disruption of neurovascular coupling as a causal factor. Hence, in this review, we aim to describe SARS-CoV-2's effects on the neurovascular unit and how they can impact neurovascular coupling and contribute to cognitive decline in acute and convalescent stages of the disease. Additionally, we explore potential therapeutic interventions to mitigate COVID-19-induced cognitive impairment. Given the great impact of cognitive impairment associated with COVID-19 on both individuals and public health, the necessity for a coordinated effort from fundamental scientific research to clinical application becomes imperative. This integrated endeavour is crucial for mitigating the cognitive deficits induced by COVID-19 and its subsequent burden in this especially vulnerable population.
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Affiliation(s)
- Cameron D Owens
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Camila Bonin Pinto
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Sam Detwiler
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
| | - Lauren Olay
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
| | - Ana Clara da C Pinaffi-Langley
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
| | - Peter Mukli
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Departments of Public Health, Translational Medicine and Physiology, Semmelweis University, Budapest, 1089, Hungary
| | - Anna Peterfi
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Departments of Public Health, Translational Medicine and Physiology, Semmelweis University, Budapest, 1089, Hungary
| | - Zsofia Szarvas
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Departments of Public Health, Translational Medicine and Physiology, Semmelweis University, Budapest, 1089, Hungary
| | - Judith A James
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Arthritis & Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
- Department of Internal Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Veronica Galvan
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- Veterans Affairs Medical Center, Oklahoma City, OK 73104, USA
| | - Stefano Tarantini
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Departments of Public Health, Translational Medicine and Physiology, Semmelweis University, Budapest, 1089, Hungary
- The Peggy and Charles Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Anna Csiszar
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Departments of Public Health, Translational Medicine and Physiology, Semmelweis University, Budapest, 1089, Hungary
| | - Zoltan Ungvari
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Departments of Public Health, Translational Medicine and Physiology, Semmelweis University, Budapest, 1089, Hungary
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Angelia C Kirkpatrick
- Veterans Affairs Medical Center, Oklahoma City, OK 73104, USA
- Cardiovascular Section, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
| | - Calin I Prodan
- Veterans Affairs Medical Center, Oklahoma City, OK 73104, USA
- Department of Neurology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Andriy Yabluchanskiy
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Departments of Public Health, Translational Medicine and Physiology, Semmelweis University, Budapest, 1089, Hungary
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
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Colin M, Delaitre C, Foulquier S, Dupuis F. The AT 1/AT 2 Receptor Equilibrium Is a Cornerstone of the Regulation of the Renin Angiotensin System beyond the Cardiovascular System. Molecules 2023; 28:5481. [PMID: 37513355 PMCID: PMC10383525 DOI: 10.3390/molecules28145481] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 07/11/2023] [Accepted: 07/14/2023] [Indexed: 07/30/2023] Open
Abstract
The AT1 receptor has mainly been associated with the pathological effects of the renin-angiotensin system (RAS) (e.g., hypertension, heart and kidney diseases), and constitutes a major therapeutic target. In contrast, the AT2 receptor is presented as the protective arm of this RAS, and its targeting via specific agonists is mainly used to counteract the effects of the AT1 receptor. The discovery of a local RAS has highlighted the importance of the balance between AT1/AT2 receptors at the tissue level. Disruption of this balance is suggested to be detrimental. The fine tuning of this balance is not limited to the regulation of the level of expression of these two receptors. Other mechanisms still largely unexplored, such as S-nitrosation of the AT1 receptor, homo- and heterodimerization, and the use of AT1 receptor-biased agonists, may significantly contribute to and/or interfere with the settings of this AT1/AT2 equilibrium. This review will detail, through several examples (the brain, wound healing, and the cellular cycle), the importance of the functional balance between AT1 and AT2 receptors, and how new molecular pharmacological approaches may act on its regulation to open up new therapeutic perspectives.
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Affiliation(s)
- Mélissa Colin
- CITHEFOR, Université de Lorraine, F-54000 Nancy, France
- Department of Pharmacology and Toxicology, MHeNS-School for Mental Health and Neuroscience, Maastricht University, 6200 MD Maastricht, The Netherlands
| | | | - Sébastien Foulquier
- Department of Pharmacology and Toxicology, MHeNS-School for Mental Health and Neuroscience, Maastricht University, 6200 MD Maastricht, The Netherlands
- CARIM-School for Cardiovascular Diseases, Maastricht University, 6200 MD Maastricht, The Netherlands
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Tacke C, Bischoff AM, Harb A, Vafadari B, Hülsmann S. Angiotensin II increases respiratory rhythmic activity in the preBötzinger complex without inducing astroglial calcium signaling. Front Cell Neurosci 2023; 17:1111263. [PMID: 36816850 PMCID: PMC9932970 DOI: 10.3389/fncel.2023.1111263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 01/17/2023] [Indexed: 02/05/2023] Open
Abstract
Angiotensin II (Ang II) is the primary modulator of the renin-angiotensin system and has been widely studied for its effect on the cardiovascular system. While a few studies have also indicated an involvement of Ang II in the regulation of breathing, very little is known in this regard and its effect on brainstem respiratory regions such as the preBötzinger complex (preBötC), the kernel for inspiratory rhythm generation, has not been investigated yet. This study reports that Ang II temporarily increases phrenic nerve activity in the working heart-brainstem preparation, indicating higher central respiratory drive. Previous studies have shown that the carotid body is involved in mediating this effect and we revealed that the preBötC also plays a part, using acute slices of the brainstem. It appears that Ang II is increasing the respiratory drive in an AT1R-dependent manner by optimizing the interaction of inhibitory and excitatory neurons of the preBötC. Thus, Ang II-mediated effects on the preBötC are potentially involved in dysregulating breathing in patients with acute lung injury.
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Saha PS, Knecht TM, Arrick DM, Watt MJ, Scholl JL, Mayhan WG. Prenatal exposure to alcohol impairs responses of cerebral arterioles to activation of potassium channels: Role of oxidative stress. ALCOHOL, CLINICAL & EXPERIMENTAL RESEARCH 2023; 47:87-94. [PMID: 36446735 PMCID: PMC9974881 DOI: 10.1111/acer.14980] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 10/24/2022] [Accepted: 11/17/2022] [Indexed: 11/23/2022]
Abstract
BACKGROUND Potassium channels play an important role in the basal tone and dilation of cerebral resistance arterioles in response to many stimuli. However, the effect of prenatal alcohol exposure (PAE) on specific potassium channel function remains unknown. The first goal of this study was to determine the influence of PAE on the reactivity of cerebral arterioles to activation of ATP-sensitive potassium (KATP ) and BK channels. Our second goal was to determine whether oxidative stress contributed to potassium channel dysfunction of cerebral arterioles following PAE. METHODS We fed Sprague-Dawley dams a liquid diet with or without alcohol (3% EtOH) for the duration of their pregnancy (21 to 23 days). We examined in vivo responses of cerebral arterioles in control and PAE male and female offspring (14 to 16 weeks after birth) to activators of potassium channels (Iloprost [BK channels] and pinacidil [KATP channels]), before and following inhibition of oxidative stress with apocynin. RESULTS We found that PAE impaired dilation of cerebral arterioles in response to activation of potassium channels with iloprost and pinacidil, and this impairment was similar in male and female rats. In addition, treatment with apocynin reversed the impaired vasodilation to iloprost and pinacidil in PAE rats to levels observed in control rats. This effect of apocynin also was similar in male and female rats. CONCLUSIONS PAE induces dysfunction in the ability of specific potassium channels to dilate cerebral arterioles which appears to be mediated by an increase in oxidative stress. We suggest that these alterations in potassium channel function may contribute to the pathogenesis of cerebral vascular abnormalities and/or behavioral/cognitive deficits observed in fetal alcohol spectrum disorders.
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Affiliation(s)
- Partha S. Saha
- Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD 57069
| | - Tiffany M. Knecht
- Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD 57069
| | - Denise M. Arrick
- Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD 57069
| | - Michael J. Watt
- Department of Anatomy, University of Otago, Dunedin, New Zealand
| | - Jamie L. Scholl
- Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD 57069
| | - William G. Mayhan
- Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD 57069
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Delaitre C, Boisbrun M, Lecat S, Dupuis F. Targeting the Angiotensin II Type 1 Receptor in Cerebrovascular Diseases: Biased Signaling Raises New Hopes. Int J Mol Sci 2021; 22:ijms22136738. [PMID: 34201646 PMCID: PMC8269339 DOI: 10.3390/ijms22136738] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 06/17/2021] [Accepted: 06/20/2021] [Indexed: 12/20/2022] Open
Abstract
The physiological and pathophysiological relevance of the angiotensin II type 1 (AT1) G protein-coupled receptor no longer needs to be proven in the cardiovascular system. The renin–angiotensin system and the AT1 receptor are the targets of several classes of therapeutics (such as angiotensin converting enzyme inhibitors or angiotensin receptor blockers, ARBs) used as first-line treatments in cardiovascular diseases. The importance of AT1 in the regulation of the cerebrovascular system is also acknowledged. However, despite numerous beneficial effects in preclinical experiments, ARBs do not induce satisfactory curative results in clinical stroke studies. A better understanding of AT1 signaling and the development of biased AT1 agonists, able to selectively activate the β-arrestin transduction pathway rather than the Gq pathway, have led to new therapeutic strategies to target detrimental effects of AT1 activation. In this paper, we review the involvement of AT1 in cerebrovascular diseases as well as recent advances in the understanding of its molecular dynamics and biased or non-biased signaling. We also describe why these alternative signaling pathways induced by β-arrestin biased AT1 agonists could be considered as new therapeutic avenues for cerebrovascular diseases.
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Affiliation(s)
- Céline Delaitre
- CITHEFOR, Université de Lorraine, F-54000 Nancy, France;
- Biotechnologie et Signalisation Cellulaire, UMR7242 CNRS/Université de Strasbourg, 300 Boulevard Sébastien Brant, CS 10413, CEDEX, 67412 Illkirch-Graffenstaden, France;
| | | | - Sandra Lecat
- Biotechnologie et Signalisation Cellulaire, UMR7242 CNRS/Université de Strasbourg, 300 Boulevard Sébastien Brant, CS 10413, CEDEX, 67412 Illkirch-Graffenstaden, France;
| | - François Dupuis
- CITHEFOR, Université de Lorraine, F-54000 Nancy, France;
- Correspondence: ; Tel.: +33-372747272
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Li Z, Lindner DP, Bishop NM, Cipolla MJ. ACE (Angiotensin-Converting Enzyme) Inhibition Reverses Vasoconstriction and Impaired Dilation of Pial Collaterals in Chronic Hypertension. Hypertension 2020; 76:226-235. [PMID: 32418498 DOI: 10.1161/hypertensionaha.119.14315] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Leptomeningeal anastomoses (LMAs) are pial collaterals that perfuse the penumbra and important for stroke outcome. We previously showed LMAs from SHRs (spontaneously hypertensive rats) were vasoconstricted compared with normotensive Wistar rats. Here, we investigated mechanisms by which hypertension causes LMA vasoconstriction. SHRs were treated with the ACE (angiotensin-converting enzyme) inhibitor captopril, an Ang II (angiotensin II)-independent antihypertensive agent hydralazine, or vehicle for 5 weeks in drinking water (n=8/group). A group of Wistar rats (n=8) had regular drinking water served as controls. Blood pressure was measured twice weekly by tail-cuff. LMAs were isolated and studied under pressurized conditions. Vasoreactivity of LMAs, including myogenic responses, reactivity to Rho-kinase inhibitor Y-27632, and nitric oxide were measured. Both captopril and hydralazine lowered blood pressure in SHRs similar to Wistar. However, only captopril normalized LMA increased tone compared with untreated SHRs (15±2% versus 50±3%; P<0.01) that was similar to Wistar (16±2%) but not hydralazine (38±6%; P>0.05). Vasodilatory response of LMAs to Y-27632 was impaired in SHRs compared with Wistar (28±3% versus 81±4%; P<0.01) that was restored by captopril (84±5%; P<0.01) and partially hydralazine (59±4%). LMAs from all groups constricted similarly to NOS (NO synthase) inhibition; however, the vasodilatory response of LMAs to the nitric oxide donor sodium nitroprusside was impaired in SHRs compared with Wistar rats (29±4% versus 80±2%; P<0.01) that was restored by captopril (84±4%; P<0.01), not hydralazine (38±8%; P>0.05). These results suggest that ACE inhibition during chronic hypertension reversed vascular dysfunction and hyperconstriction of LMAs that could improve stroke outcome by increasing collateral perfusion.
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Affiliation(s)
- Zhaojin Li
- From the Department of Neurological Sciences (Z.L., D.P.L., M.J.C.), University of Vermont Robert Larner College of Medicine, Burlington
| | - Devon P Lindner
- From the Department of Neurological Sciences (Z.L., D.P.L., M.J.C.), University of Vermont Robert Larner College of Medicine, Burlington
| | - Nicole M Bishop
- Department of Pathology (N.M.B.), University of Vermont Robert Larner College of Medicine, Burlington
| | - Marilyn J Cipolla
- From the Department of Neurological Sciences (Z.L., D.P.L., M.J.C.), University of Vermont Robert Larner College of Medicine, Burlington.,Department of Obstetrics, Gynecology, and Reproductive Sciences (M.J.C.), University of Vermont Robert Larner College of Medicine, Burlington.,Department of Pharmacology (M.J.C.), University of Vermont Robert Larner College of Medicine, Burlington
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Mishra JS, te Riele GM, Qi QR, Lechuga TJ, Gopalakrishnan K, Chen DB, Kumar S. Estrogen Receptor-β Mediates Estradiol-Induced Pregnancy-Specific Uterine Artery Endothelial Cell Angiotensin Type-2 Receptor Expression. Hypertension 2019; 74:967-974. [PMID: 31378106 PMCID: PMC6739159 DOI: 10.1161/hypertensionaha.119.13429] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 07/01/2019] [Indexed: 01/05/2023]
Abstract
The pregnancy-augmented uterine vasodilation is linked to increased AT2R (angiotensin type-2 receptor) that mediates the vasodilatory effects of angiotensin II. However, the mechanisms controlling AT2R expression during pregnancy remain unclear. Estrogens are known to play a role in vascular adaptations during pregnancy. We hypothesized that estrogen stimulates uterine artery AT2R expression via ER (estrogen receptor)-β-dependent transcription in a pregnancy-specific endothelium-dependent manner. Plasma estradiol levels increased and peaked in late pregnancy and returned to prepregnant levels post-partum, correlating with uterine artery AT2R and ERβ upregulation. Estradiol stimulated AT2R mRNA expression in endothelium-intact but not endothelium-denuded late pregnant and nonpregnant rat uterine artery ex vivo. Consistently, estradiol stimulated AT2R mRNA expression in late pregnant but not nonpregnant primary human uterine artery endothelial cells in vitro, which was abolished by ER antagonist ICI 182,780. Higher ERα protein bound to ER-responsive elements in AT2R promoter in the nonpregnant arteries whereas higher ERβ bound in the pregnant state. ERα protein levels were similar but higher ERβ protein levels were expressed in pregnant versus nonpregnant human uterine artery endothelial cells. Estradiol stimulation recruited ERα to the AT2R promoter in the nonpregnant state and ERβ to the AT2R promoter in pregnancy; however, only ERβ recruitment mediated transactivation of the AT2R reporter gene in pregnant human uterine artery endothelial cells. Estradiol-induced AT2R expression was abolished by the specific ERβ (not ERα) antagonist 4-[2-Phenyl-5,7-bis(trifluoromethyl)pyrazolo[1,5-a]pyrimidin-3-yl]phenol (PHTPP) and mimicked by the specific ERβ (not ERα) agonist 2,3-bis(4-Hydroxyphenyl)-propionitrile (DPN) in pregnant human uterine artery endothelial cells in vitro. This study demonstrates a novel role of pregnancy-augmented ERβ in AT2R upregulation in the uterine artery and provides new insights into the mechanisms underlying uterine vascular adaptation to pregnancy.
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Affiliation(s)
- Jay S. Mishra
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Gigi M. te Riele
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Qian-Rong Qi
- Department of Obstetrics & Gynecology, University of California-Irvine, Irvine, CA 92697, USA
| | - Thomas J. Lechuga
- Department of Obstetrics & Gynecology, University of California-Irvine, Irvine, CA 92697, USA
| | - Kathirvel Gopalakrishnan
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Dong-bao Chen
- Department of Obstetrics & Gynecology, University of California-Irvine, Irvine, CA 92697, USA
| | - Sathish Kumar
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53706, USA
- Department of Obstetrics and Gynecology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53706, USA
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Hirunpattarasilp C, Attwell D, Freitas F. The role of pericytes in brain disorders: from the periphery to the brain. J Neurochem 2019; 150:648-665. [PMID: 31106417 DOI: 10.1111/jnc.14725] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 03/15/2019] [Accepted: 05/15/2019] [Indexed: 12/13/2022]
Abstract
It is becoming increasingly apparent that disorders of the brain microvasculature contribute to many neurological disorders. In recent years it has become clear that a major player in these events is the capillary pericyte which, in the brain, is now known to control the blood-brain barrier, regulate blood flow, influence immune cell entry and be crucial for angiogenesis. In this review we consider the under-explored possibility that peripheral diseases which affect the microvasculature, such as hypertension, kidney disease and diabetes, produce central nervous system (CNS) dysfunction by mechanisms affecting capillary pericytes within the CNS. We highlight how cellular messengers produced peripherally can act via signalling pathways within CNS pericytes to reshape blood vessels, restrict blood flow or compromise blood-brain barrier function, thus causing neuronal dysfunction. Increased understanding of how renin-angiotensin, Rho-kinase and PDGFRβ signalling affect CNS pericytes may suggest novel therapeutic approaches to reducing the CNS effects of peripheral disorders.
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Affiliation(s)
- Chanawee Hirunpattarasilp
- Department of Neuroscience, Andrew Huxley Building, University College London, Physiology & Pharmacology, Gower Street, London, UK
| | - David Attwell
- Department of Neuroscience, Andrew Huxley Building, University College London, Physiology & Pharmacology, Gower Street, London, UK
| | - Felipe Freitas
- Department of Neuroscience, Andrew Huxley Building, University College London, Physiology & Pharmacology, Gower Street, London, UK
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Bouressam ML, Lecat S, Raoul A, Gaucher C, Perrin-Sarrado C, Lartaud I, Dupuis F. S-nitrosoglutathione inhibits cerebrovascular angiotensin II-dependent and -independent AT 1 receptor responses: A possible role of S-nitrosation. Br J Pharmacol 2019; 176:2049-2062. [PMID: 30822355 DOI: 10.1111/bph.14644] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 01/21/2019] [Accepted: 02/13/2019] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE Angiotensin II (AngII) and NO regulate the cerebral circulation. AngII AT1 receptors exert ligand-dependent and ligand-independent (myogenic tone [MT]) vasoconstriction of cerebral vessels. NO induces post-translational modifications of proteins such as S-nitrosation (redox modification of cysteine residues). In cultured cells, S-nitrosation decreases AngII's affinity for the AT1 receptor. The present work evaluated the functional consequences of S-nitrosation on both AngII-dependent and AngII-independent cerebrovascular responses. EXPERIMENTAL APPROACH S-Nitrosation was induced in rat isolated middle cerebral arteries by pretreatment with the NO donors, S-nitrosoglutathione (GSNO) or sodium nitroprusside (SNP). Agonist-dependent activation of AT1 receptors was evaluated by obtaining concentration-response curves to AngII. Ligand-independent activation of AT1 receptors was evaluated by calculating MT (active vs. passive diameter) at pressures ranging from 20 to 200 mmHg in the presence or not of a selective AT1 receptor inverse agonist. KEY RESULTS GSNO or SNP completely abolished the AngII-dependent AT1 receptor-mediated vasoconstriction of cerebral arteries. GSNO had no impact on responses to other vasoconstrictors sharing (phenylephrine, U46619) or not (5-HT) the same signalling pathway. MT was reduced by GSNO, and the addition of losartan did not further decrease MT, suggesting that GSNO blocks AT1 receptor-dependent MT. Ascorbate (which reduces S-nitrosated compounds) restored the response to AngII but not the soluble GC inhibitor ODQ, suggesting that these effects are mediated by S-nitrosation rather than by S-nitrosylation. CONCLUSIONS AND IMPLICATIONS In rat middle cerebral arteries, GSNO pretreatment specifically affects the AT1 receptor and reduces both AngII-dependent and AngII-independent activation, most likely through AT1 receptor S-nitrosation.
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Affiliation(s)
| | - Sandra Lecat
- BSC UMR7242 "GPCRs, pain and inflammation" team, CNRS, Université de Strasbourg Labex Medalis, Illkirch, France
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Allen LA, Schmidt JR, Thompson CT, Carlson BE, Beard DA, Lombard JH. High salt diet impairs cerebral blood flow regulation via salt-induced angiotensin II suppression. Microcirculation 2019; 26:e12518. [PMID: 30481399 DOI: 10.1111/micc.12518] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 10/03/2018] [Accepted: 11/22/2018] [Indexed: 01/11/2023]
Abstract
OBJECTIVES This study sought to determine whether salt-induced ANG II suppression contributes to impaired CBF autoregulation. METHODS Cerebral autoregulation was evaluated with LDF during graded reductions of blood pressure. Autoregulatory responses in rats fed HS (4% NaCl) diet vs LS (0.4% NaCl) diet were analyzed using linear regression analysis, model-free analysis, and a mechanistic theoretical model of blood flow through cerebral arterioles. RESULTS Autoregulation was intact in LS-fed animals as MAP was reduced via graded hemorrhage to approximately 50 mm Hg. Short-term (3 days) and chronic (4 weeks) HS diet impaired CBF autoregulation, as evidenced by progressive reductions of laser Doppler flux with arterial pressure reduction. Chronic low dose ANG II infusion (5 mg/kg/min, i.v.) restored CBF autoregulation between the pre-hemorrhage MAP and 50 mm Hg in rats fed short-term HS diet. Mechanistic-based model analysis showed a reduced myogenic response and reduced baseline VSM tone with short-term HS diet, which was restored by ANG II infusion. CONCLUSIONS Short-term and chronic HS diet lead to impaired autoregulation in the cerebral circulation, with salt-induced ANG II suppression as a major factor in the initiation of impaired CBF regulation.
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Affiliation(s)
- Linda A Allen
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - James R Schmidt
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Christopher T Thompson
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin.,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | - Brian E Carlson
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin.,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | - Daniel A Beard
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin.,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | - Julian H Lombard
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
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11
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Hashad AM, Sancho M, Brett SE, Welsh DG. Reactive Oxygen Species Mediate the Suppression of Arterial Smooth Muscle T-type Ca 2+ Channels by Angiotensin II. Sci Rep 2018; 8:3445. [PMID: 29472601 PMCID: PMC5823855 DOI: 10.1038/s41598-018-21899-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 02/13/2018] [Indexed: 02/07/2023] Open
Abstract
Vascular T-type Ca2+ channels (CaV3.1 and CaV3.2) play a key role in arterial tone development. This study investigated whether this conductance is a regulatory target of angiotensin II (Ang II), a vasoactive peptide that circulates and which is locally produced within the arterial wall. Patch clamp electrophysiology performed on rat cerebral arterial smooth muscle cells reveals that Ang II (100 nM) inhibited T-type currents through AT1 receptor activation. Blocking protein kinase C failed to eliminate channel suppression, a finding consistent with unique signaling proteins enabling this response. In this regard, inhibiting NADPH oxidase (Nox) with apocynin or ML171 (Nox1 selective) abolished channel suppression highlighting a role for reactive oxygen species (ROS). In the presence of Ni2+ (50 µM), Ang II failed to modulate the residual T-type current, an observation consistent with this peptide targeting CaV3.2. Selective channel suppression by Ang II impaired the ability of CaV3.2 to alter spontaneous transient outward currents or vessel diameter. Proximity ligation assay confirmed Nox1 colocalization with CaV3.2. In closing, Ang II targets CaV3.2 channels via a signaling pathway involving Nox1 and the generation of ROS. This unique regulatory mechanism alters BKCa mediated feedback giving rise to a “constrictive” phenotype often observed with cerebrovascular disease.
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Affiliation(s)
- Ahmed M Hashad
- Deptartment of Physiology & Pharmacology, Hotchkiss Brain and Libin Cardiovascular Institutes, University of Calgary, Alberta, Canada
| | - Maria Sancho
- Deptartment Physiology & Pharmacology, University of Western Ontario, London, Ontario, Canada
| | - Suzanne E Brett
- Deptartment Physiology & Pharmacology, University of Western Ontario, London, Ontario, Canada
| | - Donald G Welsh
- Deptartment of Physiology & Pharmacology, Hotchkiss Brain and Libin Cardiovascular Institutes, University of Calgary, Alberta, Canada. .,Deptartment Physiology & Pharmacology, University of Western Ontario, London, Ontario, Canada.
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12
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Freitas F, Estato V, Reis P, Castro-Faria-Neto HC, Carvalho V, Torres R, Lessa MA, Tibirica E. Acute simvastatin treatment restores cerebral functional capillary density and attenuates angiotensin II-induced microcirculatory changes in a model of primary hypertension. Microcirculation 2017; 24. [DOI: 10.1111/micc.12416] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 08/25/2017] [Indexed: 12/12/2022]
Affiliation(s)
- Felipe Freitas
- Laboratory of Cardiovascular Investigation; Oswaldo Cruz Institute; FIOCRUZ; Rio de Janeiro RJ Brazil
| | - Vanessa Estato
- Laboratory of Cardiovascular Investigation; Oswaldo Cruz Institute; FIOCRUZ; Rio de Janeiro RJ Brazil
| | - Patricia Reis
- Laboratory of Immunopharmacology; Oswaldo Cruz Institute; FIOCRUZ; Rio de Janeiro RJ Brazil
| | - Hugo C. Castro-Faria-Neto
- Laboratory of Immunopharmacology; Oswaldo Cruz Institute; FIOCRUZ; Rio de Janeiro RJ Brazil
- Estácio de Sá University; Rio de Janeiro Brazil
| | - Vinícius Carvalho
- Laboratory of Inflammation; Oswaldo Cruz Institute; FIOCRUZ; Rio de Janeiro RJ Brazil
| | - Rafael Torres
- Laboratory of Inflammation; Oswaldo Cruz Institute; FIOCRUZ; Rio de Janeiro RJ Brazil
| | - Marcos A. Lessa
- Laboratory of Cardiovascular Investigation; Oswaldo Cruz Institute; FIOCRUZ; Rio de Janeiro RJ Brazil
| | - Eduardo Tibirica
- Laboratory of Cardiovascular Investigation; Oswaldo Cruz Institute; FIOCRUZ; Rio de Janeiro RJ Brazil
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13
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Michel MC, Brunner HR, Foster C, Huo Y. Angiotensin II type 1 receptor antagonists in animal models of vascular, cardiac, metabolic and renal disease. Pharmacol Ther 2016; 164:1-81. [PMID: 27130806 DOI: 10.1016/j.pharmthera.2016.03.019] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 03/30/2016] [Indexed: 02/07/2023]
Abstract
We have reviewed the effects of angiotensin II type 1 receptor antagonists (ARBs) in various animal models of hypertension, atherosclerosis, cardiac function, hypertrophy and fibrosis, glucose and lipid metabolism, and renal function and morphology. Those of azilsartan and telmisartan have been included comprehensively whereas those of other ARBs have been included systematically but without intention of completeness. ARBs as a class lower blood pressure in established hypertension and prevent hypertension development in all applicable animal models except those with a markedly suppressed renin-angiotensin system; blood pressure lowering even persists for a considerable time after discontinuation of treatment. This translates into a reduced mortality, particularly in models exhibiting marked hypertension. The retrieved data on vascular, cardiac and renal function and morphology as well as on glucose and lipid metabolism are discussed to address three main questions: 1. Can ARB effects on blood vessels, heart, kidney and metabolic function be explained by blood pressure lowering alone or are they additionally directly related to blockade of the renin-angiotensin system? 2. Are they shared by other inhibitors of the renin-angiotensin system, e.g. angiotensin converting enzyme inhibitors? 3. Are some effects specific for one or more compounds within the ARB class? Taken together these data profile ARBs as a drug class with unique properties that have beneficial effects far beyond those on blood pressure reduction and, in some cases distinct from those of angiotensin converting enzyme inhibitors. The clinical relevance of angiotensin receptor-independent effects of some ARBs remains to be determined.
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Affiliation(s)
- Martin C Michel
- Dept. Pharmacology, Johannes Gutenberg University, Mainz, Germany; Dept. Translational Medicine & Clinical Pharmacology, Boehringer Ingelheim, Ingelheim, Germany.
| | | | - Carolyn Foster
- Retiree from Dept. of Research Networking, Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, CT, USA
| | - Yong Huo
- Dept. Cardiology & Heart Center, Peking University First Hospital, Beijing, PR China
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14
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Canavero I, Sherburne HA, Tremble SM, Clark WM, Cipolla MJ. Effects of Acute Stroke Serum on Non-Ischemic Cerebral and Mesenteric Vascular Function. Transl Stroke Res 2016; 7:156-65. [PMID: 26809954 DOI: 10.1007/s12975-016-0449-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 12/17/2015] [Accepted: 01/08/2016] [Indexed: 02/03/2023]
Abstract
We investigated the effects of circulating factors in serum obtained from patients in the acute phase of different subtypes of ischemic stroke on non-ischemic cerebral and mesenteric arteries, as a potential mechanism involved in influencing regional perfusion and thus clinical evolution. Posterior cerebral arteries (PCAs) and mesentery arteries (MAs) isolated from Wistar Kyoto rats were perfused with serum from acute stroke patients with large vessel disease without (LVD) or with hypertension (LVD + HTN), cardioembolism with hypertension (CE + HTN), or physiologic saline as controls. Myogenic activity and nitric oxide-dependent vasorelaxation were assessed after 2 h of intraluminal exposure to serum. Vascular function was differentially affected by sera. Exposure to LVD serum increased myogenic tone and produced endothelial dysfunction in both PCAs and MAs. However, CE + HTN serum increased tone and decreased smooth muscle sensitivity to NO in vessels from both vascular beds. LVD + HTN serum was associated with reduced smooth muscle sensitivity to NO in vessels from both vascular beds but increased tone only in PCAs. Inflammation and oxidative stress, determined by measurement of high sensitivity C-reactive protein, uric acid, and free 8-isoprostane, were enhanced in all the serum groups. These results demonstrate vasoactive properties of acute stroke serum related to stroke subtypes that could potentially contribute to the pathogenesis of early hemodynamic-based clinical events.
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Affiliation(s)
- Isabella Canavero
- Department of Neurological Sciences, University of Vermont College of Medicine, 149 Beaumont Ave., HSRF 416A, Burlington, VT, 05405, USA
| | - Helene A Sherburne
- Department of Neurological Sciences, University of Vermont College of Medicine, 149 Beaumont Ave., HSRF 416A, Burlington, VT, 05405, USA
| | - Sarah M Tremble
- Department of Neurological Sciences, University of Vermont College of Medicine, 149 Beaumont Ave., HSRF 416A, Burlington, VT, 05405, USA
| | - Wayne M Clark
- Department of Neurology, Oregon Stroke Center, Oregon Health and Science University, Portland, OR, USA
| | - Marilyn J Cipolla
- Department of Neurological Sciences, University of Vermont College of Medicine, 149 Beaumont Ave., HSRF 416A, Burlington, VT, 05405, USA. .,Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Vermont College of Medicine, Burlington, VT, USA. .,Department of Pharmacology, University of Vermont College of Medicine, Burlington, VT, USA.
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15
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Putilina MV. [Chronic cerebral ischemia associated with Raynaud's syndrome]. Zh Nevrol Psikhiatr Im S S Korsakova 2015; 115:90-96. [PMID: 26356403 DOI: 10.17116/jnevro20151156190-96] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Over the last years, a number of patients with chronic cerebral ischemia has been increased significantly. Compensatory possibilities of the brain and cerebral circulatory system are so great that even serious disturbances of blood circulation could not cause clinical signs of brain dysfunction for a long time. At the same time, long-term ischemia can lead to peripheral local disturbances of microcirculation that is appears to be a first signal of the problems with homeostasis. Therefore, Raynaud's syndrome may be one of the predictors of standard symptoms of chronic cerebral ischemia (CCI). This phenomenon is explicitly considered as a sign of blood circulation impairment while the pathogenetic mechanism of vascular arterial bed instability is completely ignored. Detailed study of clinical correlations of Raynaud's syndrome in CCI would help to develop a common pharmacotherapeutic approach to its treatment.
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Affiliation(s)
- M V Putilina
- Pirogov Russian National Research Medical University, Moscow
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16
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McCarthy CA, Facey LJ, Widdop RE. The protective arms of the renin-angiontensin system in stroke. Curr Hypertens Rep 2015; 16:440. [PMID: 24816974 DOI: 10.1007/s11906-014-0440-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
It is quite well established that activation of the so-called protective arms of the renin-angiotensin system (RAS), involving both AT2 and Mas receptors, provides a counter-regulatory role to AT1 receptor overactivity that may drive pathological changes in the cardiovascular system. In this brief review, we will focus on recent evidence that identifies at least three different pathways that may be effective in the setting of stroke and may be complementary with AT1 receptor blockade. Such mechanisms include AT2 receptor stimulation, Mas receptor stimulation and insulin-regulated aminopeptidase blockade. This report highlights recent data demonstrating striking neuroprotective effects in preclinical models of stroke targeting each of these pathways, which may pave the way for translational opportunities in this field.
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Affiliation(s)
- Claudia A McCarthy
- Department of Pharmacology, Monash University, Clayton, Victoria, 3800, Australia
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17
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Votava-Smith JK, Habli M, Cnota JF, Divanovic A, Polzin W, Lim FY, Michelfelder EC. Diastolic dysfunction and cerebrovascular redistribution precede overt recipient twin cardiomyopathy in early-stage twin-twin transfusion syndrome. J Am Soc Echocardiogr 2015; 28:533-40. [PMID: 25577184 DOI: 10.1016/j.echo.2014.12.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Indexed: 11/16/2022]
Abstract
BACKGROUND Indications for intervention in early-stage (Quintero I and II) twin-twin transfusion syndrome (TTTS) are not standardized. Fetal echocardiography can be used to guide the management of early-stage patients. The aim of this study was to identify early cardiovascular findings that may precede progression to overt recipient twin (RT) cardiomyopathy in early-stage TTTS. METHODS This was a retrospective review of pregnancies evaluated from 2004 to 2010. Subjects were included when initial evaluation identified Quintero I or II TTTS without evidence of "overt" RT cardiomyopathy, defined on the basis of atrioventricular valve regurgitation, ventricular hypertrophy, and abnormal Doppler myocardial performance indices. Patients elected management with observation or amnioreduction. Pregnancies were grouped by whether the RT developed overt cardiomyopathy. Initial values, including myocardial performance index, diastolic filling time corrected for heart rate (Doppler inflow duration/cardiac cycle length), pulsatility indices of the ductus venosus, umbilical artery, and middle cerebral artery, and cerebroplacental ratio (middle cerebral artery PI/umbilical artery PI), were compared. RESULTS Of 174 pregnancies evaluated with early-stage TTTS, 45 (26%) did not show evidence of RT cardiomyopathy. Follow-up echocardiography identified cardiomyopathy in 20 of 45 RTs (44%). Those RTs with subsequent cardiomyopathy had shorter diastolic filling times corrected for heart rate, higher ductus venosus PIs, lower middle cerebral artery PIs, and lower cerebroplacental ratios on initial echocardiography. CONCLUSION Diastolic dysfunction and cerebroplacental redistribution precede findings of overt cardiomyopathy in RTs with early-stage TTTS. Assessment of these parameters may allow earlier identification of RTs with cardiac disease and help guide management. Prospective studies are needed to assess the role of echocardiography in patient selection for the treatment of early-stage TTTS.
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Affiliation(s)
- Jodie K Votava-Smith
- Fetal Heart Program, The Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Mounira Habli
- Fetal Care Center of Cincinnati, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - James F Cnota
- Fetal Heart Program, The Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Allison Divanovic
- Fetal Heart Program, The Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - William Polzin
- Fetal Care Center of Cincinnati, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Foong-Yen Lim
- Fetal Care Center of Cincinnati, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Erik C Michelfelder
- Fetal Heart Program, The Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.
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18
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De Silva TM, Ketsawatsomkron P, Pelham C, Sigmund CD, Faraci FM. Genetic interference with peroxisome proliferator-activated receptor γ in smooth muscle enhances myogenic tone in the cerebrovasculature via A Rho kinase-dependent mechanism. Hypertension 2014; 65:345-51. [PMID: 25385762 DOI: 10.1161/hypertensionaha.114.04541] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Myogenic responses by resistance vessels are a key component of autoregulation in brain, thus playing a crucial role in regulating cerebral blood flow and protecting the blood-brain barrier against potentially detrimental elevations in blood pressure. Although cerebrovascular disease is often accompanied by alterations in myogenic responses, mechanisms that control these changes are poorly understood. Peroxisome proliferator-activated receptor γ has emerged as a regulator of vascular tone. We hypothesized that interference with peroxisome proliferator-activated receptor γ in smooth muscle would augment myogenic responses in cerebral arteries. We studied transgenic mice expressing a dominant-negative mutation in peroxisome proliferator-activated receptor γ selectively in smooth muscle (S-P467L) and nontransgenic littermates. Myogenic tone in middle cerebral arteries from S-P467L was elevated 3-fold when compared with nontransgenic littermates. Rho kinase is thought to play a major role in cerebrovascular disease. The Rho kinase inhibitor, Y-27632, abolished augmented myogenic tone in middle cerebral arteries from S-P467L mice. CN-03, which modifies RhoA making it constitutively active, elevated myogenic tone to ≈60% in both strains, via a Y-27632-dependent mechanism. Large conductance Ca(2+)-activated K(+) channels (BKCa) modulate myogenic tone. Inhibitors of BKCa caused greater constriction in middle cerebral arteries from nontransgenic littermates when compared with S-P467L. Expression of RhoA or Rho kinase-I/II protein was similar in cerebral arteries from S-P467L mice. Overall, the data suggest that peroxisome proliferator-activated receptor γ in smooth muscle normally inhibits Rho kinase and promotes BKCa function, thus influencing myogenic tone in resistance arteries in brain. These findings have implications for mechanisms that underlie large- and small-vessel disease in brain, as well as regulation of cerebral blood flow.
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Affiliation(s)
- T Michael De Silva
- From the Departments of Internal Medicine (T.M.D.S., C.D.S, F.M.F.) and Pharmacology (P.K., C.P., C.D.S., F.M.F.), Francois M. Abboud Cardiovascular Center, The University of Iowa Carver College of Medicine; and Veterans Affairs Healthcare System, Iowa City, IA (F.M.F.)
| | - Pimonrat Ketsawatsomkron
- From the Departments of Internal Medicine (T.M.D.S., C.D.S, F.M.F.) and Pharmacology (P.K., C.P., C.D.S., F.M.F.), Francois M. Abboud Cardiovascular Center, The University of Iowa Carver College of Medicine; and Veterans Affairs Healthcare System, Iowa City, IA (F.M.F.)
| | - Christopher Pelham
- From the Departments of Internal Medicine (T.M.D.S., C.D.S, F.M.F.) and Pharmacology (P.K., C.P., C.D.S., F.M.F.), Francois M. Abboud Cardiovascular Center, The University of Iowa Carver College of Medicine; and Veterans Affairs Healthcare System, Iowa City, IA (F.M.F.)
| | - Curt D Sigmund
- From the Departments of Internal Medicine (T.M.D.S., C.D.S, F.M.F.) and Pharmacology (P.K., C.P., C.D.S., F.M.F.), Francois M. Abboud Cardiovascular Center, The University of Iowa Carver College of Medicine; and Veterans Affairs Healthcare System, Iowa City, IA (F.M.F.)
| | - Frank M Faraci
- From the Departments of Internal Medicine (T.M.D.S., C.D.S, F.M.F.) and Pharmacology (P.K., C.P., C.D.S., F.M.F.), Francois M. Abboud Cardiovascular Center, The University of Iowa Carver College of Medicine; and Veterans Affairs Healthcare System, Iowa City, IA (F.M.F.).
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19
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Miller AA, Maxwell KF, Chrissobolis S, Bullen ML, Ku JM, Michael De Silva T, Selemidis S, Hooker EU, Drummond GR, Sobey CG, Kemp-Harper BK. Nitroxyl (HNO) suppresses vascular Nox2 oxidase activity. Free Radic Biol Med 2013; 60:264-71. [PMID: 23459072 DOI: 10.1016/j.freeradbiomed.2013.02.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Revised: 02/18/2013] [Accepted: 02/22/2013] [Indexed: 11/19/2022]
Abstract
Nox2 oxidase activity underlies the oxidative stress and vascular dysfunction associated with several vascular-related diseases. We have reported that nitric oxide (NO) decreases reactive oxygen species production by endothelial Nox2. This study tested the hypothesis that nitroxyl (HNO), the redox sibling of NO, also suppresses vascular Nox2 oxidase activity. Specifically, we examined the influence of two well-characterized HNO donors, Angeli's salt and isopropylamine NONOate (IPA/NO), on Nox2-dependent responses to angiotensin II (reactive oxygen species production and vasoconstriction) in mouse cerebral arteries. Angiotensin II (0.1μmol/L)-stimulated superoxide (measured by lucigenin-enhanced chemiluminescence) and hydrogen peroxide (Amplex red fluorescence) levels in cerebral arteries (pooled basilar and middle cerebral (MCA)) from wild-type (WT) mice were ~60% lower (P<0.05) in the presence of either Angeli's salt (1μmol/L) or IPA/NO (1μmol/L). Similarly, phorbyl 12,13-dibutyrate (10μmol/L; Nox2 activator)-stimulated hydrogen peroxide levels were ~40% lower in the presence of IPA/NO (1μmol/L; P<0.05). The ability of IPA/NO to decrease superoxide levels was reversible and abolished by the HNO scavenger l-cysteine (3mmol/L; P<0.05), but was unaffected by hydroxocobalamin (100μmol/L; NO scavenger), ODQ (10μmol/L; soluble guanylyl cyclase (sGC) inhibitor), or Rp-8-pCPT-cGMPS (10μmol/L; cyclic guanosine monophosphate (cGMP)-dependent protein kinase inhibitor). Angiotensin II-stimulated superoxide was substantially less in arteries from Nox2-deficient (Nox2(-/y)) versus WT mice (P<0.05). In contrast to WT, IPA/NO (1μmol/L) had no effect on superoxide levels in arteries from Nox2(-/y) mice. Finally, angiotensin II (1-1000μmol/L)-induced constriction of WT MCA was virtually abolished by IPA/NO (1μmol/L), whereas constrictor responses to either the thromboxane A2 mimetic U46619 (1-100 nmol/L) or high potassium (122.7mmol/L) were unaffected. In conclusion, HNO suppresses vascular Nox2 oxidase activity via a sGC-cGMP-independent pathway. Thus, HNO donors might be useful therapeutic agents to limit and/or prevent Nox2-dependent vascular dysfunction.
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Affiliation(s)
- Alyson A Miller
- Vascular Biology and Immunopharmacology Group, Department of Pharmacology, Monash University, Melbourne, VIC 3800, Australia
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20
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Foulquier S, Steckelings UM, Unger T. Impact of the AT(2) receptor agonist C21 on blood pressure and beyond. Curr Hypertens Rep 2013; 14:403-9. [PMID: 22836386 DOI: 10.1007/s11906-012-0291-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
It is now widely accepted that the angiotensin AT(2) receptor (AT(2)R) plays an important protective role during pathophysiologic conditions, acting as a repair system. The development of the first selective nonpeptide AT(2)R agonist C21 accelerated our understanding of AT(2)R-mediated protective signaling and actions. This article reviews the impact of C21 on blood pressure in normotensive and hypertensive animal models. Although C21 does not act as a classical antihypertensive drug, it could be useful in preventing hypertension-induced vascular and other end organ damages via anti-apoptotic, anti-fibrotic and anti-inflammatory actions. In particular, a strong body of evidence started to emerge around its anti-inflammatory feature. This property should be further investigated for potential clinical indications in cardiovascular diseases and beyond.
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Affiliation(s)
- Sébastien Foulquier
- Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands.
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21
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De Silva TM, Faraci FM. Effects of angiotensin II on the cerebral circulation: role of oxidative stress. Front Physiol 2013; 3:484. [PMID: 23316164 PMCID: PMC3539653 DOI: 10.3389/fphys.2012.00484] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 12/11/2012] [Indexed: 12/31/2022] Open
Abstract
Oxidative stress has emerged as a key component of many diseases that affect the vasculature. Oxidative stress is characterized as a cellular environment where the generation of oxidant molecules overwhelms endogenous anti-oxidant defense mechanisms. NADPH oxidases are a family of enzymes whose primary purpose is generation of reactive oxygen species (oxidant molecules) and therefore are likely to be key contributors to oxidative stress. Hypertension is associated with oxidative stress in the vasculature and is a major risk factor for stroke and cognitive abnormalities. Angiotensin II (Ang II) is the main effector peptide of the renin-angiotensin system (RAS) and plays a critical role in promoting oxidative stress in the vasculature. In the cerebral circulation, Ang II has been implicated in reactive oxygen species generation, alterations to vasomotor function, impaired neurovascular coupling, inflammation, and vascular remodeling. Furthermore, studies in humans have shown that cerebral blood flow is altered during hypertension and therapeutically targeting the RAS improves cerebral blood flow. Importantly, many of the aforementioned effects have been shown to be dependent on NADPH oxidases. Thus, Ang II, NADPH oxidases and oxidative stress are likely to play key roles in the pathogenesis of hypertension and associated cerebrovascular disease. This review will focus on our current understanding of the contribution of Ang II and NADPH oxidases to oxidative stress in the cerebral circulation.
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Affiliation(s)
- T Michael De Silva
- Department of Internal Medicine, Cardiovascular Center, The University of Iowa Carver College of Medicine Iowa City, IA, USA
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22
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McCarthy CA, Vinh A, Broughton BRS, Sobey CG, Callaway JK, Widdop RE. Angiotensin II Type 2 Receptor Stimulation Initiated After Stroke Causes Neuroprotection in Conscious Rats. Hypertension 2012. [DOI: 10.1161/hypertensionaha.112.199646 and 1880=1880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
We have demonstrated previously that pretreatment with an angiotensin II type 2 receptor (AT
2
R) agonist is neuroprotective against a subsequent stroke independent of any changes in blood pressure. Therefore, in the current study, we have examined the potential neuroprotective effect of AT
2
R stimulation initiated after stroke induction to mimic the clinical setting. Intracerebroventricular administration of the AT
2
R agonist CGP42112 was commenced 6 hours after an ischemic stroke had been induced in conscious spontaneously hypertensive rats. CGP42112 given over 4 doses in the same rats (3 µg/kg per dose centrally) at 6, 24, 48, and 72 hours after stroke induction reduced total infarct volume (32±13 mm
3
versus vehicle, 170±49 mm
3
;
P
<0.05) and improved motor function. Furthermore, we have demonstrated that AT
2
R stimulation after stroke increased neuronal survival, decreased apoptosis, and caused an increase in the number of activated microglia in the core region of damage. The effects of CGP42112 were partially reversed with the coadministration of an AT
2
R antagonist, PD123319. Thus, the current study has shown for the first time that delayed central AT
2
R stimulation after a cerebral incident is neuroprotective in a conscious rat model of stroke.
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Affiliation(s)
- Claudia A. McCarthy
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Antony Vinh
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Brad R. S. Broughton
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Christopher G. Sobey
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Jennifer K. Callaway
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Robert E. Widdop
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
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McCarthy CA, Vinh A, Broughton BRS, Sobey CG, Callaway JK, Widdop RE. Angiotensin II Type 2 Receptor Stimulation Initiated After Stroke Causes Neuroprotection in Conscious Rats. Hypertension 2012. [DOI: 10.1161/hypertensionaha.112.199646 order by 8029-- #] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
We have demonstrated previously that pretreatment with an angiotensin II type 2 receptor (AT
2
R) agonist is neuroprotective against a subsequent stroke independent of any changes in blood pressure. Therefore, in the current study, we have examined the potential neuroprotective effect of AT
2
R stimulation initiated after stroke induction to mimic the clinical setting. Intracerebroventricular administration of the AT
2
R agonist CGP42112 was commenced 6 hours after an ischemic stroke had been induced in conscious spontaneously hypertensive rats. CGP42112 given over 4 doses in the same rats (3 µg/kg per dose centrally) at 6, 24, 48, and 72 hours after stroke induction reduced total infarct volume (32±13 mm
3
versus vehicle, 170±49 mm
3
;
P
<0.05) and improved motor function. Furthermore, we have demonstrated that AT
2
R stimulation after stroke increased neuronal survival, decreased apoptosis, and caused an increase in the number of activated microglia in the core region of damage. The effects of CGP42112 were partially reversed with the coadministration of an AT
2
R antagonist, PD123319. Thus, the current study has shown for the first time that delayed central AT
2
R stimulation after a cerebral incident is neuroprotective in a conscious rat model of stroke.
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Affiliation(s)
- Claudia A. McCarthy
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Antony Vinh
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Brad R. S. Broughton
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Christopher G. Sobey
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Jennifer K. Callaway
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Robert E. Widdop
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
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24
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McCarthy CA, Vinh A, Broughton BRS, Sobey CG, Callaway JK, Widdop RE. Angiotensin II Type 2 Receptor Stimulation Initiated After Stroke Causes Neuroprotection in Conscious Rats. Hypertension 2012. [DOI: 10.1161/hypertensionaha.112.199646 order by 8029-- -] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
We have demonstrated previously that pretreatment with an angiotensin II type 2 receptor (AT
2
R) agonist is neuroprotective against a subsequent stroke independent of any changes in blood pressure. Therefore, in the current study, we have examined the potential neuroprotective effect of AT
2
R stimulation initiated after stroke induction to mimic the clinical setting. Intracerebroventricular administration of the AT
2
R agonist CGP42112 was commenced 6 hours after an ischemic stroke had been induced in conscious spontaneously hypertensive rats. CGP42112 given over 4 doses in the same rats (3 µg/kg per dose centrally) at 6, 24, 48, and 72 hours after stroke induction reduced total infarct volume (32±13 mm
3
versus vehicle, 170±49 mm
3
;
P
<0.05) and improved motor function. Furthermore, we have demonstrated that AT
2
R stimulation after stroke increased neuronal survival, decreased apoptosis, and caused an increase in the number of activated microglia in the core region of damage. The effects of CGP42112 were partially reversed with the coadministration of an AT
2
R antagonist, PD123319. Thus, the current study has shown for the first time that delayed central AT
2
R stimulation after a cerebral incident is neuroprotective in a conscious rat model of stroke.
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Affiliation(s)
- Claudia A. McCarthy
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Antony Vinh
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Brad R. S. Broughton
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Christopher G. Sobey
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Jennifer K. Callaway
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Robert E. Widdop
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
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25
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McCarthy CA, Vinh A, Broughton BRS, Sobey CG, Callaway JK, Widdop RE. Angiotensin II Type 2 Receptor Stimulation Initiated After Stroke Causes Neuroprotection in Conscious Rats. Hypertension 2012. [DOI: 10.1161/hypertensionaha.112.199646 order by 1-- gadu] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
We have demonstrated previously that pretreatment with an angiotensin II type 2 receptor (AT
2
R) agonist is neuroprotective against a subsequent stroke independent of any changes in blood pressure. Therefore, in the current study, we have examined the potential neuroprotective effect of AT
2
R stimulation initiated after stroke induction to mimic the clinical setting. Intracerebroventricular administration of the AT
2
R agonist CGP42112 was commenced 6 hours after an ischemic stroke had been induced in conscious spontaneously hypertensive rats. CGP42112 given over 4 doses in the same rats (3 µg/kg per dose centrally) at 6, 24, 48, and 72 hours after stroke induction reduced total infarct volume (32±13 mm
3
versus vehicle, 170±49 mm
3
;
P
<0.05) and improved motor function. Furthermore, we have demonstrated that AT
2
R stimulation after stroke increased neuronal survival, decreased apoptosis, and caused an increase in the number of activated microglia in the core region of damage. The effects of CGP42112 were partially reversed with the coadministration of an AT
2
R antagonist, PD123319. Thus, the current study has shown for the first time that delayed central AT
2
R stimulation after a cerebral incident is neuroprotective in a conscious rat model of stroke.
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Affiliation(s)
- Claudia A. McCarthy
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Antony Vinh
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Brad R. S. Broughton
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Christopher G. Sobey
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Jennifer K. Callaway
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Robert E. Widdop
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
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26
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McCarthy CA, Vinh A, Broughton BRS, Sobey CG, Callaway JK, Widdop RE. Angiotensin II Type 2 Receptor Stimulation Initiated After Stroke Causes Neuroprotection in Conscious Rats. Hypertension 2012. [DOI: 10.1161/hypertensionaha.112.199646 order by 8029-- awyx] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
We have demonstrated previously that pretreatment with an angiotensin II type 2 receptor (AT
2
R) agonist is neuroprotective against a subsequent stroke independent of any changes in blood pressure. Therefore, in the current study, we have examined the potential neuroprotective effect of AT
2
R stimulation initiated after stroke induction to mimic the clinical setting. Intracerebroventricular administration of the AT
2
R agonist CGP42112 was commenced 6 hours after an ischemic stroke had been induced in conscious spontaneously hypertensive rats. CGP42112 given over 4 doses in the same rats (3 µg/kg per dose centrally) at 6, 24, 48, and 72 hours after stroke induction reduced total infarct volume (32±13 mm
3
versus vehicle, 170±49 mm
3
;
P
<0.05) and improved motor function. Furthermore, we have demonstrated that AT
2
R stimulation after stroke increased neuronal survival, decreased apoptosis, and caused an increase in the number of activated microglia in the core region of damage. The effects of CGP42112 were partially reversed with the coadministration of an AT
2
R antagonist, PD123319. Thus, the current study has shown for the first time that delayed central AT
2
R stimulation after a cerebral incident is neuroprotective in a conscious rat model of stroke.
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Affiliation(s)
- Claudia A. McCarthy
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Antony Vinh
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Brad R. S. Broughton
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Christopher G. Sobey
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Jennifer K. Callaway
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Robert E. Widdop
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
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27
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McCarthy CA, Vinh A, Broughton BRS, Sobey CG, Callaway JK, Widdop RE. Angiotensin II Type 2 Receptor Stimulation Initiated After Stroke Causes Neuroprotection in Conscious Rats. Hypertension 2012. [DOI: 10.1161/hypertensionaha.112.199646 order by 1-- #] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
We have demonstrated previously that pretreatment with an angiotensin II type 2 receptor (AT
2
R) agonist is neuroprotective against a subsequent stroke independent of any changes in blood pressure. Therefore, in the current study, we have examined the potential neuroprotective effect of AT
2
R stimulation initiated after stroke induction to mimic the clinical setting. Intracerebroventricular administration of the AT
2
R agonist CGP42112 was commenced 6 hours after an ischemic stroke had been induced in conscious spontaneously hypertensive rats. CGP42112 given over 4 doses in the same rats (3 µg/kg per dose centrally) at 6, 24, 48, and 72 hours after stroke induction reduced total infarct volume (32±13 mm
3
versus vehicle, 170±49 mm
3
;
P
<0.05) and improved motor function. Furthermore, we have demonstrated that AT
2
R stimulation after stroke increased neuronal survival, decreased apoptosis, and caused an increase in the number of activated microglia in the core region of damage. The effects of CGP42112 were partially reversed with the coadministration of an AT
2
R antagonist, PD123319. Thus, the current study has shown for the first time that delayed central AT
2
R stimulation after a cerebral incident is neuroprotective in a conscious rat model of stroke.
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Affiliation(s)
- Claudia A. McCarthy
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Antony Vinh
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Brad R. S. Broughton
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Christopher G. Sobey
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Jennifer K. Callaway
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Robert E. Widdop
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
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28
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McCarthy CA, Vinh A, Broughton BRS, Sobey CG, Callaway JK, Widdop RE. Angiotensin II Type 2 Receptor Stimulation Initiated After Stroke Causes Neuroprotection in Conscious Rats. Hypertension 2012. [DOI: 10.1161/hypertensionaha.112.199646 order by 1-- -] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
We have demonstrated previously that pretreatment with an angiotensin II type 2 receptor (AT
2
R) agonist is neuroprotective against a subsequent stroke independent of any changes in blood pressure. Therefore, in the current study, we have examined the potential neuroprotective effect of AT
2
R stimulation initiated after stroke induction to mimic the clinical setting. Intracerebroventricular administration of the AT
2
R agonist CGP42112 was commenced 6 hours after an ischemic stroke had been induced in conscious spontaneously hypertensive rats. CGP42112 given over 4 doses in the same rats (3 µg/kg per dose centrally) at 6, 24, 48, and 72 hours after stroke induction reduced total infarct volume (32±13 mm
3
versus vehicle, 170±49 mm
3
;
P
<0.05) and improved motor function. Furthermore, we have demonstrated that AT
2
R stimulation after stroke increased neuronal survival, decreased apoptosis, and caused an increase in the number of activated microglia in the core region of damage. The effects of CGP42112 were partially reversed with the coadministration of an AT
2
R antagonist, PD123319. Thus, the current study has shown for the first time that delayed central AT
2
R stimulation after a cerebral incident is neuroprotective in a conscious rat model of stroke.
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Affiliation(s)
- Claudia A. McCarthy
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Antony Vinh
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Brad R. S. Broughton
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Christopher G. Sobey
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Jennifer K. Callaway
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
| | - Robert E. Widdop
- From the Department of Pharmacology, Monash University, Clayton, Victoria, Australia (C.A.M., A.V., B.R.S.B., C.G.S., R.E.W.); Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia (J.K.C.)
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McCarthy CA, Vinh A, Broughton BRS, Sobey CG, Callaway JK, Widdop RE. Angiotensin II type 2 receptor stimulation initiated after stroke causes neuroprotection in conscious rats. Hypertension 2012; 60:1531-7. [PMID: 23090772 DOI: 10.1161/hypertensionaha.112.199646] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
We have demonstrated previously that pretreatment with an angiotensin II type 2 receptor (AT(2)R) agonist is neuroprotective against a subsequent stroke independent of any changes in blood pressure. Therefore, in the current study, we have examined the potential neuroprotective effect of AT(2)R stimulation initiated after stroke induction to mimic the clinical setting. Intracerebroventricular administration of the AT(2)R agonist CGP42112 was commenced 6 hours after an ischemic stroke had been induced in conscious spontaneously hypertensive rats. CGP42112 given over 4 doses in the same rats (3 µg/kg per dose centrally) at 6, 24, 48, and 72 hours after stroke induction reduced total infarct volume (32 ± 13 mm(3) versus vehicle, 170 ± 49 mm(3); P<0.05) and improved motor function. Furthermore, we have demonstrated that AT(2)R stimulation after stroke increased neuronal survival, decreased apoptosis, and caused an increase in the number of activated microglia in the core region of damage. The effects of CGP42112 were partially reversed with the coadministration of an AT(2)R antagonist, PD123319. Thus, the current study has shown for the first time that delayed central AT(2)R stimulation after a cerebral incident is neuroprotective in a conscious rat model of stroke.
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Affiliation(s)
- Claudia A McCarthy
- Department of Pharmacology, Monash University, Clayton, Victoria, Australia.
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Differential effects of short-term treatment with two AT1 receptor blockers on diameter of pial arterioles in SHR. PLoS One 2012; 7:e42469. [PMID: 22957022 PMCID: PMC3434186 DOI: 10.1371/journal.pone.0042469] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Accepted: 07/09/2012] [Indexed: 11/19/2022] Open
Abstract
Chronic treatment with angiotensin receptor blockers is largely accepted for protecting cerebral circulation during hypertension, but beneficial effects of short-term treatments are questionable, as highlighted by the recent SCAST trial. We compared the impact of 10 days treatment with candesartan (as SCAST) versus telmisartan (previously described to reverse arteriolar remodeling, chronic treatment) on pial arterioles of spontaneously hypertensive rats (SHR). We explored whether PPAR-gamma agonist activity or AT(1) receptor blockade are involved in their differential effects. In the first study, 4-month-old male SHR were treated with telmisartan (TELMI, 2 mg/kg per day) or candesartan cilexetil (CANDE, 10 mg/kg per day) and compared to vehicle treated SHR and normotensive WKY. In a second study, SHR were treated with CANDE, pioglitazone (a PPAR-gamma agonist, PIO 2.5 mg/kg per day) or CANDE+PIO, compared to TELMI. Internal diameter of pial arterioles (ID, cranial window) was measured at baseline, during hemorrhage-induced hypotension, or following suffusion of Ang II (10(-6) mol/L) or EDTA inactivation of smooth muscle cells (passive ID). PPAR-gamma and eNOS (target gene of PPAR-gamma) mRNA were evaluated in brain microvessels. For similar antihypertensive effects, TELMI (+44% versus SHR), but not CANDE, increased baseline ID. During hemorrhage, ID in TELMI group was similar to WKY, while ID in SHR and CANDE remained lower. In the second study, TELMI (+36%, versus SHR) and CANDE+PIO (+43%) increased baseline ID, but not CANDE or PIO alone. TELMI (-66%) and CANDE+PIO (-69%), but neither CANDE nor PIO alone, decreased Ang II-induced vasoconstriction. CANDE+PIO, but not CANDE, increased passive ID. In both studies, PPAR-gamma and eNOS expressions were higher in TELMI than CANDE. Short-term treatment with TELMI, but not with CANDE, reverses narrowing of pial arteriolar ID in SHR. This may involve PPAR-gamma related mechanisms, since CANDE+PIO treatment induced similar effects, and a better blockade of AT(1) receptors.
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Abstract
BACKGROUND Angiotensin II (Ang II) induces constriction (AT(1)) and dilation (AT(2) receptors) of cerebral arterioles. High sodium intake induces changes in receptors expression and loss of AT(2)-mediated vasodilation in extracerebral vessels. We investigated whether high salt modifies the AT(2)-mediated response of cerebral arterioles. METHODS Three-month-old male Wistar rats received drinking water supplemented or not with 1% NaCl. We measured at day 4 or 30 plasma aldosterone concentration, AT receptors expression (brain microvessels, western blot, RT-qPCR), internal diameter of pial arterioles (cranial window) following suffusion with Ang II (10(-6) mol/l, or 10(-8) mol/l + losartan 10(-5) mol/l), serotonin (5-HT, 10(-6) mol/l), sodium nitroprusside (10(-5) mol/l) and adenosine diphosphate (ADP, 10(-4) mol/l). RESULTS High salt did not modify arterial pressure, baseline arteriolar diameter, vasoconstriction to Ang II or 5-HT, nor vasodilation to SNP. High salt lowered plasma aldosterone concentration (d4 138 ± 71 not significant vs. control 338 ± 73; d30 150 ± 21 P < 0.05 vs. control 517 ± 79 μmol/l). AT receptors mRNA did not change while protein level of AT(2) receptors decreased at d4 (64 ± 9% of control, P < 0.05). AT(2)-mediated vasodilation (control d4; d30 8 ± 2; 5 ± 2%) was abolished at d4 (-2 ± 2%, P < 0.05) and reversed to vasoconstriction at d30 (-7 ± 2%, P < 0.05). ADP-induced vasodilation is abolished at d30 (2 ± 2, P < 0.05 vs. control 19 ± 4%). CONCLUSION High salt specifically abolishes AT(2)-mediated vasodilation, immediately, via decreased level of AT(2) receptor protein, and after 30 days, in association with abolition of endothelial vasodilation. Such loss of AT(2)-mediated vasodilation may be deleterious in case of stroke.
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32
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Atkinson J. Stroke, high blood pressure and the Renin-Angiotensin-aldosterone system - new developments. Front Pharmacol 2011; 2:22. [PMID: 21687514 PMCID: PMC3108479 DOI: 10.3389/fphar.2011.00022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2011] [Accepted: 04/06/2011] [Indexed: 01/13/2023] Open
Abstract
This review considers whether a case can be made for a protective effect of inhibitors and blockers of the renin-angiotensin-aldosterone system (RAAS) on the cerebral circulation. It first looks at whether there exists a preferential effect on the cerebral circulation during a drug-induced lowering of high arterial blood pressure and cardiovascular morbi-mortality. It then goes on to consider background studies on the relationship between inhibition of the RAAS and stroke. This is followed by exploration of possible new directions in the inhibition of the RAAS and its effect on stroke.
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Affiliation(s)
- Jeffrey Atkinson
- Pharmacology Laboratory, Pharmacy Faculty, Nancy UniversityVillers, France
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Knecht KR, Leffler CW. Distinct effects of intravascular and extravascular angiotensin II on cerebrovascular circulation of newborn pigs. Exp Biol Med (Maywood) 2011; 235:1479-88. [PMID: 21127344 DOI: 10.1258/ebm.2010.010149] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Angiotensin II (AngII) is important in regulation of vascular resistance and control of blood flow among organs and tissues. The effect of AngII on the cerebral microvasculature may be mediated or altered by endothelial-derived signals. The aim of this study was to test the hypothesis that blood AngII dilates neonatal pial arterioles via an endothelial-dependent mechanism but brain AngII can constrict pial arterioles by activating smooth muscle AT1 receptors. Studies used anesthetized newborn pigs with surgically implanted closed cranial windows. AngII was given either by infusion into the carotid artery ipsilateral to the cranial window or topically. Intracarotid infusion of AngII dilated pial arterioles. The dilation was blocked by systemic administration of the AT1-receptor antagonist, losartan, but unaffected by topical losartan. Topical AngII also caused dilation, but this dilation was converted to constriction by topical losartan. In piglets pretreated with the angiotensin-converting enzyme (ACE) inhibitor, enalapril, topical AngII constricted, rather than dilated, pial arterioles. In enalapril-treated piglets, light/dye endothelial injury blocked dilation to intracarotid AngII but did not affect constriction to topical AngII. Either indomethacin or l-nitroarginine methyl ester blocked the dilation to intraluminal AngII, but neither affected constriction to topical AngII. Chromium mesoporphyrin, that inhibits heme oxygenase, did not affect responses to either topical or intravascular AngII. These data are consistent with the hypotheses that: (a) circulating AngII dilates pial arterioles via endothelial AT(1) receptor-derived relaxing factors, notably prostanoids and nitric oxide; (b) direct AT(1) receptor activation on the brain side of the blood-brain barrier by AngII causes AT(1) receptor-mediated constriction that can mask underlying AT(1) receptor-independent dilation when ACE is inhibited. Clinical manipulation of the renin-angiotensin system will have disparate actions on cerebral circulation depending on the functional integrity of the intima and ACE.
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Affiliation(s)
- Kenneth R Knecht
- Department of Pediatrics, University of Tennessee Center for the Health Sciences, Memphis, TN 38163, USA
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Ahnstedt H, Säveland H, Nilsson O, Edvinsson L. Human cerebrovascular contractile receptors are upregulated via a B-Raf/MEK/ERK-sensitive signaling pathway. BMC Neurosci 2011; 12:5. [PMID: 21223556 PMCID: PMC3023719 DOI: 10.1186/1471-2202-12-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Accepted: 01/11/2011] [Indexed: 11/11/2022] Open
Abstract
Background Cerebral ischemia results in a rapid increase in contractile cerebrovascular receptors, such as the 5-hydroxytryptamine type 1B (5-HT1B), angiotensin II type 1 (AT1), and endothelin type B (ETB) receptors, in the vessel walls within the ischemic region, which further impairs local blood flow and aggravates tissue damage. This receptor upregulation occurs via activation of the mitogen-activated protein kinase pathway. We therefore hypothesized an important role for B-Raf, the first signaling molecule in the pathway. To test our hypothesis, human cerebral arteries were incubated at 37°C for 48 h in the absence or presence of a B-Raf inhibitor: SB-386023 or SB-590885. Contractile properties were evaluated in a myograph and protein expression of the individual receptors and activated phosphorylated B-Raf (p-B-Raf) was evaluated immunohistochemically. Results 5-HT1B, AT1, and ETB receptor-mediated contractions were significantly reduced by application of SB-590885, and to a smaller extent by SB-386023. A marked reduction in AT1 receptor immunoreactivity was observed after treatment with SB-590885. Treatment with SB-590885 and SB-386023 diminished the culture-induced increase of p-B-Raf immunoreactivity. Conclusions B-Raf signaling has a key function in the altered expression of vascular contractile receptors observed after organ culture. Therefore, specific targeting of B-Raf might be a novel approach to reduce tissue damage after cerebral ischemia by preventing the previously observed upregulation of contractile receptors in smooth muscle cells.
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Affiliation(s)
- Hilda Ahnstedt
- Department of Clinical Sciences, Lund University, Sweden.
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Effects of suboptimal doses of the AT1 receptor blocker, telmisartan, with the angiotensin-converting enzyme inhibitor, ramipril, on cerebral arterioles in spontaneously hypertensive rat. J Hypertens 2010; 28:1566-73. [PMID: 20589978 DOI: 10.1097/hjh.0b013e328339f1f3] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Antihypertensive treatment with standard clinical doses of angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs) reverses cerebral arteriolar remodeling, thus restoring dilatation and the lower limit of cerebral blood flow (CBF) autoregulation (LL CBF AR). In humans, a combination of standard clinical doses of the two drugs does not produce greater protection against stroke than that obtained with single-drug treatments and increases the risk of side-effects. We hypothesized that a combination of suboptimal doses of the ARB, telmisartan (TEL) and of the ACEI, ramipril (RAM), could be a well tolerated and effective treatment of hypertension-induced remodeling of cerebral arterioles. DESIGN We studied the impact of 3-month oral treatment with TEL (0.5 or 0.8 mg/kg per day) or RAM (0.1 or 0.25mg/ kg per day) alone or in combination (TEL0.8 + RAM0.1 or TEL0.5 + RAM0.25) on the cerebral circulation of the spontaneously hypertensive rats (SHRs). Normotensive Wistar-Kyoto rats (WKYs) were taken as controls. METHODS Cerebral arteriolar pressure, CBF and internal diameter were measured via an open-skull preparation at baseline and during hypotension before and after deactivation (EDTA). RESULTS Combinations normalized cerebral arteriolar pressure, whereas drugs alone had no significant impact. TEL0.8 + RAM0.1 showed the greatest effect on arteriolar internal diameter (SHRs 42+/-16, WKYs 59+/-16microm, TEL0.5 + RAM0.25 50+/-6, TEL0.8 + RAM0.1 62+/-18, P<0.05) and normalized LL CBF AR (SHRs 77+/-28, WKYs 53+/-17 mmHg, TEL0.8 + RAM0.1 50+/-10, P<0.05). CONCLUSION The combination of suboptimal doses of TEL and RAM with an 8 : 1 ratio has the greatest effect on cerebral circulation and could represent well tolerated and efficient treatment of cerebral ischemia and stroke.
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Wu RS, Marx SO. The BK potassium channel in the vascular smooth muscle and kidney: α- and β-subunits. Kidney Int 2010; 78:963-74. [DOI: 10.1038/ki.2010.325] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Galzerano D, Capogrosso C, Di Michele S, Galzerano A, Paparello P, Lama D, Gaudio C. New standards in hypertension and cardiovascular risk management: focus on telmisartan. Vasc Health Risk Manag 2010; 6:113-33. [PMID: 20448797 PMCID: PMC2860444 DOI: 10.2147/vhrm.s7857] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Indexed: 12/21/2022] Open
Abstract
Blockade of the renin–angiotensin system is an important approach in managing high blood pressure, and has increasingly been shown to affect cardiovascular disease processes mediated by angiotensin II throughout the cardiovascular and renal continua. Telmisartan is an angiotensin II receptor blocker (ARB) displaying unique pharmacologic properties, including a longer half life than any other ARB, that result in large and sustained reductions of blood pressure. In patients with mild-to-moderate hypertension, telmisartan has proved superior to other antihypertensive agents (valsartan, losartan, ramipril, perindopril, and atenolol) in controlling blood pressure particularly towards the end of the dosing interval. There is also clinical evidence that telmisartan reduces left ventricular hypertrophy, reduces arterial stiffness and the recurrence of atrial fibrillation, and confers renoprotection. The ONgoing Telmisartan Alone and in combination with Ramipril Global Endpoint Trial (ONTARGET®) study has demonstrated that telmisartan has similar cardiovascular protective effects to ramipril in a large, high-risk patient population but was better tolerated. The powerful and sustained blood pressure control apparent in clinical trials, together with cardiovascular protection and tolerability demonstrated in ONTARGET® means that telmisartan may be a preferred option for patients with hypertension.
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Amburgey OA, Reeves SA, Bernstein IM, Cipolla MJ. Resistance artery adaptation to pregnancy counteracts the vasoconstricting influence of plasma from normal pregnant women. Reprod Sci 2009; 17:29-39. [PMID: 19767537 DOI: 10.1177/1933719109345288] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Using a rat model, we investigated the effects of circulating factors in pregnancy on cerebrovascular and systemic vascular function by comparing myogenic reactivity, tone, and endothelial vasodilator production of the posterior cerebral artery (PCA) and mesenteric artery (MA) of nonpregnant (NP) animals perfused with nonpregnant and pregnant human plasma. Arteries from late pregnant (LP) animals were then perfused similarly to evaluate a potential adaptive effect of pregnancy on vessel function. A 3-hour exposure to pregnant plasma caused increased myogenic reactivity and tone in vessels from NP animals and produced a decreased endothelium-derived hyperpolarizing factor response in NP PCAs, findings that were not seen with MAs. The increased reactivity and tone noted in NP vessels was abolished when pregnant plasma was perfused through LP arteries, suggesting these vessels adapt during pregnancy to the vasoconstricting influence of pregnant plasma.
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Affiliation(s)
- Odül A Amburgey
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of Vermont College of Medicine, Burlington, Vermont 05405, USA
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Salcedo A, Fernández N, García Villalón AL, Monge L, Narváez Sánchez R, Diéguez G. Role of angiotensin II in the response to endothelin-1 of goat cerebral arteries after ischemia-reperfusion. Vascul Pharmacol 2009; 50:160-5. [PMID: 19135174 DOI: 10.1016/j.vph.2008.12.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2008] [Revised: 10/30/2008] [Accepted: 12/05/2008] [Indexed: 10/21/2022]
Abstract
As angiotensin II may underlie the deleterious effects of some vascular diseases, we have examined the role of this peptide on the cerbrovascular endothelin-1 action after ischemia-reperfusion. In anesthetized goats, 1 hour-occlusion followed by 1 hour-reperfusion of the left middle cerebral artery (MCA) was induced, and then segments 3-mm in length from branches of the right MCA (control) and the left MCA (ischemic) were obtained for isometric tension recording. Endothelin-1 (10(-11)-10(-7) M) produced a contraction that was higher in ischemic than in control arteries, and in control but not in ischemic arteries this contraction was potentiated by angiotensin II (10(-7) M). Losartan (3 x 10(-6) M), antagonist of AT1 receptors, did not affect the response to endothelin-1 in control arteries, but reduced it both in ischemic arteries and angiotensin II-treated control arteries. PD123,319 (3 x 10(-6) M), antagonist of AT2 receptors, or the inhibitor of nitric oxide synthesis L-NAME (10(-4) M) did not alter the arterial effects of endothelin-1. Therefore, angiotensin II may potentiate the constriction to endothelin-1 in normal cerebral arteries by activating AT1 receptors. The observed cerebrovascular increased response to endothelin-1 after ischemia-reperfusion might be related in part to activation of AT1 receptors under this condition.
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Affiliation(s)
- Adely Salcedo
- Departamento de Fisiología, Facultad de Medicina, Universidad Autónoma, Arzobispo Morcillo, 4, 28029 Madrid, Spain
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De Silva TM, Broughton BR, Drummond GR, Sobey CG, Miller AA. Gender Influences Cerebral Vascular Responses to Angiotensin II Through Nox2-Derived Reactive Oxygen Species. Stroke 2009; 40:1091-7. [DOI: 10.1161/strokeaha.108.531707] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- T. Michael De Silva
- From the Department of Pharmacology, Monash University, Clayton, Melbourne, Victoria, Australia
| | - Brad R.S. Broughton
- From the Department of Pharmacology, Monash University, Clayton, Melbourne, Victoria, Australia
| | - Grant R. Drummond
- From the Department of Pharmacology, Monash University, Clayton, Melbourne, Victoria, Australia
| | - Christopher G. Sobey
- From the Department of Pharmacology, Monash University, Clayton, Melbourne, Victoria, Australia
| | - Alyson A. Miller
- From the Department of Pharmacology, Monash University, Clayton, Melbourne, Victoria, Australia
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Jones ES, Vinh A, McCarthy CA, Gaspari TA, Widdop RE. AT2 receptors: functional relevance in cardiovascular disease. Pharmacol Ther 2008; 120:292-316. [PMID: 18804122 PMCID: PMC7112668 DOI: 10.1016/j.pharmthera.2008.08.009] [Citation(s) in RCA: 199] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2008] [Accepted: 08/07/2008] [Indexed: 12/24/2022]
Abstract
The renin angiotensin system (RAS) is intricately involved in normal cardiovascular homeostasis. Excessive stimulation by the octapeptide angiotensin II contributes to a range of cardiovascular pathologies and diseases via angiotensin type 1 receptor (AT1R) activation. On the other hand, tElsevier Inc.he angiotensin type 2 receptor (AT2R) is thought to counter-regulate AT1R function. In this review, we describe the enhanced expression and function of AT2R in various cardiovascular disease settings. In addition, we illustrate that the RAS consists of a family of angiotensin peptides that exert cardiovascular effects that are often distinct from those of Ang II. During cardiovascular disease, there is likely to be an increased functional importance of AT2R, stimulated by Ang II, or even shorter angiotensin peptide fragments, to limit AT1R-mediated overactivity and cardiovascular pathologies.
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Key Words
- angiotensin ii
- at2 receptor
- at1 receptor
- cardiovascular disease
- ace, angiotensin converting enzyme
- ace2, angiotensin converting enzyme 2
- ang ii, angiotensin ii
- ang iii, angiotensin iii
- ang iv, angiotensin iv
- ang (1–7), angiotensin (1–7)
- atbp50, at2r-binding protein of 50 kda
- atip-1, at2 receptor interacting protein-1
- at1r, angiotensin ii type 1 receptor
- at2r, angiotensin ii type 2 receptor
- at4r, angiotensin ii type 4 receptor
- bk, bradykinin
- bp, blood pressure
- cgmp, cyclic guanine 3′,5′-monophosphate
- ecm, extracellular matrix
- enos, endothelial nitric oxide synthase
- erk-1/2, extracellular-regulated kinases-1,2
- irap, insulin-regulated aminopeptidase
- l-name, ng-nitro-l arginine methyl ester
- lvh, left ventricular hypertrophy
- mapk, mitogen-activated protein kinase
- mcp-1, monocyte chemoattractant protein-1
- mi, myocardial infarction
- mmp, matrix metalloproteinase
- mrna, messenger ribonucleic acid
- nf-κβ, nuclear transcription factor-κβ
- no, nitric oxide
- o2−, superoxide
- pc12w, rat pheochromocytoma cell line
- ras, renin angiotensin system
- ros, reactive oxygen species
- shr, spontaneously hypertensive rat
- timp-1, tissue inhibitor of metalloproteinase-1
- tnfα, tumour-necrosis factor α
- vsmc, vascular smooth muscle cell
- wky, wistar-kyoto rat
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Affiliation(s)
- Emma S Jones
- Department of Pharmacology, Monash University, Clayton, Victoria 3800, Australia
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Edvinsson L. Cerebrovascular Angiotensin AT1 Receptor Regulation in Cerebral Ischemia. Trends Cardiovasc Med 2008; 18:98-103. [DOI: 10.1016/j.tcm.2008.01.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2007] [Revised: 01/20/2008] [Accepted: 01/25/2008] [Indexed: 10/22/2022]
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Stenman E, Jamali R, Henriksson M, Maddahi A, Edvinsson L. Cooperative effect of angiotensin AT1 and endothelin ETA receptor antagonism limits the brain damage after ischemic stroke in rat. Eur J Pharmacol 2007; 570:142-8. [PMID: 17597600 DOI: 10.1016/j.ejphar.2007.05.049] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2007] [Revised: 05/14/2007] [Accepted: 05/15/2007] [Indexed: 11/15/2022]
Abstract
Cerebral ischemia results in enhanced expression of smooth muscle cell endothelin and angiotensin receptors in cerebral arteries. We hypothesise that this phenomenon may be detrimental and that acute treatment with a combined non-hypotensive dose of the angiotensin AT(1) receptor inhibitor candesartan and the endothelin ET(A) receptor antagonist ZD1611 reduces the infarct in experimental ischemic stroke. Transient middle cerebral artery occlusion was induced in male Wistar rats by the intraluminal filament technique for 2 h followed by recirculation. The animals received systemic candesartan (0.05 mg/kg/day), ZD1611 (0.15 mg/kg/day), both combined or vehicle with start immediately after the occlusion. After 48 h the rats were sacrificed, the brains sliced and stained with 1% 2, 3, 5-triphenyltetrazolium chloride (TTC) and the volume of ischemic damage determined. The middle cerebral arteries were harvested for immunocytochemical studies of angiotensin AT(1) and endothelin ET(A) receptor expression. Candesartan or ZD1611 did alone not significantly decrease the brain damage or improve neurological scores as compared to vehicle controls. The combined inhibition of angiotensin AT(1) and endothelin ET(A) receptors however decreased the brain damage and improved the neurological scores (both P<0.05). The treatment did not change resting mean arterial blood pressure. In addition, there was an upregulation of angiotensin AT(1) receptors in the ischemic middle cerebral artery smooth muscle cells, which was normalised by the combined treatment. In conclusion, the present study shows that combined inhibition of angiotensin AT(1) and endothelin ET(A) receptors reduces the brain damage and improves the neurological outcome after ischemic stroke in rat.
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Affiliation(s)
- Emelie Stenman
- Institution of Clinical Sciences Lund, Department of Experimental Vascular Research, Lund University, BMC A13, 22184 Lund, Sweden
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Atkinson J, Dupuis F, Chillon JM. [Renin-angiotensin-aldosterone system: an old system offering new drug targets for the cerebral circulation]. ANNALES PHARMACEUTIQUES FRANÇAISES 2007; 65:195-202. [PMID: 17489076 DOI: 10.1016/s0003-4509(07)90036-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
In a rat model of human essential hypertension (SHR), the chronic increase in cerebral arteriolar blood pressure is accompanied by remodelling with wall hypertrophy and a fall in diameter. The latter produces an increase in cerebrovascular resistance which maintains cerebral blood flow autoregulation at high systemic blood pressure levels, but accentuates hypoperfusion at low arterial pressures such as those observed during and following cerebral ischemia. Using ACE inhibitors and AT1 blockers we have shown that the normalisation of wall thickness is pressure-dependent but that the normalisation of arteriolar diameter relates to a pressure-independent mechanism involving aldosterone. This raises the possibility of new drug targets for arteriolar remodelling involving intracellular sodium-dependent modulation of protein metabolism.
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Affiliation(s)
- J Atkinson
- Laboratoire de Pharmacologie, Faculté de pharmacie, Université Henri Poincaré, Nancy 1, 5 rue Albert Lebrun, F 54000 Nancy
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Zhang R, Witkowski S, Fu Q, Claassen JAHR, Levine BD. Cerebral Hemodynamics After Short- and Long-Term Reduction in Blood Pressure in Mild and Moderate Hypertension. Hypertension 2007; 49:1149-55. [PMID: 17353511 DOI: 10.1161/hypertensionaha.106.084939] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study tested the hypothesis that acute reduction in blood pressure (BP) at the initial stage of antihypertensive therapy compromises brain perfusion and dynamic cerebral autoregulation in patients with hypertension. Cerebral blood flow velocity and BP were measured in patients with mild and moderate hypertension and in healthy volunteers at baseline upon reduction of BP within 1 to 2 weeks of administration of losartan/hydrochlorothiazide and after 3 to 4 months of treatment. The transfer function between beat-to-beat changes in BP and cerebral blood flow velocity was estimated to assess dynamic autoregulation. After 1 to 2 weeks of treatment, BP was reduced in mild (143±7/88±4 versus 126±12/77±6 mm Hg) and moderate hypertension (163±11/101±9 versus 134±17/84±9 mm Hg;
P
<0.05). These reductions in BP were well maintained over the 3 to 4 month period. Cerebral blood flow velocity did not change, whereas cerebrovascular resistance index was reduced by 17% (
P
<0.05) after reduction in BP. Responses of cerebral blood flow velocity to head-up tilt remained unchanged. Baseline transfer function gain at the low frequencies (0.07 to 0.20 Hz) was reduced in moderate hypertension, consistent with cerebral vasoconstriction and/or enhanced dynamic autoregulation. However, this reduced transfer function gain was restored to the level of control subjects after reduction in BP. These findings, contrary to our hypothesis, demonstrate that there is a rapid adaptation of the cerebral vasculature to protect the brain from hypoperfusion even at the initial stage of antihypertensive therapy in patients with mild and moderate hypertension.
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Affiliation(s)
- Rong Zhang
- Institute for Exercise and Environmental Medicine, Presbyterian Hospital of Dallas, University of Texas Southwestern Medical Center, TX 75231, USA.
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