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van Rijssel AE, Stins BC, Beishon LC, Sanders ML, Quinn TJ, Claassen JA, de Heus RA. Effect of Antihypertensive Treatment on Cerebral Blood Flow in Older Adults: a Systematic Review and Meta-Analysis. Hypertension 2022; 79:1067-1078. [PMID: 35193363 PMCID: PMC8997667 DOI: 10.1161/hypertensionaha.121.18255] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Accepted: 01/21/2022] [Indexed: 11/16/2022]
Abstract
BACKGROUND In older age, the benefits of antihypertensive treatment (AHT) become less evident, with greater associated risk. Of particular concern is compromising cerebral blood flow (CBF), especially in those with cognitive impairment. METHODS We created a synthesis of the published evidence by searching multiple electronic databases from 1970 to May 2021. Included studies had participants with mean age ≥50 years, hypertension or cognitive impairment, and assessed CBF before and after initiating AHT. Two authors independently determined eligibility and extracted data. Study quality was assessed using The Risk of Bias in Nonrandomized Studies of Interventions tool. We summarized study characteristics (qualitative synthesis) and performed random-effects meta-analyses (quantitative synthesis). RESULTS Thirty-two studies (total n=1306) were included, of which 23 were eligible for meta-analysis. In line with the qualitative synthesis, the meta-analysis indicated no effect of AHT initiation on CBF (standardized mean difference, 0.08 [95% CI, -0.07 to 0.22]; P=0.31, I2=42%). This was consistent across subgroups of acute versus chronic AHT, drug class, study design, and CBF measurement. Subgroups by age demonstrated an increase in CBF after AHT in those aged >70 years (standardized mean difference, 4.15 [95% CI, 0.16-8.15]; P=0.04, I2=42%), but not in those aged 50 to 65 and 65 to 70 years (standardized mean difference, 0.18 [95% CI,-2.02 to 2.38]; P=0.87, I2=49%; standardized mean difference, 1.22 [95% CI, -0.45 to 2.88]; P=0.15, I2=68%). Overall, risk of bias was moderate-to-high and quality of evidence (Grading of Recommendations Assessment, Development and Evaluation) was very low, reflecting the observational nature of the data. CONCLUSIONS Accepting the observed limitations, current evidence does not suggest a harmful effect of AHT on CBF. Concerns over CBF should not preclude treatment of hypertension.
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Affiliation(s)
- Anniek E. van Rijssel
- Radboud university medical center, Donders Institute for Brain Cognition and Behaviour, Department of Geriatric Medicine, Radboudumc Alzheimer Center, Nijmegen, the Netherlands (A.E.v.R., B.C.S., M.L.S., J.A.H.R.C., R.A.A.d.H.)
| | - Bram C. Stins
- Radboud university medical center, Donders Institute for Brain Cognition and Behaviour, Department of Geriatric Medicine, Radboudumc Alzheimer Center, Nijmegen, the Netherlands (A.E.v.R., B.C.S., M.L.S., J.A.H.R.C., R.A.A.d.H.)
| | - Lucy C. Beishon
- Department of Cardiovascular Sciences, University of Leicester, United Kingdom (L.C.B.)
| | - Marit L. Sanders
- Radboud university medical center, Donders Institute for Brain Cognition and Behaviour, Department of Geriatric Medicine, Radboudumc Alzheimer Center, Nijmegen, the Netherlands (A.E.v.R., B.C.S., M.L.S., J.A.H.R.C., R.A.A.d.H.)
| | - Terence J. Quinn
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (T.J.Q.)
| | - Jurgen A.H.R. Claassen
- Radboud university medical center, Donders Institute for Brain Cognition and Behaviour, Department of Geriatric Medicine, Radboudumc Alzheimer Center, Nijmegen, the Netherlands (A.E.v.R., B.C.S., M.L.S., J.A.H.R.C., R.A.A.d.H.)
| | - Rianne A.A. de Heus
- Radboud university medical center, Donders Institute for Brain Cognition and Behaviour, Department of Geriatric Medicine, Radboudumc Alzheimer Center, Nijmegen, the Netherlands (A.E.v.R., B.C.S., M.L.S., J.A.H.R.C., R.A.A.d.H.)
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Cosarderelioglu C, Nidadavolu LS, George CJ, Oh ES, Bennett DA, Walston JD, Abadir PM. Brain Renin-Angiotensin System at the Intersect of Physical and Cognitive Frailty. Front Neurosci 2020; 14:586314. [PMID: 33117127 PMCID: PMC7561440 DOI: 10.3389/fnins.2020.586314] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 08/25/2020] [Indexed: 12/15/2022] Open
Abstract
The renin–angiotensin system (RAS) was initially considered to be part of the endocrine system regulating water and electrolyte balance, systemic vascular resistance, blood pressure, and cardiovascular homeostasis. It was later discovered that intracrine and local forms of RAS exist in the brain apart from the endocrine RAS. This brain-specific RAS plays essential roles in brain homeostasis by acting mainly through four angiotensin receptor subtypes; AT1R, AT2R, MasR, and AT4R. These receptors have opposing effects; AT1R promotes vasoconstriction, proliferation, inflammation, and oxidative stress while AT2R and MasR counteract the effects of AT1R. AT4R is critical for dopamine and acetylcholine release and mediates learning and memory consolidation. Consequently, aging-associated dysregulation of the angiotensin receptor subtypes may lead to adverse clinical outcomes such as Alzheimer’s disease and frailty via excessive oxidative stress, neuroinflammation, endothelial dysfunction, microglial polarization, and alterations in neurotransmitter secretion. In this article, we review the brain RAS from this standpoint. After discussing the functions of individual brain RAS components and their intracellular and intracranial locations, we focus on the relationships among brain RAS, aging, frailty, and specific neurodegenerative diseases, such as Alzheimer’s disease, Parkinson’s disease, and vascular cognitive impairment, through oxidative stress, neuroinflammation, and vascular dysfunction. Finally, we discuss the effects of RAS-modulating drugs on the brain RAS and their use in novel treatment approaches.
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Affiliation(s)
- Caglar Cosarderelioglu
- Division of Geriatrics, Department of Internal Medicine, Ankara University School of Medicine, Ankara, Turkey.,Division of Geriatric Medicine and Gerontology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Lolita S Nidadavolu
- Division of Geriatric Medicine and Gerontology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Claudene J George
- Division of Geriatrics, Department of Medicine, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY, United States
| | - Esther S Oh
- Division of Geriatric Medicine and Gerontology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - David A Bennett
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, United States
| | - Jeremy D Walston
- Division of Geriatric Medicine and Gerontology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Peter M Abadir
- Division of Geriatric Medicine and Gerontology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
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Kehoe PG. The Coming of Age of the Angiotensin Hypothesis in Alzheimer's Disease: Progress Toward Disease Prevention and Treatment? J Alzheimers Dis 2019; 62:1443-1466. [PMID: 29562545 PMCID: PMC5870007 DOI: 10.3233/jad-171119] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
There is wide recognition of a complex association between midlife hypertension and cardiovascular disease and later development of Alzheimer’s disease (AD) and cognitive impairment. While significant progress has been made in reducing rates of mortality and morbidity due to cardiovascular disease over the last thirty years, progress towards effective treatments for AD has been slower. Despite the known association between hypertension and dementia, research into each disease has largely been undertaken in parallel and independently. Yet over the last decade and a half, the emergence of converging findings from pre-clinical and clinical research has shown how the renin angiotensin system (RAS), which is very important in blood pressure regulation and cardiovascular disease, warrants careful consideration in the pathogenesis of AD. Numerous components of the RAS have now been found to be altered in AD such that the multifunctional and potent vasoconstrictor angiotensin II, and similarly acting angiotensin III, are greatly altered at the expense of other RAS signaling peptides considered to contribute to neuronal and cognitive function. Collectively these changes may contribute to many of the neuropathological hallmarks of AD, as well as observed progressive deficiencies in cognitive function, while also linking elements of a number of the proposed hypotheses for the cause of AD. This review discusses the emergence of the RAS and its likely importance in AD, not only because of the multiple facets of its involvement, but also perhaps fortuitously because of the ready availability of numerous RAS-acting drugs, that could be repurposed as interventions in AD.
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Affiliation(s)
- Patrick Gavin Kehoe
- Dementia Research Group, Translational Health Sciences, Bristol Medical School, University of Bristol, Southmead Hospital, Bristol, UK
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Abstract
This review describes the features of Alzheimer's disease and discusses the evidence that antihypertensive therapies may be beneficial in its treatment and prevention. Drugs acting via the renin-angiotensin system are considered and it is suggested that these drugs may produce their effects via mechanisms other than by their antihypertensive actions. Using evidence from animal studies, the role of angiotensin as a neurotransmitter and its involvement in the control of normal cognitive function is described. Studies of angiotensin and human cognition are reviewed along with studies investigating the possible link between disorders of the system, either inherited or acquired, and the symptoms of Alzheimer's disease. The therapeutic potential of screening for markers of renin-angiotensin abnormality for the prediction of Alzheimer's disease is considered, as is the potential use of agents known to influence the renin-angiotensin system in the treatment or prevention of the disease.
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Affiliation(s)
- Paul R Gard
- School of Pharmacy & Biomolecular Sciences, University of Brighton, Brighton, BN2 4GJ, UK.
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Solfrizzi V, Scafato E, Frisardi V, Seripa D, Logroscino G, Kehoe PG, Imbimbo BP, Baldereschi M, Crepaldi G, Di Carlo A, Galluzzo L, Gandin C, Inzitari D, Maggi S, Pilotto A, Panza F. Angiotensin-converting enzyme inhibitors and incidence of mild cognitive impairment. The Italian Longitudinal Study on Aging. AGE (DORDRECHT, NETHERLANDS) 2013; 35:441-53. [PMID: 22203459 PMCID: PMC3592955 DOI: 10.1007/s11357-011-9360-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Accepted: 12/05/2011] [Indexed: 05/14/2023]
Abstract
Midlife elevated blood pressure and hypertension contribute to the development of Alzheimer's disease (AD) and overall dementia. We sought to estimate whether angiotensin-converting enzyme inhibitors (ACE-Is) reduced the risk of developing mild cognitive impairment (MCI) in cognitively normal individuals. In the Italian Longitudinal Study on Aging, we evaluated 1,445 cognitively normal individuals treated for hypertension but without congestive heart failure from a population-based sample from eight Italian municipalities with a 3.5-year follow-up. MCI was diagnosed with current clinical criteria. Dementia, AD, and vascular dementia were diagnosed based on DSM-IIIR criteria, NINCDS-ADRDA criteria, and ICD-10 codes. Among 873 hypertension-treated cognitively normal subjects, there was no significant association between continuous exposure to all ACE-Is and risk of incident MCI compared with other antihypertensive drugs [hazard ratio (HR), 0.45, 95% confidence interval (CI), 0.16-1.28]. Captopril exposure alone did not significantly modify the risk of incident MCI (HR, 1.80, 95% CI, 0.39-8.37). However, the enalapril sub-group alone (HR, 0.17, 95% CI, 0.04 -0.84) or combined with the lisinopril sub-group (HR, 0.27, 95% CI, 0.08-0.96), another ACE-I structurally related to enalapril and with similar potency, were associated with a reduced risk of incident MCI. Study duration exposure to ACE-Is as a "class" was not associated with incident MCI in older hypertensive adults. However, within-class differences linked to different chemical structures and/or drug potencies may exist, with a possible effect of the enalapril and lisinopril sub-groups in reducing the risk of incident MCI.
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Affiliation(s)
- Vincenzo Solfrizzi
- />Department of Geriatrics, Center for Aging Brain, Memory Unit, University of Bari, Policlinico, Piazza Giulio Cesare, 11, 70124 Bari, Italy
| | - Emanuele Scafato
- />Population Health and Health Determinants Unit, National Centre for Epidemiology, Surveillance and Health Promotion (CNESPS), Istituto Superiore di Sanità (ISS), Roma, Italy
| | - Vincenza Frisardi
- />Department of Geriatrics, Center for Aging Brain, Memory Unit, University of Bari, Policlinico, Piazza Giulio Cesare, 11, 70124 Bari, Italy
| | - Davide Seripa
- />Geriatric Unit & Gerontology-Geriatrics Research Laboratory, Department of Medical Sciences, IRCCS Casa Sollievo della Sofferenza, Viale Cappuccini 1, 71013 San Giovanni Rotondo, Foggia Italy
| | - Giancarlo Logroscino
- />Department of Neurological and Psychiatric Sciences, University of Bari, Bari, Italy
| | - Patrick G. Kehoe
- />Dementia Research Group, Institute of Clinical Neurosciences, The John James Building, Frenchay Hospital, University of Bristol, Bristol, UK
| | - Bruno P. Imbimbo
- />Research and Development Department, Chiesi Farmaceutici, Parma, Italy
| | - Marzia Baldereschi
- />Institute of Neuroscience, Italian National Research Council (CNR), Firenze, Italy
| | - Gaetano Crepaldi
- />Aging Section, Italian National Research Council (CNR), Padova, Italy
| | - Antonio Di Carlo
- />Institute of Neuroscience, Italian National Research Council (CNR), Firenze, Italy
| | - Lucia Galluzzo
- />Population Health and Health Determinants Unit, National Centre for Epidemiology, Surveillance and Health Promotion (CNESPS), Istituto Superiore di Sanità (ISS), Roma, Italy
| | - Claudia Gandin
- />Population Health and Health Determinants Unit, National Centre for Epidemiology, Surveillance and Health Promotion (CNESPS), Istituto Superiore di Sanità (ISS), Roma, Italy
| | - Domenico Inzitari
- />Department of Neurological and Psychiatric Sciences, University of Firenze, Firenze, Italy
| | - Stefania Maggi
- />Aging Section, Italian National Research Council (CNR), Padova, Italy
| | - Alberto Pilotto
- />Geriatric Unit & Gerontology-Geriatrics Research Laboratory, Department of Medical Sciences, IRCCS Casa Sollievo della Sofferenza, Viale Cappuccini 1, 71013 San Giovanni Rotondo, Foggia Italy
| | - Francesco Panza
- />Geriatric Unit & Gerontology-Geriatrics Research Laboratory, Department of Medical Sciences, IRCCS Casa Sollievo della Sofferenza, Viale Cappuccini 1, 71013 San Giovanni Rotondo, Foggia Italy
| | - for the Italian Longitudinal Study on Aging Working Group
- />Department of Geriatrics, Center for Aging Brain, Memory Unit, University of Bari, Policlinico, Piazza Giulio Cesare, 11, 70124 Bari, Italy
- />Population Health and Health Determinants Unit, National Centre for Epidemiology, Surveillance and Health Promotion (CNESPS), Istituto Superiore di Sanità (ISS), Roma, Italy
- />Geriatric Unit & Gerontology-Geriatrics Research Laboratory, Department of Medical Sciences, IRCCS Casa Sollievo della Sofferenza, Viale Cappuccini 1, 71013 San Giovanni Rotondo, Foggia Italy
- />Department of Neurological and Psychiatric Sciences, University of Bari, Bari, Italy
- />Dementia Research Group, Institute of Clinical Neurosciences, The John James Building, Frenchay Hospital, University of Bristol, Bristol, UK
- />Research and Development Department, Chiesi Farmaceutici, Parma, Italy
- />Institute of Neuroscience, Italian National Research Council (CNR), Firenze, Italy
- />Aging Section, Italian National Research Council (CNR), Padova, Italy
- />Department of Neurological and Psychiatric Sciences, University of Firenze, Firenze, Italy
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Kugaevskaya EV. Angiotensin converting enzyme and Alzheimer’s disease. BIOCHEMISTRY MOSCOW-SUPPLEMENT SERIES B-BIOMEDICAL CHEMISTRY 2012. [DOI: 10.1134/s199075081201009x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Kehoe PG, Miners S, Love S. Angiotensins in Alzheimer's disease - friend or foe? Trends Neurosci 2009; 32:619-28. [PMID: 19796831 DOI: 10.1016/j.tins.2009.07.006] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2009] [Revised: 07/22/2009] [Accepted: 07/28/2009] [Indexed: 11/28/2022]
Abstract
The renin-angiotensin system (RAS) is an important regulator of blood pressure. Observational and experimental studies suggest that alterations in blood pressure and components of the brain RAS contribute to the development and progression of Alzheimer's disease (AD), resulting in changes that can lead or contribute to cognitive decline. The complexity of the RAS and diversity of its interactions with neurological processes have recently become apparent but large gaps in our understanding still remain. Modulation of activity of components of the brain RAS offers substantial opportunities for the treatment and prevention of dementia, including AD. This paper reviews molecular, genetic, experimental and clinical data as well as the therapeutic opportunities that relate to the involvement of the RAS in AD.
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Affiliation(s)
- Patrick G Kehoe
- Dementia Research Group, Institute of Clinical Neurosciences, Department of Clinical Science at North Bristol, University of Bristol, Frenchay Hospital, Bristol BS16 1LE, UK.
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Hajjar I, Keown M, Frost B. Antihypertensive agents for aging patients who are at risk for cognitive dysfunction. Curr Hypertens Rep 2005; 7:466-73. [PMID: 16386204 DOI: 10.1007/s11906-005-0043-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Observational and experimental data continue to accumulate about the impact of blood pressure (BP) and antihypertensive agents on cognitive function. Current evidence suggests that there is a U-shaped association between BP earlier in life and poor cognitive function and clinical dementia, including Alzheimer's disease. This association has been identified more consistently in longitudinal surveys due to the fact that BP declines when cognitive symptoms start. Lowering BP provides protection against this complication of high BP. This effect is present in the cognitively intact and in those with dementia. Antihypertensives that cross the blood brain barrier and affect the renin-angiotensin-aldosterone system (such as perindopril or losartan) or brain calcium metabolism (nitrendipine) provide additional protection beyond BP control against cognitive decline. These drugs may be preferred in such clinical situations.
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Affiliation(s)
- Ihab Hajjar
- Department of Internal Medicine, Palmetto Health Richland/University of South Carolina, 9 Medical Park Drive, Suite 230, Columbia, SC 29203, USA.
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Gard PR. Angiotensin as a target for the treatment of Alzheimer’s disease, anxiety and depression. Expert Opin Ther Targets 2005; 8:7-14. [PMID: 14996614 DOI: 10.1517/14728222.8.1.7] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The brain renin-angiotensin system (RAS), which is comprised of a variety of peptides including angiotensin II, angiotensin III and angiotensin IV acting on AT<inf>1</inf>, AT<inf>2</inf> and AT<inf>4</inf> receptors, is important in cognition and anxiety. Perturbation of the RAS improves basal cognition and reverses age-, scopolamine-, ethanol- and diabetes-induced deficits. In studies of dementias and Alzheimer's disease (AD), some studies have shown that antihypertensive drugs, including angiotensin-converting enzyme inhibitors, have some moderate effects on cognitive decline, but that the angiotensin receptor antagonist losartan has a significantly beneficial effect. These findings suggest that angiotensin receptor ligands may have potential in the prevention or even reversal of vascular dementias and AD. With respect to depression and anxiety, there is similar experimental evidence from animal models that drugs acting on the RAS may be antidepressant or anxiolytic, but insufficient clinical data exist. Such effects, if proven, could promote the use of such agents in the treatment of hypertension coexisting with depression or anxiety.
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Affiliation(s)
- Paul R Gard
- University of Brighton, School of Pharmacy and Biomolecular Sciences, UK.
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Cutler NR, Sramek JJ, Luna A, Mena I, Brass EP, Kurtz NM, Brennan JJ. Effect of the ACE inhibitor ceronapril on cerebral blood flow in hypertensive patients. Ann Pharmacother 1996; 30:578-82. [PMID: 8792940 DOI: 10.1177/106002809603000601] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
OBJECTIVE To assess the effect of the angiotensin-converting enzyme inhibitor ceronapril on cerebral blood flow (CBF) in patients with moderate hypertension. DESIGN Patients received chlorthalidone 25 mg for 4 weeks, and if diastolic blood pressure remained in the range of 100-115 mm Hg, they were given titrated doses of ceronapril (10-40 mg/d based on blood pressure response) in addition to chlorthalidone for 9 weeks. SETTING Outpatient research clinic. SUBJECTS Eligible patients had moderate essential hypertension (diastolic blood pressure 100-115 mm Hg) assessed when the patients were receiving no medications. Thirteen patients were entered into the study; 1 withdrew for reasons unrelated to the study drug. Twelve patients (11 men, 1 woman; mean age 52 y) completed the study. INTERVENTION Ceronapril, given with chlorthalidone. MAIN OUTCOME MEASURES CBF measurements were taken at the start and end of ceronapril therapy using intravenous 133Xe; blood pressures were determined weekly. RESULTS Mean arterial blood pressure decreased from 130 +/- 4 to 120 +/- 7 mm Hg after 4 weeks of chlorthalidone administration, and fell further to 108 +/- 8 mm Hg after an additional 9 weeks of combined chlorthalidone-ceronapril therapy (p < 0.05). CBF fell from 44 +/- 15 to 34 +/- 5 mL/min/100 g during the 9 weeks of combined therapy (p = 0.05). No adverse effects consistent with decreased CBF were observed. The decrease in CBF was not linearly correlated with the change in systemic blood pressure, but was strongly correlated (r = -0.937; p < 0.001) with the initial CBF. CONCLUSIONS The decrease in mean arterial blood pressure was not associated with a decrease in CBF. Patients with high CBF may be predisposed to a decrease in CBF when treated with ceronapril and chlorthalidone.
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Affiliation(s)
- N R Cutler
- Harbor-UCLA Medical Center, Torrance, USA
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Ge J, Barnes NM. Alterations in angiotensin AT1 and AT2 receptor subtype levels in brain regions from patients with neurodegenerative disorders. Eur J Pharmacol 1996; 297:299-306. [PMID: 8666063 DOI: 10.1016/0014-2999(95)00762-8] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The present studies assessed the levels of [125I][Sar1,ILE8]angiotensin II-labelled angiotensin AT1 and AT2 receptor recognition sites in homogenates of various brain areas (including caudate nucleus, putamen, substantia nigra, hippocampus, frontal cortex, temporal cortex and cerebellum) from patients with clinically diagnosed Parkinson's disease, Huntington's disease and Alzheimer's disease and those from age-, sex- and post-mortem delay-matched neurologically and psychiatrically normal patients. Radiolabelled angiotensin AT1 receptor recognition site levels were significantly decreased by approximately 70%, 70% and 90% in the caudate nucleus, putamen and substantia nigra, respectively, from patients with Parkinson's disease relative to matched controls. Furthermore, radiolabelled angiotensin AT2 receptor levels were decreased by some 60% in the caudate nucleus of patients with Parkinson's disease relative to control patients. In brain tissue homogenates from patients with Huntington's disease, the angiotensin AT1 receptor recognition site levels were decreased by approximately 30% in putamen relative to the control patients whilst angiotensin AT2 receptor levels were increased by some 90% in the caudate nucleus relative to the control patients. In brain tissue homogenates from patients with Alzheimer disease, the angiotensin AT2 receptor recognition site levels were significantly increased by approximately 200% in the temporal cortex relative to the control patients. The present results indicate that the reduction of angiotensin AT1 and/or AT2 receptor recognition site levels in the caudate nucleus, putamen and substantia nigra correlates with the principal neuropathology associated with Parkinson's disease and as such indicates that at least a significant population of angiotensin AT1 and AT2 receptors are located on the human dopaminergic nigrostriatal pathway. In addition, the marked increase in the levels of angiotensin AT2 receptor recognition sites in temporal cortex from patients with Alzheimer's disease correlates with some other markers associated with the renin-angiotensin system previously investigated in tissue from patients with this neurological disease.
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Affiliation(s)
- J Ge
- Department of Pharmacology, Medical School, University of Birmingham, Edgbaston, UK
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Chapter 21. Alzheimer's Disease: Current Therapeutic Approaches. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 1993. [DOI: 10.1016/s0065-7743(08)60891-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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