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Longarzo ML, Vázquez RF, Bellini MJ, Zamora RA, Redondo-Morata L, Giannotti MI, Oliveira Jr ON, Fanani ML, Maté SM. Understanding the effects of omega-3 fatty acid supplementation on the physical properties of brain lipid membranes. iScience 2024; 27:110362. [PMID: 39071883 PMCID: PMC11277689 DOI: 10.1016/j.isci.2024.110362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 03/24/2024] [Accepted: 06/21/2024] [Indexed: 07/30/2024] Open
Abstract
A deficiency in omega-3 fatty acids (ω3 FAs) in the brain has been correlated with cognitive impairment, learning deficiencies, and behavioral changes. In this study, we provided ω3 FAs as a supplement to spontaneously hypertensive rats (SHR+ ω3). Our focus was on examining the impact of dietary supplementation on the physicochemical properties of the brain-cell membranes. Significant increases in ω3 levels in the cerebral cortex of SHR+ ω3 were observed, leading to alterations in brain lipid membranes molecular packing, elasticity, and lipid miscibility, resulting in an augmented phase disparity. Results from synthetic lipid mixtures confirmed the disordering effect introduced by ω3 lipids, showing its consequences on the hydration levels of the monolayers and the organization of the membrane domains. These findings suggest that dietary ω3 FAs influence the organization of brain membranes, providing insight into a potential mechanism for the broad effects of dietary fat on brain health and disease.
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Affiliation(s)
- María L. Longarzo
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), CCT- La Plata, CONICET, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, 60 y 120, (1900), La Plata, Argentina
| | - Romina F. Vázquez
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), CCT- La Plata, CONICET, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, 60 y 120, (1900), La Plata, Argentina
| | - María J. Bellini
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), CCT- La Plata, CONICET, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, 60 y 120, (1900), La Plata, Argentina
| | - Ricardo A. Zamora
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
- Instituto de Investigación Interdisciplinaria (I³), Vicerrectoría Académica, and Centro de Bioinformática, Simulación y Modelado (CBSM), Facultad de Ingeniería, Universidad de Talca, Campus Lircay, Talca 3460000, Chile
| | - Lorena Redondo-Morata
- Université de Lille, CNRS, INSERM, CHU Lille, Institut Pasteur de Lille, U1019-UMR9017, CIIL—Center for Infection and Immunity of Lille, F-59000 Lille, France
| | - Marina I. Giannotti
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
- CIBER-BBN, ISCIII, 08028 Barcelona, Spain
- Department of Materials Science and Physical Chemistry, University of Barcelona, 08028 Barcelona, Spain
| | - Osvaldo N. Oliveira Jr
- São Carlos Institute of Physics (IFSC-USP), University of São Paulo, 13566-590 São Carlos, São Paulo, Brazil
| | - María L. Fanani
- Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), CONICET, Cordoba, Argentina
- Departamento de Química Biológica Raquel Caputto, Facultad de Cs. Químicas, Universidad Nacional de Córdoba. Haya de la Torre y Medina Allende, Ciudad Universitaria, Córdoba, Argentina
| | - Sabina M. Maté
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), CCT- La Plata, CONICET, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, 60 y 120, (1900), La Plata, Argentina
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Tarawneh R. Microvascular Contributions to Alzheimer Disease Pathogenesis: Is Alzheimer Disease Primarily an Endotheliopathy? Biomolecules 2023; 13:830. [PMID: 37238700 PMCID: PMC10216678 DOI: 10.3390/biom13050830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 05/07/2023] [Accepted: 05/08/2023] [Indexed: 05/28/2023] Open
Abstract
Alzheimer disease (AD) models are based on the notion that abnormal protein aggregation is the primary event in AD, which begins a decade or longer prior to symptom onset, and culminates in neurodegeneration; however, emerging evidence from animal and clinical studies suggests that reduced blood flow due to capillary loss and endothelial dysfunction are early and primary events in AD pathogenesis, which may precede amyloid and tau aggregation, and contribute to neuronal and synaptic injury via direct and indirect mechanisms. Recent data from clinical studies suggests that endothelial dysfunction is closely associated with cognitive outcomes in AD and that therapeutic strategies which promote endothelial repair in early AD may offer a potential opportunity to prevent or slow disease progression. This review examines evidence from clinical, imaging, neuropathological, and animal studies supporting vascular contributions to the onset and progression of AD pathology. Together, these observations support the notion that the onset of AD may be primarily influenced by vascular, rather than neurodegenerative, mechanisms and emphasize the importance of further investigations into the vascular hypothesis of AD.
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Affiliation(s)
- Rawan Tarawneh
- Department of Neurology, Center for Memory and Aging, University of New Mexico, Albuquerque, NM 87106, USA
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Fragas MG, Cândido VB, Davanzo GG, Rocha-Santos C, Ceroni A, Michelini LC. Transcytosis within PVN capillaries: a mechanism determining both hypertension-induced blood-brain barrier dysfunction and exercise-induced correction. Am J Physiol Regul Integr Comp Physiol 2021; 321:R732-R741. [PMID: 34549626 DOI: 10.1152/ajpregu.00154.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 09/17/2021] [Indexed: 11/22/2022]
Abstract
Although hypertension disrupts the blood-brain barrier (BBB) integrity within the paraventricular nucleus of hypothalamus (PVN) and increases the leakage into the brain parenchyma, exercise training (T) was shown to correct it. Since there is scarce and contradictory information on the mechanism(s) determining hypertension-induced BBB deficit and nothing is known about T-induced improvement, we sought to evaluate the paracellular and transcellular transport across the BBB within the PVN in both conditions. Spontaneously hypertensive rats (SHR) and WKY submitted to 4-wk aerobic T or sedentary (S) protocol were chronically catheterized for hemodynamic recordings at rest and intra-arterial administration of dyes (Rhodamine-dextran 70 kDa + FITC-dextran 10 kDa). Brains were harvesting for FITC leakage examination, qPCR evaluation of different BBB constituents and protein expression of caveolin-1 and claudin-5, the main markers of transcytosis and paracellular transport, respectively. Hypertension was characterized by increased arterial pressure and heart rate, augmented sympathetic modulation of heart and vessels, and reduced cardiac parasympathetic control, marked FITC extravasation into the PVN which was accompanied by increased caveolin-1 gene and protein expression, without changes in claudin-5 and others tight junctions' components. SHR-T vs. SHR-S showed a partial pressure reduction, resting bradycardia, improvement of autonomic control of the circulation simultaneously with correction of both FITC leakage and caveolin-1 expression; there was a significant increase in claudin-5 expression. Caveolin-1 content was strongly correlated with improved autonomic control after exercise. Data indicated that within the PVN the transcytosis is the main mechanism governing both hypertension-induced BBB leakage, as well as the exercise-induced correction.
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Affiliation(s)
- Matheus Garcia Fragas
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, São Paulo, Brazil
| | - Vanessa Brito Cândido
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, São Paulo, Brazil
| | - Gustavo Gastão Davanzo
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, São Paulo, Brazil
| | - Carla Rocha-Santos
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, São Paulo, Brazil
| | - Alexandre Ceroni
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, São Paulo, Brazil
| | - Lisete C Michelini
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, São Paulo, Brazil
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Cerniello FM, Silva MG, Carretero OA, Gironacci MM. Mas receptor is translocated to the nucleus upon agonist stimulation in brainstem neurons from spontaneously hypertensive rats but not normotensive rats. Cardiovasc Res 2021; 116:1995-2008. [PMID: 31825460 DOI: 10.1093/cvr/cvz332] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 10/31/2019] [Accepted: 12/09/2019] [Indexed: 12/23/2022] Open
Abstract
AIMS Activation of the angiotensin (Ang)-(1-7)/Mas receptor (R) axis protects from sympathetic overactivity. Endocytic trafficking is an essential process that regulates receptor (R) function and its ultimate cellular responses. We investigated whether the blunted responses to Ang-(1-7) in hypertensive rats are associated to an alteration in MasR trafficking. METHODS AND RESULTS Brainstem neurons from Wistar-Kyoto (WKY) or spontaneously hypertensive rats (SHRs) were investigated for (i) Ang-(1-7) levels and binding and MasR expression, (ii) Ang-(1-7) responses (arachidonic acid and nitric oxide release and Akt and ERK1/2 phosphorylation), and (iii) MasR trafficking. Ang-(1-7) was determined by radioimmunoassay. MasR expression and functionality were evaluated by western blot and binding assays. MasR trafficking was evaluated by immunofluorescence. Ang-(1-7) treatment induced an increase in nitric oxide and arachidonic acid release and ERK1/2 and Akt phosphorylation in WKY neurons but did not have an effect in SHR neurons. Although SHR neurons showed greater MasR expression, Ang-(1-7)-elicited responses were substantially diminished presumably due to decreased Ang-(1-7) endogenous levels concomitant with impaired binding to its receptor. Through immunocolocalization studies, we evidenced that upon Ang-(1-7) stimulation MasRs were internalized through clathrin-coated pits and caveolae into early endosomes and slowly recycled back to the plasma membrane. However, the fraction of internalized MasRs into early endosomes was larger and the fraction of MasRs recycled back to the plasma membrane was smaller in SHR than in WKY neurons. Surprisingly, in SHR neurons but not in WKY neurons, Ang-(1-7) induced MasR translocation to the nucleus. Nuclear MasR expression and Ang-(1-7) levels were significantly greater in the nuclei of Ang-(1-7)-stimulated SHR neurons, indicating that the MasR is translocated with its ligand bound to it. CONCLUSION MasRs display differential trafficking in brainstem neurons from SHRs, which may contribute to the impaired responses to Ang-(1-7).
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Affiliation(s)
- Flavia M Cerniello
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, IQUIFIB (UBA-CONICET), Dpto. Química Biológica, Junín 956, 1113, Buenos Aires, Argentina
| | - Mauro G Silva
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, IQUIFIB (UBA-CONICET), Dpto. Química Biológica, Junín 956, 1113, Buenos Aires, Argentina
| | - Oscar A Carretero
- Hypertension and Vascular Research Division, Henry Ford Hospital, Detroit, MI, USA
| | - Mariela M Gironacci
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, IQUIFIB (UBA-CONICET), Dpto. Química Biológica, Junín 956, 1113, Buenos Aires, Argentina
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Blood Pressure Profiles and Cognitive Function from Adulthood to Old Age: Chasing a Golden Middle Way? J Clin Med 2021; 10:jcm10153243. [PMID: 34362026 PMCID: PMC8347724 DOI: 10.3390/jcm10153243] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 07/17/2021] [Accepted: 07/21/2021] [Indexed: 12/17/2022] Open
Abstract
With the demographic shift toward advanced ages, it is imperative to understand the biological mechanisms behind common, disabling age-related diseases such as cognitive impairment in its mild form to overt dementia. Hypertension, a major cardiovascular risk factor, is epidemiologically linked to vascular and Alzheimer-type dementia, with possible mechanisms being atherosclerotic macro- and microvascular damage leading to neuronal cell death, as well as proinflammatory events responsible for neurodegeneration. Nevertheless, there is currently a knowledge gap as to which population to target, what the diagnostics test, and how to manage early pathogenic events in order to prevent such a dramatic and disabling condition. While clinical trials data support the benefit of active BP control with antihypertensive medications on the risk of future cognitive impairment, hypotension appears to be related to accelerated cognitive decline in both the fit and the cognitively frail elderly. Dedicated, technologically advanced studies assessing the relation of BP with dementia are needed to clarify the pathophysiological mechanisms in the association before a tailored preventive, diagnostic, and therapeutic approach to one of the most widespread modern medical challenges becomes a reality.
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Hypertension and Its Impact on Stroke Recovery: From a Vascular to a Parenchymal Overview. Neural Plast 2019; 2019:6843895. [PMID: 31737062 PMCID: PMC6815533 DOI: 10.1155/2019/6843895] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 08/30/2019] [Indexed: 12/14/2022] Open
Abstract
Hypertension is the first modifiable vascular risk factor accounting for 10.4 million deaths worldwide; it is strongly and independently associated with the risk of stroke and is related to worse prognosis. In addition, hypertension seems to be a key player in the implementation of vascular cognitive impairment. Long-term hypertension, complicated or not by the occurrence of ischemic stroke, is often reviewed on its vascular side, and parenchymal consequences are put aside. Here, we sought to review the impact of isolated hypertension or hypertension associated to stroke on brain atrophy, neuron connectivity and neurogenesis, and phenotype modification of microglia and astrocytes. Finally, we discuss the impact of antihypertensive therapies on cell responses to hypertension and functional recovery. This attractive topic remains a focus of continued investigation and stresses the relevance of including this vascular risk factor in preclinical investigations of stroke outcome.
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da Costa KG, Price M, Bortolotti H, de Medeiros Rêgo ML, Cabral DAR, Langer RD, Fernandes GA, Elsangedy HM, Fontes EB. Fat mass predicts food-specific inhibitory control in children. Physiol Behav 2019; 204:155-161. [DOI: 10.1016/j.physbeh.2019.02.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 02/24/2019] [Accepted: 02/24/2019] [Indexed: 02/06/2023]
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Rêgo MLM, Cabral DAR, Costa EC, Fontes EB. Physical Exercise for Individuals with Hypertension: It Is Time to Emphasize its Benefits on the Brain and Cognition. CLINICAL MEDICINE INSIGHTS-CARDIOLOGY 2019; 13:1179546819839411. [PMID: 30967748 PMCID: PMC6444761 DOI: 10.1177/1179546819839411] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 02/27/2019] [Indexed: 01/01/2023]
Abstract
Hypertension affects more than 40% of adults worldwide and is associated with stroke, myocardial infarction, heart failure, and other cardiovascular diseases. It has also been shown to cause severe functional and structural damage to the brain, leading to cognitive impairment and dementia. Furthermore, it is believed that these cognitive impairments affect the mental ability to maintain productivity at work, ultimately causing social and economic problems. Because hypertension is a chronic condition that requires clinical treatment, strategies with fewer side effects and less-invasive procedures are needed. Physical exercise (PE) has proven to be an efficient and complementary tool for hypertension management, and its peripheral benefits have been widely supported by related studies. However, few studies have specifically examined the potential positive effects of PE on the brain in hypertensive individuals. This narrative review discusses the pathophysiological mechanisms that hypertension promotes in the brain, and suggests PE as an important tool to prevent and reduce cognitive damage caused by hypertension. We also provide PE recommendations for hypertensive individuals, as well as suggestions for promoting PE as a method for increasing cognitive abilities in the brain, particularly for hypertensive individuals.
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Affiliation(s)
- Maria LM Rêgo
- NEUROEX-Research Group in Physical
Activity, Cognition and Behavior, Health Science Center, Federal University of Rio
Grande do Norte, Natal/RN, Brazil
| | - Daniel AR Cabral
- NEUROEX-Research Group in Physical
Activity, Cognition and Behavior, Health Science Center, Federal University of Rio
Grande do Norte, Natal/RN, Brazil
| | - Eduardo C Costa
- GPEACE-Research Group on Acute and
Chronic Effects of Exercise, Health Science Center, Federal University of Rio Grande
do Norte, Natal/RN, Brazil
| | - Eduardo B Fontes
- NEUROEX-Research Group in Physical
Activity, Cognition and Behavior, Health Science Center, Federal University of Rio
Grande do Norte, Natal/RN, Brazil
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Koundal S, Liu X, Sanggaard S, Mortensen K, Wardlaw J, Nedergaard M, Benveniste H, Lee H. Brain Morphometry and Longitudinal Relaxation Time of Spontaneously Hypertensive Rats (SHRs) in Early and Intermediate Stages of Hypertension Investigated by 3D VFA-SPGR MRI. Neuroscience 2019; 404:14-26. [PMID: 30690138 DOI: 10.1016/j.neuroscience.2019.01.030] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Revised: 01/15/2019] [Accepted: 01/18/2019] [Indexed: 02/03/2023]
Abstract
Cerebral small vessel disease(s) (SVD) results from pathological changes of the small blood vessels in the brain and is common in older people. The diagnostic features by which SVD manifests in brain includes white matter hyperintensities, lacunes, dilated perivascular spaces, microbleeds, and atrophy. In the present study, we use in vivo magnetic resonance imaging (MRI) to characterize brain morphometry and longitudinal relaxation time (T1) of spontaneously hypertensive rats (SHRs) to study the contribution of chronic hypertension to SVD relevant pathology. Male SHR and Wistar-Kyoto (WKY) rats underwent 3D variable flip angle spoiled gradient echo brain MRI at 9.4 T at early (seven weeks old) and established (19 weeks old) stages of hypertension. The derived proton density weighted and T1 images were utilized for morphometry and to characterize T1 properties in gray matter (GM), white matter (WM) and cerebrospinal fluid (CSF). Custom tissue probability maps were constructed for accurate computerized whole brain tissue segmentations and voxel-wise analyses. Characteristic morphological differences between the two strains included enlarged ventricles, smaller corpus callosum (CC) volumes and general 'thinning' of CC in SHR compared to WKY rats at both age groups. While we did not observe parenchymal T1 differences, the T1 of CSF was elevated in SHR compared to controls. Collectively these findings indicate that SHRs develop WM atrophy which is a clinically robust MRI biomarker associated with WM degeneration.
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Affiliation(s)
- Sunil Koundal
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, United States of America
| | - Xiaodan Liu
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, United States of America
| | - Simon Sanggaard
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, United States of America
| | - Kristian Mortensen
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Joanna Wardlaw
- Center for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, UK; UK Dementia Research Institute at The University of Edinburgh, The University of Edinburgh, Edinburgh, UK; Row Fogo Centre for Research into Ageing and the Brain, The University of Edinburgh, Edinburgh, UK
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Division of Glia Disease and Therapeutics, Center for Translational Neuromedicine, University of Rochester Medical School, Rochester, NY, USA
| | - Helene Benveniste
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, United States of America
| | - Hedok Lee
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, United States of America.
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Kilic-Toprak E, Kilic-Erkek O, Abban-Mete G, Caner V, Baris IC, Turhan G, Kucukatay V, Senol H, Kuru O, Bor-Kucukatay M. Contribution of Heme Oxygenase 2 to Blood Pressure Regulation in Response to Swimming Exercise and Detraining in Spontaneously Hypertensive Rats. Med Sci Monit 2018; 24:5851-5859. [PMID: 30132448 PMCID: PMC6116639 DOI: 10.12659/msm.908992] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Background We aimed to determine the effects of exercise followed by detraining on systolic blood pressure (SBP), heme oxygenase 2 (HO-2) expression, and carboxyhemoglobin (COHb) concentration in spontaneously hypertensive rats (SHR) to explain the role of carbon monoxide (CO) in this process. Material/Methods Animals were randomized into exercised and detrained groups. Corresponding sedentary rats were grouped as Time 1–2. Swimming of 60 min/5 days/week for 10 weeks was applied. Detraining rats discontinued training for an additional 5 weeks. Gene and protein expressions were determined by real-time PCR and immunohistochemistry. Results Aorta HO-2 histological scores (HSCORE) of hypertensive rats were lower, while SBP was higher. Swimming caused enhancement of HO-2 immunostaining in aorta endothelium and adventitia of SHR. Exercise induced elevation of blood COHb index in SHR. Synchronous BP lowering effect of exercise was observed. HO-2 mRNA expression, HSCORE, and blood COHb index were unaltered during detraining, while SBP was still low in SHR. Conclusions CO synthesized by HO-2 at least partly plays a role in SBP regulation in the SHR- and BP-lowering effect of exercise. Regular exercise with short-term pauses may be advised to both hypertensives and individuals who are at risk.
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Affiliation(s)
- Emine Kilic-Toprak
- Department of Physiology, Faculty of Medicine, Pamukkale University, Denizli, Turkey
| | - Ozgen Kilic-Erkek
- Department of Physiology, Faculty of Medicine, Pamukkale University, Denizli, Turkey
| | - Gulcin Abban-Mete
- Department of Histology-Embryology, Faculty of Medicine, Pamukkale University, Denizli, Turkey
| | - Vildan Caner
- Department of Medical Genetics, Faculty of Medicine Kinikli, Pamukkale University, Denizli, Turkey
| | - Ikbal Cansu Baris
- Department of Medical Biology, Faculty of Medicine, Pamukkale University, Denizli, Turkey
| | - Gurkan Turhan
- Department of Histology-Embryology, Faculty of Medicine, Pamukkale University, Denizli, Turkey
| | - Vural Kucukatay
- Department of Physiology, Faculty of Medicine, Pamukkale University, Denizli, Turkey
| | - Hande Senol
- Department of Biostatistics, Faculty of Medicine, Pamukkale University, Denizli, Turkey
| | - Oktay Kuru
- Department of Physiotherapy and Rehabilitation, Faculty of Health Sciences, Muğla Sıtkı Koçman University, Muğla, Turkey
| | - Melek Bor-Kucukatay
- Department of Physiology, Faculty of Medicine, Pamukkale University, Denizli, Turkey
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Buttler L, Jordão MT, Fragas MG, Ruggeri A, Ceroni A, Michelini LC. Maintenance of Blood-Brain Barrier Integrity in Hypertension: A Novel Benefit of Exercise Training for Autonomic Control. Front Physiol 2017; 8:1048. [PMID: 29311978 PMCID: PMC5733101 DOI: 10.3389/fphys.2017.01048] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 11/30/2017] [Indexed: 12/27/2022] Open
Abstract
The blood-brain barrier (BBB) is a complex multicellular structure acting as selective barrier controlling the transport of substances between these compartments. Accumulating evidence has shown that chronic hypertension is accompanied by BBB dysfunction, deficient local perfusion and plasma angiotensin II (Ang II) access into the parenchyma of brain areas related to autonomic circulatory control. Knowing that spontaneously hypertensive rats (SHR) exhibit deficient autonomic control and brain Ang II hyperactivity and that exercise training is highly effective in correcting both, we hypothesized that training, by reducing Ang II content, could improve BBB function within autonomic brain areas of the SHR. After confirming the absence of BBB lesion in the pre-hypertensive SHR, but marked fluorescein isothiocyanate dextran (FITC, 10 kD) leakage into the brain parenchyma of the hypothalamic paraventricular nucleus (PVN), nucleus of the solitary tract, and rostral ventrolateral medulla during the established phase of hypertension, adult SHR, and age-matched WKY were submitted to a treadmill training (T) or kept sedentary (S) for 8 weeks. The robust FITC leakage within autonomic areas of the SHR-S was largely reduced and almost normalized since the 2nd week of training (T2). BBB leakage reduction occurred simultaneously and showed strong correlations with both decreased LF/HF ratio to the heart and reduced vasomotor sympathetic activity (power spectral analysis), these effects preceding the appearance of resting bradycardia (T4) and partial pressure fall (T8). In other groups of SHR-T simultaneously infused with icv Ang II or saline (osmotic mini-pumps connected to a lateral ventricle cannula) we proved that decreased local availability of this peptide and reduced microglia activation (IBA1 staining) are crucial mechanisms conditioning the restoration of BBB integrity. Our data also revealed that Ang II-induced BBB lesion was faster within the PVN (T2), suggesting the prominent role of this nucleus in driven hypertension-induced deficits. These original set of data suggest that reduced local Ang II content (and decreased activation of its downstream pathways) is an essential and early-activated mechanism to maintain BBB integrity in trained SHR and uncovers a novel beneficial effect of exercise training to improve autonomic control even in the presence of hypertension.
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Affiliation(s)
- Leila Buttler
- Department Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Maria T Jordão
- Department Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Matheus G Fragas
- Department Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Adriana Ruggeri
- Department Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Alexandre Ceroni
- Department Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Lisete C Michelini
- Department Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
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Kilic-Erkek O, Kilic-Toprak E, Caliskan S, Ekbic Y, Akbudak IH, Kucukatay V, Bor-Kucukatay M. Detraining reverses exercise-induced improvement in blood pressure associated with decrements of oxidative stress in various tissues in spontaneously hypertensive rats. Mol Cell Biochem 2015; 412:209-19. [DOI: 10.1007/s11010-015-2627-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 12/15/2015] [Indexed: 11/30/2022]
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13
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Toth P, Csiszar A, Sosnowska D, Tucsek Z, Cseplo P, Springo Z, Tarantini S, Sonntag WE, Ungvari Z, Koller A. Treatment with the cytochrome P450 ω-hydroxylase inhibitor HET0016 attenuates cerebrovascular inflammation, oxidative stress and improves vasomotor function in spontaneously hypertensive rats. Br J Pharmacol 2015. [PMID: 23194285 DOI: 10.1111/bph.12079] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND AND PURPOSE Hypertension increases cerebrovascular oxidative stress and inflammation and impairs vasomotor function. These pathological alterations lead to dysregulation of cerebral blood flow and exacerbate atherogenesis, increasing the morbidity of ischaemic cerebrovascular diseases and promoting vascular cognitive impairment. We aimed to test the hypothesis that increased production of the arachidonic acid metabolite 20-hydroxy-5,8,11,14-eicosatetraenoic acid (20-HETE) contributes to hypertension-induced cerebrovascular alterations. EXPERIMENTAL APPROACH We treated male spontaneously hypertensive rats (SHR) with HET0016 (N-hydroxy-N'-(4-butyl-2-methylphenyl)-formamidine), an inhibitor of 20-HETE synthesis. In middle cerebral arteries (MCAs) of SHRs, we focused on vasomotor responses and end points that are highly relevant for cellular reactive oxygen species (ROS) production, inflammatory cytokine expression and NF-κB activation. KEY RESULTS SHRs treated with HET0016 remained hypertensive (SHR + HET0016: 149 ± 8 mmHg, Wistar-Kyoto rat: 115 ± 4 mmHg; P < 0.05.), although their systolic blood pressure was decreased compared to untreated SHRs (191 ± 6 mmHg). In MCAs of SHRs, flow-induced constriction was increased, whereas ACh- and ATP-induced dilations were impaired. This functional impairment was reversed by treatment with HET0016. Treatment with HET0016 also significantly decreased oxidative stress in MCAs of SHRs (as shown by dihydroethidium staining and analysis of vascular 5-nitrotyrosine, 4-hydroxynonenal and carbonyl content) and inhibited cerebrovascular inflammation (shown by the reduced mRNA expression of TNFα, IL-1β and IL-6). Treatment of SHRs with HET0016 also attenuated vascular NF-κB activation. In vitro treatment with 20-HETE significantly increased vascular production of ROS and promoted NF-κB activation in cultured cerebromicrovascular endothelial cells. CONCLUSIONS AND IMPLICATIONS Taken together, treatment with HET0016 confers anti-oxidative and anti-inflammatory effects in the cerebral arteries of SHRs by disrupting 20-HETE-mediated autocrine/paracrine signalling pathways in the vascular wall. It is likely that HET0016-induced decreases in blood pressure also potentiate the cerebrovascular protective effects of the drug.
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Affiliation(s)
- Peter Toth
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma, Oklahoma City, OK 73104, USA
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López-Gil X, Amat-Roldan I, Tudela R, Castañé A, Prats-Galino A, Planas AM, Farr TD, Soria G. DWI and complex brain network analysis predicts vascular cognitive impairment in spontaneous hypertensive rats undergoing executive function tests. Front Aging Neurosci 2014; 6:167. [PMID: 25100993 PMCID: PMC4107676 DOI: 10.3389/fnagi.2014.00167] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 06/30/2014] [Indexed: 01/09/2023] Open
Abstract
The identification of biomarkers of vascular cognitive impairment is urgent for its early diagnosis. The aim of this study was to detect and monitor changes in brain structure and connectivity, and to correlate them with the decline in executive function. We examined the feasibility of early diagnostic magnetic resonance imaging (MRI) to predict cognitive impairment before onset in an animal model of chronic hypertension: Spontaneously Hypertensive Rats. Cognitive performance was tested in an operant conditioning paradigm that evaluated learning, memory, and behavioral flexibility skills. Behavioral tests were coupled with longitudinal diffusion weighted imaging acquired with 126 diffusion gradient directions and 0.3 mm3 isometric resolution at 10, 14, 18, 22, 26, and 40 weeks after birth. Diffusion weighted imaging was analyzed in two different ways, by regional characterization of diffusion tensor imaging (DTI) indices, and by assessing changes in structural brain network organization based on Q-Ball tractography. Already at the first evaluated times, DTI scalar maps revealed significant differences in many regions, suggesting loss of integrity in white and gray matter of spontaneously hypertensive rats when compared to normotensive control rats. In addition, graph theory analysis of the structural brain network demonstrated a significant decrease of hierarchical modularity, global and local efficacy, with predictive value as shown by regional three-fold cross validation study. Moreover, these decreases were significantly correlated with the behavioral performance deficits observed at subsequent time points, suggesting that the diffusion weighted imaging and connectivity studies can unravel neuroimaging alterations even overt signs of cognitive impairment become apparent.
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Affiliation(s)
- Xavier López-Gil
- Experimental 7T MRI Unit, IDIBAPS, Institut d'Investigacions Biomèdiques August Pi i Sunyer Barcelona, Spain
| | | | - Raúl Tudela
- Experimental 7T MRI Unit, IDIBAPS, Institut d'Investigacions Biomèdiques August Pi i Sunyer Barcelona, Spain ; Group of Biomedical Imaging of the University of Barcelona, CIBER de Bioingenieria, Biomateriales y Nanomedicina Barcelona, Spain
| | - Anna Castañé
- Department of Neurochemistry and Neuropharmacology, Institut d'Investigacions Biomèdiques de Barcelona (IIBB-CSIC) Barcelona, Spain ; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), ISCIII Madrid, Spain
| | - Alberto Prats-Galino
- Human Anatomy and Embryology Unit, Laboratory of Surgical NeuroAnatomy, Facultat de Medicina, Universitat de Barcelona Barcelona, Spain
| | - Anna M Planas
- Department of Brain Ischemia and Neurodegeneration, Institut d'Investigacions Biomèdiques de Barcelona (IIBB-CSIC) Barcelona, Spain
| | - Tracy D Farr
- Department of Experimental Neurology, Center for Stroke Research Berlin Charité, Berlin, Germany
| | - Guadalupe Soria
- Experimental 7T MRI Unit, IDIBAPS, Institut d'Investigacions Biomèdiques August Pi i Sunyer Barcelona, Spain ; Group of Biomedical Imaging of the University of Barcelona, CIBER de Bioingenieria, Biomateriales y Nanomedicina Barcelona, Spain
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15
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Kang BT, Leoni RF, Silva AC. Impaired CBF regulation and high CBF threshold contribute to the increased sensitivity of spontaneously hypertensive rats to cerebral ischemia. Neuroscience 2014; 269:223-31. [PMID: 24680939 DOI: 10.1016/j.neuroscience.2014.03.031] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 03/03/2014] [Accepted: 03/17/2014] [Indexed: 01/26/2023]
Abstract
The correlation between temporal changes of regional cerebral blood flow (rCBF) and the severity of transient ischemic stroke in spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY) was investigated using T2-, diffusion- and perfusion-weighted magnetic resonance imaging at six different time points: before and during 1h of unilateral middle cerebral artery occlusion (MCAO), 1h after reperfusion, and 1 day, 4 days and 7 days after MCAO. rCBF values were measured in both hemispheres, and the perfusion-deficient lesion (PDL) was defined as the area of the brain with a 57% or more reduction in basal CBF. Within the PDL, regions were further refined as ischemic core (rCBF=0-6 mL/100 g/min), ischemic penumbra (rCBF=6-15 mL/100 g/min) and benign oligemia (rCBF>15 mL/100 g/min). SHR and WKY had identical initial volume of the PDLs (WKY: 32.52 ± 4.08% vs. SHR: 33.95 ± 3.68%; P>0.05) and the maximum rCBF measured within those lesions (WKY: 38.20 ± 3.57 mL/100g/min vs. SHR: 38.46 ± 6.22 mL/100 g/min; P>0.05) during MCAO. However, in SHR virtually all of the PDL progressed to become the final ischemic lesion (33.02 ± 5.41%, P>0.05), while the final ischemic lesion volume of WKY (12.62 ± 9.19%) was significantly smaller than their original PDL (P<0.01) and similar to the ischemic core (13.13 ± 2.96%, P>0.05). The region with the lowest range of rCBF was positively correlated with the final ischemic lesion volume (r=0.716, P<0.01). Both during ischemia and after reperfusion, rCBF in either ipsilesional and contralesional brain hemispheres of SHR could not be restored to pre-ischemic levels, and remained lower than in WKY until up to 4 days after MCAO. The data suggest that impaired CBF regulation and relatively high CBF threshold for ischemia are strong contributors to the increased susceptibility of SHR to ischemic stroke.
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Affiliation(s)
- B-T Kang
- Cerebral Microcirculation Unit, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA; Laboratory of Molecular Imaging and Translational Research, College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk, South Korea
| | - R F Leoni
- Cerebral Microcirculation Unit, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA; Department of Neuroscience and Behavioral Sciences, FMRP, University of Sao Paulo, Ribeirao Preto, Brazil
| | - A C Silva
- Cerebral Microcirculation Unit, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
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16
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Kim T, Richard Jennings J, Kim SG. Regional cerebral blood flow and arterial blood volume and their reactivity to hypercapnia in hypertensive and normotensive rats. J Cereb Blood Flow Metab 2014; 34:408-14. [PMID: 24252849 PMCID: PMC3948115 DOI: 10.1038/jcbfm.2013.197] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 10/15/2013] [Accepted: 10/21/2013] [Indexed: 11/09/2022]
Abstract
Chronic hypertension induces cerebrovascular remodeling, changing the inner diameter and elasticity of arterial vessels. To examine cerebrovascular morphologic changes and vasodilatory impairment in early-stage hypertension, we measured baseline (normocapnic) cerebral arterial blood volume (CBV(a)) and cerebral blood flow (CBF) as well as hypercapnia-induced dynamic vascular responses in animal models. All experiments were performed with young (3 to 4 month old) spontaneously hypertensive rats (SHR) and control Wistar-Kyoto rats (WKY) under ∼1% isoflurane anesthesia at 9.4 Tesla. Baseline regional CBF values were similar in both animal groups, whereas SHR had significantly lower CBV(a) values, especially in the hippocampus area. As CBF is maintained by adjusting arterial diameters within the autoregulatory blood pressure range, CBV(a) is likely more sensitive than CBF for detecting hypertensive-mediated alterations. Unexpectedly, hypercapnia-induced CBF and blood-oxygenation-level-dependent (BOLD) response were significantly higher in SHR as compared with WKY, and the CBF reactivity was highly correlated with the BOLD reactivity in both groups. The higher reactivity in early-stage hypertensive animals indicates no significant vascular remodeling occurred. At later stages of hypertension, the reduced vascular reactivity is expected. Thus, CBF and CBV(a) mapping may provide novel insights into regional cerebrovascular impairment in hypertension and its progression as hypertension advances.
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Affiliation(s)
- Tae Kim
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - J Richard Jennings
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Seong-Gi Kim
- 1] Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA [2] Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Daejeon, Republic of Korea [3] Department of Biological Sciences, Sungkyunkwan University, Suwon, Republic of Korea
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17
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Petkova Z, Tchekalarova J, Pechlivanova D, Moyanova S, Kortenska L, Mitreva R, Popov D, Markova P, Lozanov V, Atanasova D, Lazarov N, Stoynev A. Treatment with melatonin after status epilepticus attenuates seizure activity and neuronal damage but does not prevent the disturbance in diurnal rhythms and behavioral alterations in spontaneously hypertensive rats in kainate model of temporal lobe epilepsy. Epilepsy Behav 2014; 31:198-208. [PMID: 24440891 DOI: 10.1016/j.yebeh.2013.12.013] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 11/14/2013] [Accepted: 12/15/2013] [Indexed: 11/16/2022]
Abstract
Melatonin is involved in the control of circadian and seasonal rhythmicity, possesses potent antioxidant activity, and exerts a neuroprotective and anticonvulsant effect. Spontaneously hypertensive rats (SHRs) are widely accepted as an experimental model of essential hypertension with hyperactivity, deficient sustained attention, and alterations in circadian autonomic profiles. The purpose of the present study was to determine whether melatonin treatment during epileptogenesis can prevent the deleterious consequences of status epilepticus (SE) in SHRs in the kainate (KA) model of temporal lobe of epilepsy (TLE). Spontaneous recurrent seizures (SRSs) were EEG- and video-recorded during and after the treatment protocol. Melatonin (10mg/kg diluted in drinking water, 8weeks) increased the seizure-latent period, decreased the frequency of SRSs, and attenuated the circadian rhythm of seizure activity in SHRs. However, melatonin was unable to affect the disturbed diurnal rhythms and behavioral changes associated with epilepsy, including the decreased anxiety level, depression, and impaired spatial memory. Melatonin reduced neuronal damage specifically in the CA1 area of the hippocampus and piriform cortex and decreased hippocampal serotonin (5-HT) levels both in control and epileptic SHRs. Although long-term melatonin treatment after SE shows a potential to attenuate seizure activity and neuronal loss, it is unable to restore epilepsy-associated behavioral abnormalities in SHRs.
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Affiliation(s)
- Zlatina Petkova
- Institute of Neurobiology, Acad. G. Bonchev Str., Bl. 23, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria
| | - Jana Tchekalarova
- Institute of Neurobiology, Acad. G. Bonchev Str., Bl. 23, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria.
| | - Daniela Pechlivanova
- Institute of Neurobiology, Acad. G. Bonchev Str., Bl. 23, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria
| | - Slavianka Moyanova
- Institute of Neurobiology, Acad. G. Bonchev Str., Bl. 23, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria
| | - Lidia Kortenska
- Institute of Neurobiology, Acad. G. Bonchev Str., Bl. 23, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria
| | - Rumiana Mitreva
- Institute of Neurobiology, Acad. G. Bonchev Str., Bl. 23, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria
| | - Deyan Popov
- Institute of Neurobiology, Acad. G. Bonchev Str., Bl. 23, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria
| | - Petya Markova
- Institute of Neurobiology, Acad. G. Bonchev Str., Bl. 23, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria
| | - Valentin Lozanov
- Institute of Neurobiology, Acad. G. Bonchev Str., Bl. 23, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria
| | - Dimitrina Atanasova
- Institute of Neurobiology, Acad. G. Bonchev Str., Bl. 23, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria
| | - Nikolai Lazarov
- Institute of Neurobiology, Acad. G. Bonchev Str., Bl. 23, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria
| | - Alexander Stoynev
- Institute of Neurobiology, Acad. G. Bonchev Str., Bl. 23, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria
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18
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Calcinaghi N, Wyss MT, Jolivet R, Singh A, Keller AL, Winnik S, Fritschy JM, Buck A, Matter CM, Weber B. Multimodal imaging in rats reveals impaired neurovascular coupling in sustained hypertension. Stroke 2013; 44:1957-64. [PMID: 23735955 DOI: 10.1161/strokeaha.111.000185] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
BACKGROUND AND PURPOSE Arterial hypertension is an important risk factor for cerebrovascular diseases, such as transient ischemic attacks or stroke, and represents a major global health issue. The effects of hypertension on cerebral blood flow, particularly at the microvascular level, remain unknown. METHODS Using the spontaneously hypertensive rat (SHR) model, we examined cortical hemodynamic responses on whisker stimulation applying a multimodal imaging approach (multiwavelength spectroscopy, laser speckle imaging, and 2-photon microscopy). We assessed the effects of hypertension in 10-, 20-, and 40-week-old male SHRs and age-matched male Wistar Kyoto rats (CTRL) on hemodynamic responses, histology, and biochemical parameters. In 40-week-old animals, losartan or verapamil was administered for 10 weeks to test the reversibility of hypertension-induced impairments. RESULTS Increased arterial blood pressure was associated with a progressive impairment in functional hyperemia in 20- and 40-week-old SHRs; baseline capillary red blood cell velocity was increased in 40-week-old SHRs compared with age-matched CTRLs. Antihypertensive treatment reduced baseline capillary cerebral blood flow almost to CTRL values, whereas functional hyperemic signals did not improve after 10 weeks of drug therapy. Structural analyses of the microvascular network revealed no differences between normo- and hypertensive animals, whereas expression analyses of cerebral lysates showed signs of increased oxidative stress and signs of impaired endothelial homeostasis upon early hypertension. CONCLUSIONS Impaired neurovascular coupling in the SHR evolves upon sustained hypertension. Antihypertensive monotherapy using verapamil or losartan is not sufficient to abolish this functional impairment. These deficits in neurovascular coupling in response to sustained hypertension might contribute to accelerate progression of neurodegenerative diseases in chronic hypertension.
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Affiliation(s)
- Novella Calcinaghi
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
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19
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Kang BT, Leoni RF, Kim DE, Silva AC. Phenylephrine-induced hypertension during transient middle cerebral artery occlusion alleviates ischemic brain injury in spontaneously hypertensive rats. Brain Res 2012; 1477:83-91. [PMID: 22954904 PMCID: PMC3456967 DOI: 10.1016/j.brainres.2012.08.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Revised: 07/24/2012] [Accepted: 08/14/2012] [Indexed: 10/27/2022]
Abstract
Arterial hypertension is a major risk factor for ischemic stroke. However, the management of preexisting hypertension is still controversial in the treatment of acute stroke in hypertensive patients. The present study evaluates the influence of preserving hypertension during focal cerebral ischemia on stroke outcome in a rat model of chronic hypertension, the spontaneously hypertensive rats (SHR). Focal cerebral ischemia was induced by transient (1h) occlusion of the middle cerebral artery, during which mean arterial blood pressure was maintained at normotension (110-120mm Hg, group 1, n=6) or hypertension (160-170mm Hg, group 2, n=6) using phenylephrine. T2-, diffusion- and perfusion-weighted MRI were performed serially at five different time points: before and during ischemia, and at 1, 4 and 7 days after ischemia. Lesion volume and brain edema were estimated from apparent diffusion coefficient maps and T2-weighted images. Regional cerebral blood flow (rCBF) was measured within and outside the perfusion deficient lesion and in the corresponding regions of the contralesional hemisphere. Neurological deficits were evaluated after reperfusion. Infarct volume, edema, and neurological deficits were significantly reduced in group 2 vs. group 1. In addition, higher values and rapid restoration of rCBF were observed in group 2, while rCBF in both hemispheres was significantly decreased in group 1. Maintaining preexisting hypertension alleviates ischemic brain injury in SHR by increasing collateral circulation to the ischemic region and allowing rapid restoration of rCBF. The data suggest that maintaining preexisting hypertension is a valuable approach to managing hypertensive patients suffering from acute ischemic stroke.
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Affiliation(s)
- Byeong-Teck Kang
- Cerebral Microcirculation Unit, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
- Laboratory of Molecular Imaging and Translational Research, College of Veterinary Medicine, Chungbuk National University, Cheongju, South Korea
| | - Renata F. Leoni
- Cerebral Microcirculation Unit, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
- Department of Neuroscience and Behavioral Sciences, FMRP, University of Sao Paulo, Ribeirao Preto, Brazil
| | - Dong-Eog Kim
- Molecular Imaging and Neurovascular Research (MINER) Laboratory, Dongguk University Ilsan Hospital, Goyang, South Korea
| | - Afonso C. Silva
- Cerebral Microcirculation Unit, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
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20
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Ritz MF, Grond-Ginsbach C, Engelter S, Lyrer P. Gene expression suggests spontaneously hypertensive rats may have altered metabolism and reduced hypoxic tolerance. Curr Neurovasc Res 2012; 9:10-9. [PMID: 22272763 PMCID: PMC3296125 DOI: 10.2174/156720212799297074] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Revised: 12/07/2011] [Accepted: 12/15/2011] [Indexed: 12/27/2022]
Abstract
Cerebral small vessel disease (SVD) is an important cause of stroke, cognitive decline and vascular dementia (VaD). It is associated with diffuse white matter abnormalities and small deep cerebral ischemic infarcts. The molecular mechanisms involved in the development and progression of SVD are unclear. As hypertension is a major risk factor for developing SVD, Spontaneously Hypertensive Rats (SHR) are considered an appropriate experimental model for SVD. Prior work suggested an imbalance between the number of blood microvessels and astrocytes at the level of the neurovascular unit in 2-month-old SHR, leading to neuronal hypoxia in the brain of 9-month-old animals. To identify genes and pathways involved in the development of SVD, we compared the gene expression profile in the cortex of 2 and 9-month-old of SHR with age-matched normotensive Wistar Kyoto (WKY) rats using microarray-based technology. The results revealed significant differences in expression of genes involved in energy and lipid metabolisms, mitochondrial functions, oxidative stress and ischemic responses between both groups. These results strongly suggest that SHR suffer from chronic hypoxia, and therefore are unable to tolerate ischemia-like conditions, and are more vulnerable to high-energy needs than WKY. This molecular analysis gives new insights about pathways accounting for the development of SVD.
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Affiliation(s)
- Marie-Françoise Ritz
- Department of Biomedicine, Brain Tumor Biology Laboratory, Pharmazentrum, Klingelbergstrasse 50, 4056 Basel, Switzerland.
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21
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Leoni RF, Paiva FF, Kang BT, Henning EC, Nascimento GC, Tannús A, De Araújo DB, Silva AC. Arterial spin labeling measurements of cerebral perfusion territories in experimental ischemic stroke. Transl Stroke Res 2011; 3:44-55. [PMID: 24323754 DOI: 10.1007/s12975-011-0115-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Revised: 10/07/2011] [Accepted: 10/11/2011] [Indexed: 11/29/2022]
Abstract
Collateral circulation, defined as the supplementary vascular network that maintains cerebral blood flow (CBF) when the main vessels fail, constitutes one important defense mechanism of the brain against ischemic stroke. In the present study, continuous arterial spin labeling (CASL) was used to quantify CBF and obtain perfusion territory maps of the major cerebral arteries in spontaneously hypertensive rats (SHRs) and their normotensive Wistar-Kyoto (WKY) controls. Results show that both WKY and SHR have complementary, yet significantly asymmetric perfusion territories. Right or left dominances were observed in territories of the anterior (ACA), middle and posterior cerebral arteries, and the thalamic artery. Magnetic resonance angiography showed that some of the asymmetries were correlated with variations of the ACA. The leptomeningeal circulation perfusing the outer layers of the cortex was observed as well. Significant and permanent changes in perfusion territories were obtained after temporary occlusion of the right middle cerebral artery in both SHR and WKY, regardless of their particular dominance. However, animals with right dominance presented a larger volume change of the left perfusion territory (23 ± 9%) than animals with left dominance (7 ± 5%, P < 0.002). The data suggest that animals with contralesional dominance primarily safeguard local CBF values with small changes in contralesional perfusion territory, while animals with ipsilesional dominance show a reversal of dominance and a substantial increase in contralesional perfusion territory. These findings show the usefulness of CASL to probe the collateral circulation.
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Affiliation(s)
- Renata F Leoni
- Cerebral Microcirculation Unit, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 10 Center Drive MSC 1065, Building 10 Room B1D106, Bethesda, MD, 20892-1065, USA
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22
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Laser-induced carotid artery injury model in the rat for therapeutic agent screening. Lasers Med Sci 2011; 27:593-8. [DOI: 10.1007/s10103-011-0960-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2010] [Accepted: 06/29/2011] [Indexed: 10/17/2022]
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23
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Leoni RF, Paiva FF, Henning EC, Nascimento GC, Tannús A, de Araujo DB, Silva AC. Magnetic resonance imaging quantification of regional cerebral blood flow and cerebrovascular reactivity to carbon dioxide in normotensive and hypertensive rats. Neuroimage 2011; 58:75-81. [PMID: 21708273 DOI: 10.1016/j.neuroimage.2011.06.030] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Revised: 06/04/2011] [Accepted: 06/09/2011] [Indexed: 11/27/2022] Open
Abstract
Hypertension afflicts 25% of the general population and over 50% of the elderly. In the present work, arterial spin labeling MRI was used to non-invasively quantify regional cerebral blood flow (CBF), cerebrovascular resistance and CO(2) reactivity in spontaneously hypertensive rats (SHR) and in normotensive Wistar Kyoto rats (WKY), at two different ages (3 months and 10 months) and under the effects of two anesthetics, α-chloralose and 2% isoflurane (1.5 MAC). Repeated CBF measurements were highly consistent, differing by less than 10% and 18% within and across animals, respectively. Under α-chloralose, whole brain CBF at normocapnia did not differ between groups (young WKY: 61 ± 3ml/100g/min; adult WKY: 62 ± 4ml/100g/min; young SHR: 70 ± 9ml/100g/min; adult SHR: 69 ± 8ml/100g/min), indicating normal cerebral autoregulation in SHR. At hypercapnia, CBF values increased significantly, and a linear relationship between CBF and PaCO(2) levels was observed. In contrast, 2% isoflurane impaired cerebral autoregulation. Whole brain CBF in SHR was significantly higher than in WKY rats at normocapnia (young SHR: 139 ± 25ml/100g/min; adult SHR: 104 ± 23ml/100g/min; young WKY: 55± 9ml/100g/min; adult WKY: 71 ± 19ml/100g/min). CBF values increased significantly with increasing CO(2); however, there was a clear saturation of CBF at PaCO(2) levels greater than 70mmHg in both young and adult rats, regardless of absolute CBF values, suggesting that isoflurane interferes with the vasodilatory mechanisms of CO(2). This behavior was observed for both cortical and subcortical structures. Under either anesthetic, CO(2) reactivity values in adult SHR were decreased, confirming that hypertension, when combined with age, increases cerebrovascular resistance and reduces cerebrovascular compliance.
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Affiliation(s)
- Renata F Leoni
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD 20892-1065, USA
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Rodrigues A, Ferreira R, Salgado H, Fazan V. Morphometric analysis of the phrenic nerve in male and female Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR). Braz J Med Biol Res 2011; 44:583-91. [DOI: 10.1590/s0100-879x2011007500053] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2010] [Accepted: 04/15/2011] [Indexed: 11/22/2022] Open
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25
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Castelló-Ruiz M, Torregrosa G, Burguete MC, Salom JB, Gil JV, Miranda FJ, Jover-Mengual T, Marrachelli VG, Alborch E. Soy-derived phytoestrogens as preventive and acute neuroprotectors in experimental ischemic stroke: influence of rat strain. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2011; 18:513-5. [PMID: 21420287 DOI: 10.1016/j.phymed.2011.02.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The ability of a soy-based high-phytoestrogen diet (nutritional intervention) or genistein (pharmacological intervention), to limit ischemic brain damage in Wistar, Wistar-Kyoto (WKY) and spontaneously hypertensive (SHR) rats, has been assessed. As to the nutritional intervention, two groups from each strain received either a phytoestrogen-free (PE-0) or a high-phytoestrogen (PE-600) diet from weaning to adulthood. As to the pharmacological intervention, all animals were fed the standard soy-free AIN-93G diet and subsequently separated into two groups from each strain to receive either pure genistein (aglycone form, 1mg/kg/day intraperitoneal) or vehicle at 30 min reperfusion. After an episode of 90 min ischemia (intraluminal thread procedure) followed by 3 days reperfusion, cerebral infarct volume was measured. Arterial blood pressure (ABP) was significantly higher at the basal stage (just before ischemia) in SHR (140 ± 7 mmHg, n=17, p<0.05) than in Wistar (113 ± 4mmHg, n=23) and WKY (111 ± 6mmHg, n=14) rats. No significant differences were shown among the three stages (basal, ischemia, reperfusion) within each rat strain for both PE-0 and PE-600 diets. Wistar, but not WKY or SHR, rats fed the PE-600 diet showed significantly lower infarct volumes than their counterparts fed the PE-0 diet (30 ± 3% vs. 17 ± 3%, p<0.01). Genistein-treated Wistar, but not WKY or SHR, rats showed significantly lower infarct volumes than their vehicle-treated controls (27 ± 2% vs. 15 ± 2%, p<0.01). Our results demonstrate that: (1) the neuroprotective action of either chronic or acute exposure to soy isoflavones is strain-dependent, since it was shown in Wistar but not WKY or SHR rats; and (2) the soy-based diet does not prevent development of hypertension in SHR rats.
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Affiliation(s)
- M Castelló-Ruiz
- Centro de Investigación, Hospital Universitario La Fe, Ave. Campanar 21, 46009-Valencia, Spain; Departamento de Fisiología, Universidad de Valencia, Ave. Blasco Ibánez 15, 46010-Valencia, Spain
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Li D, Guo R, Chen QQ, Hu CP, Chen X. Increased plasma level of asymmetric dimethylarginine in hypertensive rats facilitates platelet aggregation: role of plasma tissue factor. Can J Physiol Pharmacol 2011; 89:151-8. [PMID: 21423288 DOI: 10.1139/y10-115] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
This study was designed to explore the role of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthesis, in platelet aggregation in hypertension and its possible mechanisms. Spontaneously hypertensive rats (SHR) and L-NAME-induced hypertensive rats were orally administered with L-arginine (1 g/(kg·day) for 14 days. Systolic blood pressure, platelet aggregation, and plasma tissue factor (TF) level and activity were measured. The plasma concentration of ADMA in SHR was determined. In vitro, platelet-rich plasma isolated from Wistar rats was prepared in order to observe the effect of exogenous ADMA on platelet aggregation and TF level and (or) activity in platelet-rich plasma. In both types of hypertensive rats, systolic blood pressure, platelet aggregation, and the level and activity of plasma TF were elevated compared with corresponding control animals. Plasma ADMA level was also increased in SHR. Treatment with L-arginine, a competitor of ADMA, lowered blood pressure and inhibited platelet aggregation concomitantly with a decrease in plasma TF level and activity in both types of hypertensive rats. We also found that exogenous ADMA promoted platelet aggregation and increased TF level and (or) activity in platelet-rich plasma, an effect that was inhibited by pretreatment with L-arginine. Importantly, the enhanced platelet aggregation induced by exogenous ADMA was reduced by pretreatment with anti-TF antibody. The results suggest that endogenous ADMA may be involved in platelet hyperaggregation status in hypertension, and the facilitation of platelet aggregation by ADMA is related to upregulation of the level and activity of plasma TF.
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Affiliation(s)
- Dai Li
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, China
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Sánchez F, Gómez-Villalobos MDJ, Juarez I, Quevedo L, Flores G. Dendritic morphology of neurons in medial prefrontal cortex, hippocampus, and nucleus accumbens in adult SH rats. Synapse 2010; 65:198-206. [DOI: 10.1002/syn.20837] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Increased serum S-100B and neuron specific enolase - Potential markers of early nervous system involvement in essential hypertension. Clin Biochem 2010; 44:154-9. [PMID: 21130083 DOI: 10.1016/j.clinbiochem.2010.11.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2010] [Revised: 11/03/2010] [Accepted: 11/21/2010] [Indexed: 11/21/2022]
Abstract
OBJECTIVES To investigate the occurrence of subclinical neurologic involvement in patients with essential hypertension employing serum biochemical markers. DESIGN AND METHODS Fifty patients with essential hypertension and 42 controls with no clinical evidence of neurological disease were recruited. Serum S100B protein and neuron specific enolase (NSE) were determined by employing immunoassay kits from CanAg Diagnostics AB (Sweden). Brain MRI and fundoscopic exploration were conducted. RESULTS S-100B and NSE levels were significantly higher in hypertensive patients than in controls. In hypertensive patients, multivariate analysis revealed that NSE was independently associated with two variables expressing severity of hypertension: diastolic blood pressure and grade of retinopathy. Brain MRI studies demonstrated higher NSE levels in patients with more severe white matter lesions. CONCLUSIONS Raised NSE levels are associated with a higher severity of hypertension and of white matter lesions, providing preliminary evidence that suggests the presence of silent brain damage in a subset of hypertensive patients.
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Jiwa NS, Garrard P, Hainsworth AH. Experimental models of vascular dementia and vascular cognitive impairment: a systematic review. J Neurochem 2010; 115:814-28. [PMID: 20731763 DOI: 10.1111/j.1471-4159.2010.06958.x] [Citation(s) in RCA: 189] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Vascular cognitive impairment (VCI) encompasses vascular dementia and is the second most common cause of dementing illness after Alzheimer's disease. The main causes of VCI are: cerebral small vessel disease; multi-infarct dementia; strategic infarct (i.e. located in a functionally-critical brain area); haemorrhage/microbleed; angiopathy (including cerebral amyloid angiopathy); severe hypoperfusion (e.g. cardiac arrhythmia); and hereditary vasculopathy (e.g. cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, CADASIL). In this systematic analysis, we aimed to relate cognitive and neuropathological features of experimental models to clinical VCI. We extracted data from 107 studies covering 16 models. These included: brief global ischaemic insults (in rats, mice or gerbils); chronic global hypoperfusion (rats, mice, gerbils); chronic hypertension (in primates or stroke-prone, spontaneously-hypertensive rats); multiple ischaemic lesions because of intra-vascular emboli (in rodents, rabbits or primates); strategic ischaemic lesions (in rats or mini-pigs); generalised vasculopathies, because of mutant Notch3, hyperhomocysteinaemia, experimental diabetes mellitus or lack of cerebral vasodilator M(5) receptors (rats or mice). Most cognitive testing showed deficits in working and reference memory. The lesions observed were microinfarcts, diffuse white matter lesions, hippocampal neuronal death, focal ischaemic lesions and micro-haemorrhages. The most-used model was bilateral carotid artery occlusion in rats, leading to chronic hypoperfusion and white matter injury.
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Affiliation(s)
- Nadim S Jiwa
- Clinical Neuroscience, Division of Clinical Sciences, St George's University of London, London, UK
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Tayebati S, Di Tullio M, Amenta F. Vesicular Acetylcholine Transporter (VAChT) in the Brain of Spontaneously Hypertensive Rats (SHR): Effect of Treatment with an Acetylcholinesterase Inhibitor. Clin Exp Hypertens 2009; 30:732-43. [DOI: 10.1080/10641960802580216] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Denniss SG, Rush JWE. Impaired hemodynamics and endothelial vasomotor function via endoperoxide-mediated vasoconstriction in the carotid artery of spontaneously hypertensive rats. Am J Physiol Heart Circ Physiol 2009; 296:H1038-47. [DOI: 10.1152/ajpheart.00933.2008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The fact that endothelium removal increases diameter and compliance in the common carotid artery (CCA) of spontaneously hypertensive rats (SHR) and that improving CCA endothelium-dependent vasorelaxation has been shown to normalize a reduced systolic blood flow through the SHR CCA compared with normotensive Wistar-Kyoto rats (WKY) suggests that endothelial vasomotor dysfunction may be linked to altered large artery hemodynamics in hypertension. The experiments herein were designed to further investigate WKY and SHR CCA hemodynamics and endothelium-dependent vasomotor functions. It was hypothesized that CCA blood flow and conductance would be reduced throughout the cardiac cycle in SHR and that endothelium-dependent contractile activity would impair SHR CCA vasorelaxation. We report that mean, maximal systolic, and diastolic blood flow was reduced in SHR vs. WKY CCA, as was vascular conductance. Pressure was augmented in SHR CCA and accompanied by late systolic flow augmentation so that total flow during systole was indeed no different between strains, possibly explained by earlier lower body wave reflection. While ACh stimulation in isolated precontracted WKY CCA caused a robust nitric oxide (NO)-mediated vasorelaxation, endothelium-dependent, cyclooxygenase (COX)-mediated contractile activity stimulated by high ACh concentration impaired NO- and non-NO/non-COX-mediated vasorelaxation in precontracted SHR CCA. In quiescent CCA, this endothelium-dependent contractile response was COX-1 and thromboxane-prostanoid receptor mediated and modulated by the availability of NO. These data collectively suggest that endothelium-dependent, COX-mediated endoperoxide signaling in the CCA of SHR may elicit vasoconstriction, which could shift the mechanical properties of this conduit artery and contribute to reduced CCA blood flow in vivo.
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Temma T, Kuge Y, Sano K, Kamihashi J, Obokata N, Kawashima H, Magata Y, Saji H. PET O-15 cerebral blood flow and metabolism after acute stroke in spontaneously hypertensive rats. Brain Res 2008; 1212:18-24. [DOI: 10.1016/j.brainres.2008.03.033] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2007] [Revised: 03/15/2008] [Accepted: 03/18/2008] [Indexed: 11/24/2022]
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Abstract
Postischemic neurogenesis has been identified as a compensatory mechanism to repair the damaged brain after stroke. Several factors are released by the ischemic tissue that are responsible for proliferation, differentiation, and migration of neural stem cells. An understanding of their roles may allow future therapies based on treatment with such factors. Although damaged cells release a variety of factors, some of them are stimulatory whereas some are inhibitory for neurogenesis. It is interesting to note that factors like insulin-like growth factor-I can induce proliferation in the presence of fibroblast growth factor-2 (FGF-2), and promote differentiation in the absence of FGF-2. Meanwhile, factors like transforming growth factor-beta can induce the differentiation of neurons while inhibiting the proliferation of neural stem cells. Therefore, understanding the role of each factor in the process of neurogenesis will help physicians to enhance the endogenous response and improve the clinical outcome after stroke. In this article the authors discuss the role of growth factors and stem cells following stroke.
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Affiliation(s)
- Haviryaji S G Kalluri
- Department of Neurological Surgery, University of Wisconsin, Madison, Wisconsin 53792, USA
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Ferrari MFR, Raizada MK, Fior-Chadi DR. Differential regulation of the renin-angiotensin system by nicotine in WKY and SHR glia. J Mol Neurosci 2008; 35:151-60. [PMID: 18369742 DOI: 10.1007/s12031-007-9025-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2007] [Accepted: 11/14/2007] [Indexed: 10/22/2022]
Abstract
Given that (1) the renin-angiotensin system (RAS) is compartmentalized within the central nervous system in neurons and glia (2) the major source of brain angiotensinogen is the glial cells, (3) the importance of RAS in the central control of blood pressure, and (4) nicotine increases the probability of development of hypertension associated to genetic predisposition; the objective of the present study was to evaluate the effects of nicotine on the RAS in cultured glial cells from the brainstem and hypothalamus of Wistar Kyoto (WKY) and spontaneously hypertensive (SHR) rats. Ligand binding, real-time PCR and western blotting assays were used to compare the expression of angiotensinogen, angiotensin converting enzyme, angiotensin converting enzyme 2 and angiotensin II type1 receptors. We demonstrate, for the first time, that there are significant differences in the basal levels of RAS components between WKY and SHR rats in glia from 1-day-old rats. We also observed that nicotine is able to modulate the renin-angiotensin system in glial cells from the brainstem and hypothalamus and that the SHR responses were more pronounced than WKY ones. The present data suggest that nicotine effects on the RAS might collaborate to the development of neurogenic hypertension in SHR through modulation of glial cells.
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Affiliation(s)
- Merari F R Ferrari
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, Travessa 14, n.321, Cidade Universitária, São Paulo, SP, 05508-090, Brazil.
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Lanari A, Silvestrelli G, De Dominicis P, Tomassoni D, Amenta F, Parnetti L. Arterial hypertension and cognitive dysfunction in physiologic and pathologic aging of the brain. ACTA ACUST UNITED AC 2007; 16:158-64. [PMID: 17483667 DOI: 10.1111/j.1076-7460.2007.06502.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Arterial hypertension is the most important modifiable cerebrovascular risk factor; its relationship with cerebrovascular disease is continuous, consistent, and independent. Different and probably converging pathophysiologic mechanisms explain the role of arterial hypertension in causing cognitive dysfunction in pathologic aging of the brain, specifically, vascular dementia and Alzheimer's disease.
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Affiliation(s)
- Alessia Lanari
- Section of Neurology, University of Perugia, Perugia, Italy
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37
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Asenjo García B, Moral Molero E. Diagnóstico radiológico de las lesiones cerebrales en pacientes con hipertensión arterial. HIPERTENSION Y RIESGO VASCULAR 2007. [DOI: 10.1016/s1889-1837(07)71680-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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38
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Al-Sarraf H, Ghaaedi F, Redzic Z. Time Course of Hyperosmolar Opening of the Blood-Brain and Blood-CSF Barriers in Spontaneously Hypertensive Rats. J Vasc Res 2006; 44:99-109. [PMID: 17191032 DOI: 10.1159/000098260] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2005] [Accepted: 10/14/2006] [Indexed: 11/19/2022] Open
Abstract
The time course of blood-brain barrier (BBB) and blood-CSF barrier (BCSFB) responses to hyperosmolar mannitol infusion (HMI; 1.6 M) during chronic hypertension was investigated using (14)C-sucrose as a marker of barrier integrity. (14)C-sucrose entry into CSF of both spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto (WKY) rats 2 min after HMI increased approximately 7-fold compared to their respective control. The volume of distribution (V(d)) of (14)C-sucrose into brain cortex of SHR increased 13-fold 2 min after HMI while that in WKY rats increased only 4-fold. After HMI V(d) of (14)C-sucrose into the cortex of WKY, and CSF of both SHR and WKY remained steadily greater than their corresponding control for up to 30 min (p < 0.01), whereas in the cortex of SHR the V(d) of (14)C-sucrose reached control values 20 min after HMI (p > 0.05), indicating that after HMI the increase in paracellular diffusion of (14)C-sucrose into SHR cortex was not persistent, in contrast to WKY rats and CSF of both SHR and WKY rats. Electron microscopy of the brain cortex after HMI showed capillary endothelial cell shrinkage and perivascular swellings in the brain cortex, and in the choroid plexus opening of tight junctions were observed. Our results indicate disruption of both the BBB and the BCSFB after HMI in both SHR and WKY rats. The disruption remained persistent up to 25 min after HMI at the BBB of WKY rats and BCSFB in both animal groups, while in SHR the protective function of the BBB returned to control values 20 min after HMI.
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Affiliation(s)
- Hameed Al-Sarraf
- Department of Physiology, Faculty of Medicine, Kuwait University, Safat, Kuwait.
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Tureyen K, Kapadia R, Bowen KK, Satriotomo I, Liang J, Feinstein DL, Vemuganti R. Peroxisome proliferator-activated receptor-γ agonists induce neuroprotection following transient focal ischemia in normotensive, normoglycemic as well as hypertensive and type-2 diabetic rodents. J Neurochem 2006; 101:41-56. [PMID: 17394460 DOI: 10.1111/j.1471-4159.2006.04376.x] [Citation(s) in RCA: 170] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Thiazolidinediones (TZDs) are synthetic agonists of the ligand-activated transcription factor peroxisome proliferator-activated receptor-gamma (PPARgamma). TZDs are known to curtail inflammation associated with peripheral organ ischemia. As inflammation precipitates the neuronal death after stroke, we tested the efficacy of TZDs in preventing brain damage following transient middle cerebral artery occlusion (MCAO) in adult rodents. As hypertension and diabetes complicate the stroke outcome, we also evaluated the efficacy of TZDs in hypertensive rats and type-2 diabetic mice subjected to transient MCAO. Pre-treatment as well as post-treatment with TZDs rosiglitazone and pioglitazone significantly decreased the infarct volume and neurological deficits in normotensive, normoglycemic, hypertensive and hyperglycemic rodents. Rosiglitazone neuroprotection was not enhanced by retinoic acid x receptor agonist 9-cis-retinoic acid, but was prevented by PPARgamma antagonist GW9662. Rosiglitazone significantly decreased the post-ischemic intercellular adhesion molecule-1 expression and extravasation of macrophages and neutrophils into brain. Rosiglitazone treatment curtailed the post-ischemic expression of the pro-inflammatory genes interleukin-1beta, interleukin-6, macrophage inflammatory protein-1alpha, monocyte chemoattractant protein-1, cyclooxygenase-2, inducible nitric oxide synthase, early growth response-1, CCAAT/enhancer binding protein-beta and nuclear factor-kappa B, and increased the expression of the anti-oxidant enzymes catalase and copper/zinc-superoxide dismutase. Rosiglitazone also increased the expression of the anti-inflammatory gene suppressor of cytokine signaling-3 and prevented the phosphorylation of the transcription factor signal transducer and activator of transcription-3 after focal ischemia. Thus, PPARgamma activation with TZDs might be a potent therapeutic option for preventing inflammation and neuronal damage after stroke with promise in diabetic and hypertensive subjects.
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MESH Headings
- Anilides/pharmacology
- Animals
- Cerebral Infarction/drug therapy
- Cerebral Infarction/physiopathology
- Cerebral Infarction/prevention & control
- Chemotaxis, Leukocyte/drug effects
- Chemotaxis, Leukocyte/physiology
- Cytokines/genetics
- Cytokines/metabolism
- Diabetes Mellitus, Type 2/genetics
- Diabetes Mellitus, Type 2/physiopathology
- Disease Models, Animal
- Encephalitis/drug therapy
- Encephalitis/metabolism
- Encephalitis/physiopathology
- Hypertension/genetics
- Hypertension/physiopathology
- Intercellular Adhesion Molecule-1/drug effects
- Intercellular Adhesion Molecule-1/metabolism
- Ischemic Attack, Transient/drug therapy
- Ischemic Attack, Transient/physiopathology
- Mice
- Mice, Inbred C57BL
- Mice, Mutant Strains
- Neuroprotective Agents/chemistry
- Neuroprotective Agents/pharmacology
- Neuroprotective Agents/therapeutic use
- PPAR gamma/agonists
- PPAR gamma/antagonists & inhibitors
- PPAR gamma/metabolism
- Pioglitazone
- Rats
- Rats, Inbred SHR
- Rats, Sprague-Dawley
- Rosiglitazone
- Superoxide Dismutase/drug effects
- Superoxide Dismutase/genetics
- Superoxide Dismutase/metabolism
- Superoxide Dismutase-1
- Suppressor of Cytokine Signaling 3 Protein
- Suppressor of Cytokine Signaling Proteins/drug effects
- Suppressor of Cytokine Signaling Proteins/metabolism
- Thiazolidinediones/chemistry
- Thiazolidinediones/pharmacology
- Thiazolidinediones/therapeutic use
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Affiliation(s)
- Kudret Tureyen
- Department of Neurological Surgery, University of Wisconsin, Madison, Wisconsin 53792, USA
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Ferrari MFR, Fior-Chadi DR. Chronic nicotine administration. Analysis of the development of hypertension and glutamatergic neurotransmission. Brain Res Bull 2006; 72:215-24. [PMID: 17452284 DOI: 10.1016/j.brainresbull.2006.09.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2006] [Revised: 09/13/2006] [Accepted: 09/15/2006] [Indexed: 11/27/2022]
Abstract
Among numerous neurotransmitters involved in central cardiovascular control, glutamate is one of the most studied transmitters that are related to nicotine considering its release and its postsynaptic regulation. However, there are no conclusive studies about nicotine effects on glutamatergic system and its relevance on hypertension development, which can help to understand the role of these two systems in that pathology. In this context, the objective of the present study is to evaluate the effects of systemic chronic nicotine exposure on hypertension development as well as the interaction between nicotine and the glutamatergic system in normotensive and neurogenic hypertensive rats. By means of high performance liquid chromatograph, immunohistochemistry, in situ hybridization and binding techniques, glutamatergic system was evaluated in SHR and Wistar Kyoto (WKY) rats treated with nicotine, delivered subcutaneously through nicotine pellets, for 8 weeks. The most important findings in this study were that (1) moderate doses of nicotine accelerated the onset and increased blood pressure in SHR but not in WKY rats, (2) the nicotine dosage and time of treatment employed did not affect body weight, (3) chronic nicotine treatment differentially affected glutamatergic system in normotensive and hypertensive rats, and (4) spontaneously hypertensive rats seem to be more sensitive to peripherally administered nicotine than Wistar Kyoto rats considering blood pressure and glutamatergic neurotransmission changes. In conclusion, we have demonstrated that a moderate dose of nicotine accelerates the onset and exacerbates hypertension in the SHR and that might be, at least in part, related to the modulation of glutamatergic neurotransmission.
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Affiliation(s)
- Merari F R Ferrari
- Department of Physiology, Institute of Biosciences, University of São Paulo, Rua do Matão, Travessa 14, n.321, Cidade Universitária-São Paulo, SP 05508-090, Brazil
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Díez-Freire C, Vázquez J, Correa de Adjounian MF, Ferrari MFR, Yuan L, Silver X, Torres R, Raizada MK. ACE2 gene transfer attenuates hypertension-linked pathophysiological changes in the SHR. Physiol Genomics 2006; 27:12-9. [PMID: 16788004 DOI: 10.1152/physiolgenomics.00312.2005] [Citation(s) in RCA: 153] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Recently discovered, angiotensin-converting enzyme-2 (ACE2) is an important therapeutic target in the control of cardiovascular diseases as a result of its proposed central role in the control of angiotensin peptides. Thus our objective in the present study was to determine whether ACE2 gene transfer could decrease high blood pressure (BP) and would improve cardiac dysfunctions induced by hypertension in the spontaneously hypertensive rat (SHR) model. Five-day-old SHR and normotensive WKY rats received a single intracardiac bolus injection of lentiviral vector containing either murine ACE2 (ACE2) or control enhanced green fluorescent protein (EGFP) genes. Systolic BP, cardiac functions, and perivascular fibrosis were evaluated 4 mo after ACE2 gene transduction. ACE2 gene transfer resulted in a significant attenuation of high BP in the SHR (149 +/- 2 mmHg in lenti-ACE2 vs. 180 +/- 9 mmHg in lenti-EGFP, P < 0.01). In contrast, no significant effect of lenti-ACE2 on BP of WKY rats was observed. Lenti-ACE2-treated SHR showed an 18% reduction in left ventricular wall thickness (1.52 +/- 0.04 vs. 1.86 +/- 0.04 mm in lenti-EGFP, P < 0.01). In addition, there was a 12% increase in left ventricular end diastolic and a 21% increase in end systolic diameters in lenti-ACE2-treated SHR. Finally, lenti-ACE2 treatment resulted in a significant attenuation of perivascular fibrosis in the SHR. In contrast, ACE2 gene transfer did not influence any of these parameters in WKY rats. These observations demonstrate that ACE2 overexpression exerts protective effects on high BP and cardiac pathophysiology induced by hypertension in the SHR.
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Affiliation(s)
- Carlos Díez-Freire
- Department of Physiology and Functional Genomics, College of Medicine, and Advanced Magnetic Resonance Imaging and Spectroscopy Facility at the McKnight Brain Institute, University of Florida, Gainesville, Florida 32610, USA
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Saavedra JM, Benicky J, Zhou J. Mechanisms of the Anti-Ischemic Effect of Angiotensin II AT( 1 ) Receptor Antagonists in the Brain. Cell Mol Neurobiol 2006; 26:1099-111. [PMID: 16636899 DOI: 10.1007/s10571-006-9009-0] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2005] [Accepted: 01/09/2006] [Indexed: 01/23/2023]
Abstract
1. Circulating and locally formed Angiotensin II regulates the cerebral circulation through stimulation of AT(1) receptors located in cerebrovascular endothelial cells and in brain centers controlling cerebrovascular flow. 2. The cerebrovascular autoregulation is designed to maintain a constant blood flow to the brain, by vasodilatation when blood pressure decreases and vasoconstriction when blood pressure increases. 3. During hypertension, there is a shift in the cerebrovascular autoregulation to the right, in the direction of higher blood pressures, as a consequence of decreased cerebrovascular compliance resulting from vasoconstriction and pathological growth. In hypertension, when perfusion pressure decreases as a consequence of blockade of a cerebral artery, reduced cerebrovascular compliance results in more frequent and more severe strokes with a larger area of injured tissue. 4. There is a cerebrovascular angiotensinergic overdrive in genetically hypertensive rats, manifested as an increased expression of cerebrovascular AT(1) receptors and increased activity of the brain Angiotensin II system. Excess AT(1) receptor stimulation is a main factor in the cerebrovascular pathological growth and decreased compliance, the alteration of the cerebrovascular eNOS/iNOS ratio, and in the inflammatory reaction characteristic of cerebral blood vessels in genetic hypertension. All these factors increase vulnerability to brain ischemia and stroke. 5. Sustained blockade of AT(1) receptors with peripheral and centrally active AT(1) receptor antagonists (ARBs) reverses the cerebrovascular pathological growth and inflammation, increases cerebrovascular compliance, restores the eNOS/iNOS ratio and decreases cerebrovascular inflammation. These effects result in a reduction of the vulnerability to brain ischemia, revealed, when an experimental stroke is produced, in protection of the blood flow in the zone of penumbra and substantial reduction in neuronal injury. 6. The protection against ischemia resulting is related to inhibition of the Renin-Angiotensin System and not directly related to the decrease in blood pressure produced by these compounds. A similar decrease in blood pressure as a result of the administration of beta-adrenergic receptor and calcium channel blockers does not protect from brain ischemia. 7. In addition, sustained AT(1) receptor inhibition enhances AT(2) receptor expression, associated with increased eNOS activity and NO formation followed by enhanced vasodilatation. Direct AT(1) inhibition and indirect AT(2) receptor stimulation are associated factors normalizing cerebrovascular compliance, reducing cerebrovascular inflammation and decreasing the vulnerability to brain ischemia.8. These results strongly suggest that inhibition of AT(1) receptors should be considered as a preventive therapeutic measure to protect the brain from ischemia, and as a possible novel therapy of inflammatory conditions of the brain.
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Affiliation(s)
- Juan M Saavedra
- Section on Pharmacology, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland, USA.
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Tayebati SK. Animal models of cognitive dysfunction. Mech Ageing Dev 2006; 127:100-8. [PMID: 16293295 DOI: 10.1016/j.mad.2005.09.026] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2004] [Revised: 02/04/2005] [Accepted: 09/15/2005] [Indexed: 10/25/2022]
Abstract
The increased life expectancy in industrialised countries in the last half century has also brought to a greater incidence of neurological disorders, including neurodegenerative diseases and developing in a rather long time. In this respect, Alzheimer's disease (AD), for the large incidence, and the dramatic loss of autonomy caused by its cognitive and behavioural symptoms represents one of the main challenges of modern medicine. Although AD is a typical human disease and probably includes several nosographic entities, the use of animal models may contribute to understand specific aspects of pathophysiology of the disease. The most widely used animal models are rodents and non-human primates. In this review different animal models characterised by impaired cognitive functions are analysed. None of the models available mimics exactly cognitive, behavioural, biochemical and histopathological abnormalities observed in neurological disorders characterised by cognitive impairment. However, partial reproduction of neuropathology and/or cognitive deficits of Alzheimer's disease (AD), vascular dementia and dementia occurring in Huntington's and Parkinson's diseases, or in other neurodegenerative disorders may represent a basis for understanding pathophysiological traits of these diseases and for contributing to their treatments.
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Affiliation(s)
- Seyed Khosrow Tayebati
- Anatomia Umana, Dipartimento di Medicina Sperimentale e Sanità Pubblica Università di Camerino, 62032 Camerino, Italy.
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Zhou J, Ando H, Macova M, Dou J, Saavedra JM. Angiotensin II AT1 receptor blockade abolishes brain microvascular inflammation and heat shock protein responses in hypertensive rats. J Cereb Blood Flow Metab 2005; 25:878-86. [PMID: 15729290 DOI: 10.1038/sj.jcbfm.9600082] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Endothelial dysfunction and inflammation enhance vulnerability to hypertensive brain damage. To explore the participation of Angiotensin II (Ang II) in the mechanism of vulnerability to cerebral ischemia during hypertension, we examined the expression of inflammatory factors and the heat shock protein (HSP) response in cerebral microvessels from spontaneously hypertensive rats and their normotensive controls, Wistar Kyoto rats. We treated animals with vehicle or the Ang II AT(1) receptor antagonist candesartan, 0.3 mg/kg/day, via subcutaneously implanted osmotic minipumps for 4 weeks. Spontaneously hypertensive rats expressed higher Angiotensin II AT(1) receptor protein and mRNA than normotensive controls. Candesartan decreased the macrophage infiltration and reversed the enhanced tumor necrosis factor-alpha and interleukin-1beta mRNA and nuclear factor-kappaB in microvessels in hypertensive rats. The transcription of many HSP family genes, including HSP60, HSP70 and HSP90, and heat shock factor-1 was higher in hypertensive rats and was downregulated by AT(1) receptor blockade. Our results suggest a proinflammatory action of Ang II through AT(1) receptor stimulation in cerebral microvessels during hypertension, and very potent antiinflammatory effects of the Ang II AT(1) receptor antagonist. These compounds might be considered as potential therapeutic agents against ischemic and inflammatory diseases of the brain.
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Affiliation(s)
- Jin Zhou
- Section on Pharmacology, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland 20892, USA.
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Hohnadel EJ, Hernandez CM, Gearhart DA, Terry AV. Effect of repeated nicotine exposure on high-affinity nicotinic acetylcholine receptor density in spontaneously hypertensive rats. Neurosci Lett 2005; 382:158-63. [PMID: 15911141 DOI: 10.1016/j.neulet.2005.03.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2005] [Revised: 02/22/2005] [Accepted: 03/04/2005] [Indexed: 11/26/2022]
Abstract
Spontaneously hypertensive rats (SHRs) are often used as a model of attention deficit hyperactivity disorder (ADHD) and to investigate the effects of hypertension on cognitive function. Further, they appear to have reduced numbers of central nicotinic acetylcholine receptors (nAChRs) and, therefore, may be useful to model certain aspects of Alzheimer's disease (AD) and other forms of dementia given that a decrease in nAChRs is thought to contribute to cognitive decline in these disorders. In the present study, based on reports that chronic nicotine exposure increases nAChRs in several mammalian models, we tested the hypothesis that repeated exposures to a relatively low dose of the alkaloid would ameliorate the receptor deficits in SHR. Thus, young-adult SHRs and age-matched Wistar-Kyoto (WKY) control rats were treated with either saline or nicotine twice a day for 14 days (total daily dose = 0.7 mg/kg nicotine base) and then sacrificed. Quantitative receptor autoradiography with [125I]-IPH, an epibatidine analog, revealed: (1) that high-affinity nAChRs were higher in saline-treated WKY (control) rats compared to saline-treated SHRs in 18 of the 19 brain region measured, although statistically different only in the mediodorsal thalamic nuclei, (2) that nicotine significantly increased nAChR binding in WKY rats in six brain areas including cortical regions and the anterior thalamic nucleus, (3) that there were no cases where nicotine significantly increased nAChR binding in SHRs. These results indicate that subjects deficient in nAChRs may be less sensitive to nAChR upregulation with nicotine than normal subjects and require higher doses or longer periods of exposure.
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Affiliation(s)
- Elizabeth J Hohnadel
- Program in Clinical and Experimental Therapeutics, University of Georgia College of Pharmacy (Augusta Campus), Medical College of Georgia, Augusta, GA 30912, USA
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Gutermuth J, Ollert M, Ring J, Behrendt H, Jakob T. Mouse Models of Atopic Eczema Critically Evaluated. Int Arch Allergy Immunol 2004; 135:262-76. [PMID: 15542938 DOI: 10.1159/000082099] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Atopic eczema (AE) is a chronic relapsing inflammatory skin disorder with increasing prevalence in Western societies. Even though we have made considerable progress in understanding the cellular and molecular nature of cutaneous inflammation, the precise pathomechanisms of AE still remain elusive. Experimental animal models are indispensable tools to study the pathogenic mechanisms and to test novel therapeutic approaches in vivo. For AE a considerable number of mouse models have been proposed and have been used to study specific aspects of the disease, such as genetics, skin barrier defects, immune deviations, bacteria-host interactions or the role of cytokines or chemokines in the inflammatory process. While some models closely resemble human AE, others appear to reflect only specific aspects of the disease. Here we review the currently available mouse models of AE in light of the novel World Allergy Organization classification of eczematous skin diseases and evaluate them according to their clinical, histopathological and immunological findings. The pathogenetic analogies between mice and men will be discussed.
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Affiliation(s)
- Jan Gutermuth
- Division of Environmental Dermatology and Allergy GSF/TUM, GSF National Research Center for Environment and Health and ZAUM Center for Allergy and Environment, Technical University, Munich, Germany
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Vega E, Gómez-Villalobos MDJ, Flores G. Alteration in dendritic morphology of pyramidal neurons from the prefrontal cortex of rats with renovascular hypertension. Brain Res 2004; 1021:112-8. [PMID: 15328038 DOI: 10.1016/j.brainres.2004.06.042] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/27/2004] [Indexed: 10/26/2022]
Abstract
We have studied, in the rat, the dendritic morphological changes of the pyramidal neurons of the medial part of the prefrontal cortex induced by the chronic effect of high blood pressure. Renovascular hypertension was induced using a silver clip on the renal artery by surgery. The morphology of the pyramidal neurons from the medial part of the prefrontal cortex was investigated in these animals. The blood pressure was measured to confirm the increase in the arterial blood pressure. After 16 weeks of increase in the arterial blood pressure, the animals were sacrificed by overdoses of sodium pentobarbital and perfused intracardially with a 0.9% saline solution. The brains were removed, processed by the Golgi-Cox stain method and analyzed by the Sholl method. The dendritic morphology clearly showed that the hypertensive animals had an increase (32%) in the dendritic length of the pyramidal cells with a decrease (50%) in the density of dendritic spines when compared with sham animals. The branch-order analysis showed that the animals with hypertension exhibit more dendritic arborization at the level of the first to fourth branch order. This result suggests that renovascular hypertension may in part affect the dendritic morphology in this limbic structure, which may implicate cognitive impairment in hypertensive patients.
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Affiliation(s)
- Elenia Vega
- Escuela de Biología, Universidad Autónoma de Puebla, Puebla, México
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Ueno M, Sakamoto H, Liao YJ, Onodera M, Huang CL, Miyanaka H, Nakagawa T. Blood-brain barrier disruption in the hypothalamus of young adult spontaneously hypertensive rats. Histochem Cell Biol 2004; 122:131-7. [PMID: 15258771 DOI: 10.1007/s00418-004-0684-y] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/22/2004] [Indexed: 12/12/2022]
Abstract
Vascular permeability and endothelial glycocalyx were examined in young adult spontaneously hypertensive rats (SHR), stroke-prone SHR (SHRSP), and Wistar Kyoto rats (WKY) as a control, in order to determine earlier changes in the blood-brain barrier (BBB) in the hypothalamus in chronic hypertension. These rats were injected with horseradish peroxidase (HRP) as an indicator of vascular permeability. Brain slices were developed with a chromogen and further examined with cationized ferritin, a marker for evaluating glycocalyx. Staining for HRP was seen around vessels in the hypothalamus of SHR and SHRSP, but was scarce in WKY. The reaction product of HRP appeared in the abluminal pits of endothelial cells and within the basal lamina of arterioles, showing increased vascular permeability in the hypothalamus of SHR and SHRSP, whereas there were no leaky vessels in the frontal cortex of SHR and SHRSP, or in both areas of WKY. The number of cationized ferritin particles binding to the capillary endothelial cells was decreased in the hypothalamus of SHR and SHRSP, while the number decreased in the frontal cortex of SHRSP, compared with those in WKY. Cationized ferritin binding was preserved in some leaky arterioles, while it was scarce or disappeared in other leaky vessels. These findings suggest that BBB disruption occurs in the hypothalamus of 3-month-old SHR and SHRSP, and that endothelial glycocalyx is markedly damaged there without a close relationship to the early changes in the BBB.
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Affiliation(s)
- Masaki Ueno
- Department of Pathology and Host Defense, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kita-gun, 761-0793, Kagawa, Japan. ,jp
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Affiliation(s)
- Nancy Futrell
- Intermountain Stroke Center, 5292 College Drive, Suite 204, Salt Lake City, UT 84123, USA.
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Schipper L, Spee B, Rothuizen J, Woutersen-van Nijnanten F, Fink-Gremmels J. Characterisation of 11β-hydroxysteroid dehydrogenases in feline kidney and liver. Biochim Biophys Acta Mol Basis Dis 2004; 1688:68-77. [PMID: 14732482 DOI: 10.1016/j.bbadis.2003.11.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
11 Beta-hydroxysteroid dehydrogenases type 1 and 2 (11 beta-HSD1 and 11 beta-HSD2) are microsomal enzymes responsible for the interconversion of cortisol into the inactive form cortisone and vice versa. 11 beta-HSD1 is mainly present in the liver, and has predominantly reductase activity although its function has not yet been elucidated. 11 beta-HSD2, present in mineralocorticoid target tissues such as the kidney, converts cortisol into cortisone. Reduced activity due to inhibition or mutations of 11 beta-HSD2 leads to hypertension and hypokalemia resulting in the Apparent Mineralocorticoid Excess Syndrome (AMES). Like humans, cats are highly susceptible for hypertension. As large species differences exist with respect to the kinetic parameters (K(m) and V(max)) and amino acid sequences of both enzymes, we determined these characteristics in the cat. Both enzyme types were found in the kidneys. 11 beta-HSD1 in the feline kidney showed bidirectional activity with predominantly dehydrogenase activity (dehydrogenase: K(m) 1959+/-797 nM, V(max) 766+/-88 pmol/mg*min; reductase: K(m) 778+/-136 nM, V(max) 112+/-4 pmol/mg*min). 11 beta-HSD2 represents a unidirectional dehydrogenase with a higher substrate affinity (K(m) 184+/-24 nM, V(max) 74+/-3 pmol/mg*min). In the liver, only 11 beta-HSD1 is detected exerting reductase activity (K(m) 10462 nM, V(max) 840 pmol/mg*min). Sequence analysis of conserved parts of 11 beta-HSD1 and 11 beta-HSD2 revealed the highest homology of the feline enzymes with the correspondent enzymes found in man. This suggests that the cat may serve as a suitable model species for studies directed to the pathogenesis and treatment of human diseases like AMES and hypertension.
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Affiliation(s)
- L Schipper
- Department of Veterinary Pharmacy, Pharmacology and Toxicology, Faculty of Veterinary Medicine, University Utrecht, P.O. Box 80.152, 3508 TD Utrecht, The Netherlands
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