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Jung YH, Lee HY, Lee BK, Choi BK, Kim TH, Kim JW, Kim HC, Kim HJ, Jeung KW. Feasibility of Magnetic Resonance-Based Conductivity Imaging as a Tool to Estimate the Severity of Hypoxic-Ischemic Brain Injury in the First Hours After Cardiac Arrest. Neurocrit Care 2024; 40:538-550. [PMID: 37353670 DOI: 10.1007/s12028-023-01776-4] [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: 01/25/2023] [Accepted: 06/05/2023] [Indexed: 06/25/2023]
Abstract
BACKGROUND Early identification of the severity of hypoxic-ischemic brain injury (HIBI) after cardiac arrest can be used to help plan appropriate subsequent therapy. We evaluated whether conductivity of cerebral tissue measured using magnetic resonance-based conductivity imaging (MRCI), which provides contrast derived from the concentration and mobility of ions within the imaged tissue, can reflect the severity of HIBI in the early hours after cardiac arrest. METHODS Fourteen minipigs were resuscitated after 5 min or 12 min of untreated cardiac arrest. MRCI was performed at baseline and at 1 h and 3.5 h after return of spontaneous circulation (ROSC). RESULTS In both groups, the conductivity of cerebral tissue significantly increased at 1 h after ROSC compared with that at baseline (P = 0.031 and 0.016 in the 5-min and 12-min groups, respectively). The increase was greater in the 12-min group, resulting in significantly higher conductivity values in the 12-min group (P = 0.030). At 3.5 h after ROSC, the conductivity of cerebral tissue in the 12-min group remained increased (P = 0.022), whereas that in the 5-min group returned to its baseline level. CONCLUSIONS The conductivity of cerebral tissue was increased in the first hours after ROSC, and the increase was more prominent and lasted longer in the 12-min group than in the 5-min group. Our findings suggest the promising potential of MRCI as a tool to estimate the severity of HIBI in the early hours after cardiac arrest.
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Affiliation(s)
- Yong Hun Jung
- Department of Emergency Medicine, Chonnam National University Hospital, 42 Jebong-ro, Donggu, Gwangju, 61469, Republic of Korea
- Department of Emergency Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Hyoung Youn Lee
- Trauma Center, Chonnam National University Hospital, Gwangju, Republic of Korea
| | - Byung Kook Lee
- Department of Emergency Medicine, Chonnam National University Hospital, 42 Jebong-ro, Donggu, Gwangju, 61469, Republic of Korea
- Department of Emergency Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Bup Kyung Choi
- Medical Science Research Institute, Kyung Hee University Hospital, Seoul, Republic of Korea
| | - Tae-Hoon Kim
- Medical Convergence Research Center, Wonkwang University, Iksan, Republic of Korea
| | - Jin Woong Kim
- Department of Radiology, Chosun University Hospital, Gwangju, Republic of Korea
| | - Hyun Chul Kim
- Department of Radiology, Chosun University Hospital, Gwangju, Republic of Korea
| | - Hyung Joong Kim
- Medical Science Research Institute, Kyung Hee University Hospital, Seoul, Republic of Korea
| | - Kyung Woon Jeung
- Department of Emergency Medicine, Chonnam National University Hospital, 42 Jebong-ro, Donggu, Gwangju, 61469, Republic of Korea.
- Department of Emergency Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea.
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Lee JY, Lee KM, Kim HG, Woo HG, Lee JS, Kim EJ. The Clinical Significance of the Hyperintense Acute Reperfusion Marker Sign in Subacute Infarction Patients. Diagnostics (Basel) 2021; 11:diagnostics11112161. [PMID: 34829508 PMCID: PMC8625489 DOI: 10.3390/diagnostics11112161] [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: 09/29/2021] [Revised: 11/15/2021] [Accepted: 11/17/2021] [Indexed: 11/16/2022] Open
Abstract
Purpose: The hyperintense acute reperfusion marker (HARM) is characterized by the delayed enhancement of the subarachnoid or subpial space observed on postcontrast fluid-attenuated inversion recovery (FLAIR) images, and is considered a cerebral reperfusion marker for various brain disorders, including infarction. In this study, we evaluated the cerebral distribution patterns of HARM for discriminating between an enhancing subacute infarction and an enhancing mass located in the cortex and subcortical white matter. Materials and methods: We analyzed consecutive patients who experienced a subacute ischemic stroke, were hospitalized, and underwent conventional brain magnetic resonance imaging including postcontrast FLAIR within 14 days from symptom onset, as well as those who had lesions corresponding to a clinical sign detected by diffusion-weighted imaging and postcontrast T1-weighted imaging between May 2019 and May 2021. A total of 199 patients were included in the study. Of them, 94 were finally included in the subacute infarction group. During the same period, 76 enhancing masses located in the cortex or subcortical white matter, which were subcategorized as metastasis, malignant glioma, and lymphoma, were analyzed. We analyzed the overall incidence of HARM in subacute ischemic stroke cases, and compared the enhancement patterns between cortical infarctions and cortical masses. Results: Among 94 patients with subacute stroke, 78 patients (83%) presented HARM, and among 76 patients with subcortical masses, 48 patients (63%) presented peripheral rim enhancement. Of 170 subcortical enhancing lesions, 88 (51.8%) showed HARM, and 78 (88.6%) were determined to be subacute infarction. Among 94 patients with subacute stroke, 48 patients (51%) had diffusion restrictions, and HARM was found in 39 patients (81.2%). Of the 46 patients (49%) without diffusion restriction, 39 patients (84.8%) showed HARM. Conclusions: The presence of HARM was significantly associated with subacute infarctions. For the masses, a peripheral rim enhancement pattern was observed around the mass rather than the cerebral sulci on postcontrast FLAIR.
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Affiliation(s)
- Ji Young Lee
- Department of Medicine, Graduate School, Kyung Hee University, #23 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Korea;
| | - Kyung Mi Lee
- Department of Radiology, College of Medicine, Kyung Hee University Hospital, Kyung Hee University, #23 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Korea; (H.-G.K.); (E.J.K.)
- Correspondence: ; Tel.: +82-2-958-8623; Fax: +82-2-968-0787
| | - Hyug-Gi Kim
- Department of Radiology, College of Medicine, Kyung Hee University Hospital, Kyung Hee University, #23 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Korea; (H.-G.K.); (E.J.K.)
| | - Ho-Geol Woo
- Department of Neurology, College of Medicine, Kyung Hee University Hospital, Kyung Hee University, #23 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Korea; (H.-G.W.); (J.S.L.)
| | - Jin San Lee
- Department of Neurology, College of Medicine, Kyung Hee University Hospital, Kyung Hee University, #23 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Korea; (H.-G.W.); (J.S.L.)
| | - Eui Jong Kim
- Department of Radiology, College of Medicine, Kyung Hee University Hospital, Kyung Hee University, #23 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Korea; (H.-G.K.); (E.J.K.)
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Abstract
Our brains consist of 80% water, which is continuously shifted between different compartments and cell types during physiological and pathophysiological processes. Disturbances in brain water homeostasis occur with pathologies such as brain oedema and hydrocephalus, in which fluid accumulation leads to elevated intracranial pressure. Targeted pharmacological treatments do not exist for these conditions owing to our incomplete understanding of the molecular mechanisms governing brain water transport. Historically, the transmembrane movement of brain water was assumed to occur as passive movement of water along the osmotic gradient, greatly accelerated by water channels termed aquaporins. Although aquaporins govern the majority of fluid handling in the kidney, they do not suffice to explain the overall brain water movement: either they are not present in the membranes across which water flows or they appear not to be required for the observed flow of water. Notably, brain fluid can be secreted against an osmotic gradient, suggesting that conventional osmotic water flow may not describe all transmembrane fluid transport in the brain. The cotransport of water is an unconventional molecular mechanism that is introduced in this Review as a missing link to bridge the gap in our understanding of cellular and barrier brain water transport.
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Affiliation(s)
- Nanna MacAulay
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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4
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Association between ion shift index and prognosis in severe trauma patients without isolated head injury. Injury 2021; 52:1151-1157. [PMID: 33745698 DOI: 10.1016/j.injury.2021.03.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 02/13/2021] [Accepted: 03/01/2021] [Indexed: 02/02/2023]
Abstract
INTRODUCTION This study aimed to investigate the ion shift index (ISI) as a prognostic factor of severe trauma. We hypothesized that the initial ISI measured in the emergency department (ED) is associated with discharge survival in severe non-isolated head injury (IHI) patients. MATERIALS AND METHODS This retrospective observational study included severe trauma patients with available medical records from January 2017 to December 2018 but excluded those with IHI. Logistic regression analysis was conducted to identify the risk factors for mortality in non-IHI patients, and adjustments were performed for relevant covariates. An area under the receiver operating characteristics curve (AUROC) analysis was performed to examine the primary outcome of our study, which was mortality at hospital discharge in severe non-IHI trauma patients. RESULTS Of the 483 severe non-IHI trauma patients included in the study, 86 patients (17.8 %) died. The multiple logistic regression analysis demonstrated ISI (odds ratio [OR], 2.300; 95% CI, 1.183-4.470) was significantly associated with mortality in the non-IHI group. Additionally, trauma and injury severity score (TRISS; OR, 0.538; 95% CI, 0.447-0.649), lactate (OR, 1.410; 95% CI, 1.252-1.588), creatinine (OR, 1.554; 95% CI, 1.221-1.979), and activated partial thromboplastin time (aPTT; OR, 1.050; 95% CI, 1.021-1.080) were independently associated with mortality at hospital discharge. The AUROC values for TRISS, lactate, aPTT, creatinine, and ISI were as follows: 0.892 (95% CI, 0.861-0.918), 0.838 (95% CI, 0.803-0.870), 0.754 (95% CI, 0.712-0.792), 0.650 (95% CI, 0.606-0.693), and 0.848 (95% CI, 0.813-0.879), respectively. The AUROC for the multiple logistic regression model with ISI was 0.942 (95% CI, 0.917-0.962). In a model in which TRISS was omitted, the addition of ISI to other predictors significantly improved the AUROC to 0.900 (95% CI, 0.869-0.925) (p=0.039). CONCLUSION The initial ISI in the ED after trauma was associated with mortality in severe non-IHI trauma patients. In conjunction with other prognostic indicators, it could be used as an early prognostic marker, particularly if TRISS is unavailable.
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Ion shift index as a promising prognostic indicator in adult patients resuscitated from cardiac arrest. Resuscitation 2019; 137:116-123. [DOI: 10.1016/j.resuscitation.2019.02.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 02/05/2019] [Accepted: 02/11/2019] [Indexed: 11/21/2022]
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Bonde L, Boedtkjer E. Extracellular acidosis and very low [Na + ] inhibit NBCn1- and NHE1-mediated net acid extrusion from mouse vascular smooth muscle cells. Acta Physiol (Oxf) 2017; 221:129-141. [PMID: 28319329 DOI: 10.1111/apha.12877] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 02/20/2017] [Accepted: 03/14/2017] [Indexed: 12/28/2022]
Abstract
AIM The electroneutral Na+ , HCO3- cotransporter NBCn1 and Na+ /H+ exchanger NHE1 regulate acid-base balance in vascular smooth muscle cells (VSMCs) and modify artery function and structure. Pathological conditions - notably ischaemia - can dramatically perturb intracellular (i) and extracellular (o) pH and [Na+ ]. We examined effects of low [Na+ ]o and pHo on NBCn1 and NHE1 activity in VSMCs of small arteries. METHODS We measured pHi by 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein-based fluorescence microscopy of mouse mesenteric arteries and induced intracellular acidification by NH4+ prepulse technique. RESULTS NBCn1 activity - defined as Na+ -dependent, amiloride-insensitive net base uptake with CO2 /HCO3- present - was inhibited equally when pHo decreased from 7.4 (22 mm HCO3-/5% CO2 ) by metabolic (pHo 7.1/11 mm HCO3-: 22 ± 8%; pHo 6.8/5.5 mm HCO3-: 61 ± 7%) or respiratory (pHo 7.1/10% CO2 : 35 ± 11%; pHo 6.8/20% CO2 : 56 ± 7%) acidosis. Extracellular acidosis more prominently inhibited NHE1 activity - defined as Na+ -dependent net acid extrusion without CO2 /HCO3- present - at both pHo 7.1 (45 ± 9%) and 6.8 (85 ± 5%). Independently of pHo , lowering [Na+ ]o from 140 to 70 mm reduced NBCn1 and NHE1 activity <20% whereas transport activities declined markedly (25-50%) when [Na+ ]o was reduced to 35 mm. Steady-state pHi decreased more during respiratory (ΔpHi /ΔpHo = 71 ± 4%) than metabolic (ΔpHi /ΔpHo = 30 ± 7%) acidosis. CONCLUSION Extracellular acidification inhibits NBCn1 and NHE1 activity in VSMCs. NBCn1 is equivalently inhibited when pCO2 is raised or [HCO3-]o decreased. Lowering [Na+ ]o inhibits NBCn1 and NHE1 markedly only below the typical physiological and pathophysiological range. We propose that inhibition of Na+ -dependent net acid extrusion at low pHo protects against cellular Na+ overload at the cost of intracellular acidification.
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Affiliation(s)
- L. Bonde
- Department of Biomedicine; Aarhus University; Aarhus Denmark
| | - E. Boedtkjer
- Department of Biomedicine; Aarhus University; Aarhus Denmark
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7
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Nilsson H. In defence of pH. Acta Physiol (Oxf) 2017; 221:90-92. [PMID: 28429884 DOI: 10.1111/apha.12888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- H Nilsson
- Department of Physiology, Institute of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden
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8
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Hartings JA, Shuttleworth CW, Kirov SA, Ayata C, Hinzman JM, Foreman B, Andrew RD, Boutelle MG, Brennan KC, Carlson AP, Dahlem MA, Drenckhahn C, Dohmen C, Fabricius M, Farkas E, Feuerstein D, Graf R, Helbok R, Lauritzen M, Major S, Oliveira-Ferreira AI, Richter F, Rosenthal ES, Sakowitz OW, Sánchez-Porras R, Santos E, Schöll M, Strong AJ, Urbach A, Westover MB, Winkler MK, Witte OW, Woitzik J, Dreier JP. The continuum of spreading depolarizations in acute cortical lesion development: Examining Leão's legacy. J Cereb Blood Flow Metab 2017; 37:1571-1594. [PMID: 27328690 PMCID: PMC5435288 DOI: 10.1177/0271678x16654495] [Citation(s) in RCA: 256] [Impact Index Per Article: 36.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A modern understanding of how cerebral cortical lesions develop after acute brain injury is based on Aristides Leão's historic discoveries of spreading depression and asphyxial/anoxic depolarization. Treated as separate entities for decades, we now appreciate that these events define a continuum of spreading mass depolarizations, a concept that is central to understanding their pathologic effects. Within minutes of acute severe ischemia, the onset of persistent depolarization triggers the breakdown of ion homeostasis and development of cytotoxic edema. These persistent changes are diagnosed as diffusion restriction in magnetic resonance imaging and define the ischemic core. In delayed lesion growth, transient spreading depolarizations arise spontaneously in the ischemic penumbra and induce further persistent depolarization and excitotoxic damage, progressively expanding the ischemic core. The causal role of these waves in lesion development has been proven by real-time monitoring of electrophysiology, blood flow, and cytotoxic edema. The spreading depolarization continuum further applies to other models of acute cortical lesions, suggesting that it is a universal principle of cortical lesion development. These pathophysiologic concepts establish a working hypothesis for translation to human disease, where complex patterns of depolarizations are observed in acute brain injury and appear to mediate and signal ongoing secondary damage.
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Affiliation(s)
- Jed A Hartings
- 1 Department of Neurosurgery, University of Cincinnati College of Medicine, Cincinnati, OH, USA.,2 Mayfield Clinic, Cincinnati, OH, USA
| | - C William Shuttleworth
- 3 Department of Neuroscience, University of New Mexico School of Medicine, Albuquerque, NM, USA
| | - Sergei A Kirov
- 4 Department of Neurosurgery and Brain and Behavior Discovery Institute, Medical College of Georgia, Augusta, GA, USA
| | - Cenk Ayata
- 5 Neurovascular Research Unit, Department of Radiology, and Stroke Service and Neuroscience Intensive Care Unit, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Jason M Hinzman
- 1 Department of Neurosurgery, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Brandon Foreman
- 6 Department of Neurology and Rehabilitation Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - R David Andrew
- 7 Department of Biomedical & Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | - Martyn G Boutelle
- 8 Department of Bioengineering, Imperial College London, London, United Kingdom
| | - K C Brennan
- 9 Department of Neurology, University of Utah, Salt Lake City, UT, USA.,10 Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT, USA
| | - Andrew P Carlson
- 11 Department of Neurosurgery, University of New Mexico School of Medicine, Albuquerque, NM, USA
| | - Markus A Dahlem
- 12 Department of Physics, Humboldt University of Berlin, Berlin, Germany
| | | | - Christian Dohmen
- 14 Department of Neurology, University of Cologne, Cologne, Germany
| | - Martin Fabricius
- 15 Department of Clinical Neurophysiology, Rigshospitalet, Glostrup, Denmark
| | - Eszter Farkas
- 16 Department of Medical Physics and Informatics, Faculty of Medicine, and Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Delphine Feuerstein
- 17 Multimodal Imaging of Brain Metabolism, Max-Planck-Institute for Metabolism Research, Cologne, Germany
| | - Rudolf Graf
- 17 Multimodal Imaging of Brain Metabolism, Max-Planck-Institute for Metabolism Research, Cologne, Germany
| | - Raimund Helbok
- 18 Medical University of Innsbruck, Department of Neurology, Neurocritical Care Unit, Innsbruck, Austria
| | - Martin Lauritzen
- 15 Department of Clinical Neurophysiology, Rigshospitalet, Glostrup, Denmark.,19 Department of Neuroscience and Pharmacology and Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark
| | - Sebastian Major
- 13 Department of Neurology, Charité University Medicine, Berlin, Germany.,20 Center for Stroke Research Berlin, Charité University Medicine, Berlin, Germany.,21 Department of Experimental Neurology, Charité University Medicine, Berlin, Germany
| | - Ana I Oliveira-Ferreira
- 20 Center for Stroke Research Berlin, Charité University Medicine, Berlin, Germany.,21 Department of Experimental Neurology, Charité University Medicine, Berlin, Germany
| | - Frank Richter
- 22 Institute of Physiology/Neurophysiology, Jena University Hospital, Jena, Germany
| | - Eric S Rosenthal
- 5 Neurovascular Research Unit, Department of Radiology, and Stroke Service and Neuroscience Intensive Care Unit, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Oliver W Sakowitz
- 23 Department of Neurosurgery, Klinikum Ludwigsburg, Ludwigsburg, Germany.,24 Department of Neurosurgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Renán Sánchez-Porras
- 24 Department of Neurosurgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Edgar Santos
- 24 Department of Neurosurgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Michael Schöll
- 24 Department of Neurosurgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Anthony J Strong
- 25 Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London
| | - Anja Urbach
- 26 Hans Berger Department of Neurology, Jena University Hospital, Jena, Germany
| | - M Brandon Westover
- 5 Neurovascular Research Unit, Department of Radiology, and Stroke Service and Neuroscience Intensive Care Unit, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Maren Kl Winkler
- 20 Center for Stroke Research Berlin, Charité University Medicine, Berlin, Germany
| | - Otto W Witte
- 26 Hans Berger Department of Neurology, Jena University Hospital, Jena, Germany.,27 Brain Imaging Center, Jena University Hospital, Jena, Germany
| | - Johannes Woitzik
- 20 Center for Stroke Research Berlin, Charité University Medicine, Berlin, Germany.,28 Department of Neurosurgery, Charité University Medicine, Berlin, Germany
| | - Jens P Dreier
- 13 Department of Neurology, Charité University Medicine, Berlin, Germany.,20 Center for Stroke Research Berlin, Charité University Medicine, Berlin, Germany.,21 Department of Experimental Neurology, Charité University Medicine, Berlin, Germany
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Hsu Y, Tran M, Linninger AA. Dynamic regulation of aquaporin-4 water channels in neurological disorders. Croat Med J 2016; 56:401-21. [PMID: 26526878 PMCID: PMC4655926 DOI: 10.3325/cmj.2015.56.401] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Aquaporin-4 water channels play a central role in brain water regulation in neurological disorders. Aquaporin-4 is abundantly expressed at the astroglial endfeet facing the cerebral vasculature and the pial membrane, and both its expression level and subcellular localization significantly influence brain water transport. However, measurements of aquaporin-4 levels in animal models of brain injury often report opposite trends of change at the injury core and the penumbra. Furthermore, aquaporin-4 channels play a beneficial role in brain water clearance in vasogenic edema, but a detrimental role in cytotoxic edema and exacerbate cell swelling. In light of current evidence, we still do not have a complete understanding of the role of aquaporin-4 in brain water transport. In this review, we propose that the regulatory mechanisms of aquaporin-4 at the transcriptional, translational, and post-translational levels jointly regulate water permeability in the short and long time scale after injury. Furthermore, in order to understand why aquaporin-4 channels play opposing roles in cytotoxic and vasogenic edema, we discuss experimental evidence on the dynamically changing osmotic gradients between blood, extracellular space, and the cytosol during the formation of cytotoxic and vasogenic edema. We conclude with an emerging picture of the distinct osmotic environments in cytotoxic and vasogenic edema, and propose that the directions of aquaporin-4-mediated water clearance in these two types of edema are distinct. The difference in water clearance pathways may provide an explanation for the conflicting observations of the roles of aquaporin-4 in edema resolution.
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Affiliation(s)
| | | | - Andreas A Linninger
- Andreas Linninger, 851 S Morgan St., SEO 218, MC 063, Chicago, IL 60607, USA,
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10
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Stöber F, Baldauf K, Ziabreva I, Harhausen D, Zille M, Neubert J, Reymann KG, Scheich H, Dirnagl U, Schröder UH, Wunder A, Goldschmidt J. Single-cell resolution mapping of neuronal damage in acute focal cerebral ischemia using thallium autometallography. J Cereb Blood Flow Metab 2014; 34:144-52. [PMID: 24129748 PMCID: PMC3887354 DOI: 10.1038/jcbfm.2013.177] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 08/16/2013] [Accepted: 09/06/2013] [Indexed: 11/26/2022]
Abstract
Neuronal damage shortly after onset or after brief episodes of cerebral ischemia has remained difficult to assess with clinical and preclinical imaging techniques as well as with microscopical methods. We here show, in rodent models of middle cerebral artery occlusion (MCAO), that neuronal damage in acute focal cerebral ischemia can be mapped with single-cell resolution using thallium autometallography (TlAMG), a histochemical technique for the detection of the K(+)-probe thallium (Tl(+)) in the brain. We intravenously injected rats and mice with thallium diethyldithiocarbamate (TlDDC), a lipophilic chelate complex that releases Tl(+) after crossing the blood-brain barrier. We found, within the territories of the affected arteries, areas of markedly reduced neuronal Tl(+) uptake in all animals at all time points studied ranging from 15 minutes to 24 hours after MCAO. In large lesions at early time points, areas with neuronal and astrocytic Tl(+) uptake below thresholds of detection were surrounded by putative penumbral zones with preserved but diminished Tl(+) uptake. At 24 hours, the areas of reduced Tl(+)uptake matched with areas delineated by established markers of neuronal damage. The results suggest the use of (201)TlDDC for preclinical and clinical single-photon emission computed tomography (SPECT) imaging of hyperacute alterations in brain K(+) metabolism and prediction of tissue viability in cerebral ischemia.
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Affiliation(s)
- Franziska Stöber
- 1] Department of Experimental Neurology, Center for Stroke Research Berlin (CSB), Charité-University Medicine Berlin, Berlin, Germany [2] Department of Auditory Learning and Speech, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Kathrin Baldauf
- 1] Project Group Neuropharmacology, Leibniz Institute for Neurobiology, Magdeburg, Germany [2] German Center for Neurodegenerative Diseases (DZNE), Partner site Magdeburg, Magdeburg, Germany
| | - Iryna Ziabreva
- 1] Project Group Neuropharmacology, Leibniz Institute for Neurobiology, Magdeburg, Germany [2] Research Institute for Applied Neurosciences (FAN) GmbH, Magdeburg, Germany [3] Institute of Health & Society, Newcastle University, Newcastle upon Tyne, UK
| | - Denise Harhausen
- Department of Experimental Neurology, Center for Stroke Research Berlin (CSB), Charité-University Medicine Berlin, Berlin, Germany
| | - Marietta Zille
- Department of Experimental Neurology, Center for Stroke Research Berlin (CSB), Charité-University Medicine Berlin, Berlin, Germany
| | - Jenni Neubert
- 1] Department of Auditory Learning and Speech, Leibniz Institute for Neurobiology, Magdeburg, Germany [2] Institute of Cell Biology and Neurobiology, Charité-University Medicine Berlin, Berlin, Germany
| | - Klaus G Reymann
- 1] Project Group Neuropharmacology, Leibniz Institute for Neurobiology, Magdeburg, Germany [2] German Center for Neurodegenerative Diseases (DZNE), Partner site Magdeburg, Magdeburg, Germany
| | - Henning Scheich
- 1] Department of Auditory Learning and Speech, Leibniz Institute for Neurobiology, Magdeburg, Germany [2] German Center for Neurodegenerative Diseases (DZNE), Partner site Magdeburg, Magdeburg, Germany [3] Center for Behavioral Brain Sciences, Magdeburg, Germany
| | - Ulrich Dirnagl
- 1] Department of Experimental Neurology, Center for Stroke Research Berlin (CSB), Charité-University Medicine Berlin, Berlin, Germany [2] German Centre for Neurodegenerative Diseases (DZNE), Partner site Berlin, Berlin, Germany
| | - Ulrich H Schröder
- 1] Project Group Neuropharmacology, Leibniz Institute for Neurobiology, Magdeburg, Germany [2] Research Institute for Applied Neurosciences (FAN) GmbH, Magdeburg, Germany
| | - Andreas Wunder
- Department of Experimental Neurology, Center for Stroke Research Berlin (CSB), Charité-University Medicine Berlin, Berlin, Germany
| | - Jürgen Goldschmidt
- 1] Department of Auditory Learning and Speech, Leibniz Institute for Neurobiology, Magdeburg, Germany [2] Clinic for Neurology, Otto-von-Guericke University, Magdeburg, Germany
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11
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Pathophysiological Role of Global Cerebral Ischemia following Subarachnoid Hemorrhage: The Current Experimental Evidence. Stroke Res Treat 2013; 2013:651958. [PMID: 23844316 PMCID: PMC3694494 DOI: 10.1155/2013/651958] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 04/29/2013] [Indexed: 11/24/2022] Open
Abstract
Subarachnoid hemorrhage (SAH) is the subtype of stroke with one of the highest mortality rates and the least well-understood pathophysiologies. One of the very early events which may occur after SAH is a significant decrease of cerebral perfusion pressure (CPP) caused by the excessive increase of intracranial pressure during the initial bleeding. A severely decreased CPP results in global cerebral ischemia, an event also occurring after cardiac arrest. The aim of the current paper is to review the pathophysiological events occurring in experimental models of SAH and global cerebral ischemia and to evaluate the contribution and the importance of global cerebral ischemia for the pathophysiology of SAH.
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Schneider A, Albertsmeier M, Böttiger BW, Teschendorf P. [Post-resuscitation syndrome. Role of inflammation after cardiac arrest]. Anaesthesist 2012; 61:424-36. [PMID: 22576987 DOI: 10.1007/s00101-012-2002-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Cardiac arrest with subsequent cardiopulmonary resuscitation causes an ischemic reperfusion syndrome of the whole body resulting in localized damage of particularly sensitive organs, such as the brain and heart, together with systemic sequelae. The main factor is a generalized activation of inflammatory reactions resulting in symptoms similar in many aspects to those of sepsis. Systemic inflammation strengthens organ damage due to disorders in the macrocirculation and microcirculation due to metabolic imbalance as well as the effects of direct leukocyte transmitted tissue destruction. The current article gives an overview on the role of inflammation following cardiac arrest and presents in detail the underlying mechanisms, the clinical symptoms and possible therapeutic approaches.
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Affiliation(s)
- A Schneider
- Klinik für Anästhesiologie und Operative Intensivmedizin, Universitätsklinikum Köln, Kerpener Str. 62, 50937 Köln, Deutschland.
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13
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Boada FE, Qian Y, Nemoto E, Jovin T, Jungreis C, Jones SC, Weimer J, Lee V. Sodium MRI and the assessment of irreversible tissue damage during hyper-acute stroke. Transl Stroke Res 2012; 3:236-45. [PMID: 24323779 DOI: 10.1007/s12975-012-0168-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Accepted: 03/29/2012] [Indexed: 12/24/2022]
Abstract
Sodium MRI (sMRI) has undergone a tremendous amount of technical development during the last two decades that makes it a suitable tool for the study of human pathology in the acute setting within the constraints of a clinical environment. The salient role of the sodium ion during impaired ATP production during the course of brain ischemia makes sMRI an ideal tool for the study of ischemic tissue viability during stroke. In this paper, the current limitations of conventional MRI for the determination of tissue viability during evolving brain ischemia are discussed. This discussion is followed by a summary of the known findings about the dynamics of tissue sodium changes during brain ischemia. A mechanistic model for the explanation of these findings is presented together with the technical requirements for its investigation using clinical MRI scanners. An illustration of the salient features of the technique is also presented using a nonhuman primate model of reversible middle cerebral artery occlusion.
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Affiliation(s)
- Fernando E Boada
- MR Research Center, Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA,
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14
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An H, Ford AL, Vo K, Powers WJ, Lee JM, Lin W. Signal evolution and infarction risk for apparent diffusion coefficient lesions in acute ischemic stroke are both time- and perfusion-dependent. Stroke 2011; 42:1276-81. [PMID: 21454821 DOI: 10.1161/strokeaha.110.610501] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE This study aimed to examine the temporal relationship between tissue perfusion and apparent diffusion coefficient (ADC) changes within 6 hours of ischemic stroke onset and how different reperfusion patterns may affect tissue outcome in ADC lesions. METHODS Thirty-one participants were sequentially imaged at 3 hours, 6 hours, and 1 month post-stroke. Three regions of interest (ROIs) were defined within initial ADC lesions: ROI (1)reperf_3hour hyperacute reperfusion (within 3 hours), ROI (2)reperf_6hour acute reperfusion (3 to 6 hours), and ROI (3)nonreperf no reperfusion (by 6 hours). For each ROI, changes in ADC (ΔADC) from 3 to 6 hours and risks of infarction were examined. RESULTS The magnitude of initial ADC reduction was similar in all 3 ROIs (P=0.51). ΔADC was strongly associated with reperfusion (P<0.0001) but not with initial ADC reduction (P=0.83). ΔADC in ROI (1)reperf_3hour and ROI (2)reperf_6hour was significantly larger than that of ROI (3)nonreperf (P<0.05). Positive ΔADC was obtained from 3 to 6 hours in ROI (1)reperf_3hour that had restored perfusion before 3 hours, demonstrating a temporal delay between reperfusion and ADC changes. Risks of infarction were significantly higher in ROI (3)nonreperf than those in ROI (1)reperf_3hour and ROI (2)reperf_6hour. CONCLUSIONS Improvement in ADC did not occur coincidently with reperfusion but showed a temporal delay. Regions with similar initial ADC reductions at 3 hours had different evolution of ADC and infarction risks depending on when or if tissue reperfused. These findings provide a physiological basis for the observation that a single ADC measurement at a fixed time after stroke onset may not accurately predict tissue outcome.
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Affiliation(s)
- Hongyu An
- Department of Radiology and Biomedical Research Imaging Center, CB# 7513, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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15
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Water transport between CNS compartments: contributions of aquaporins and cotransporters. Neuroscience 2010; 168:941-56. [DOI: 10.1016/j.neuroscience.2009.09.016] [Citation(s) in RCA: 157] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2009] [Revised: 08/13/2009] [Accepted: 09/08/2009] [Indexed: 12/20/2022]
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Stiefel MF, Tomita Y, Marmarou A. Secondary ischemia impairing the restoration of ion homeostasis following traumatic brain injury. J Neurosurg 2005; 103:707-14. [PMID: 16266054 DOI: 10.3171/jns.2005.103.4.0707] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object. It is well established that posttraumatic secondary ischemia contributes to poor outcome. Ion dysfunction leading to cytotoxic edema is a primary force in the formation of ischemic brain edema and is a principal component of traumatic brain swelling. Because cell swelling is the result of net ion and water movement, it is crucial to have a thorough understanding of these transient phenomena. The purpose of this study was to characterize the effects of secondary ischemia following traumatic brain injury (TBI) on the ability to restore ion homeostasis.
Methods. Twenty-four Sprague—Dawley rats were divided into four groups of six animals each. The rats underwent transient forebrain ischemia via bilateral carotid artery occlusion combined with hypotension: 15 minutes of forebrain ischemia (Group 1); 60 minutes of forebrain ischemia (Group 2); impact acceleration/TBI (Group 3); and impact acceleration/TBI followed by 15 minutes of ischemia (Group 4).
Ischemia resulted in a rapid accumulation of [K+]e: 41.94 ± 13.65 and 66.33 ± 6.63 mM, respectively, in Groups 1 and 2, with a concomitant decrease of [Na+]e: 64 ± 18 mM and 72 ± 11 mM in Groups 1 and 2. Traumatic brain injury resulted in a less severe although identical trend in ion dysfunction ([K+]e 30.42 ± 11.67 mM and [Na+]e 63 ± 33 mM). Secondary ischemia resulted in prolonged and sustained ion dysfunction with a concomitant elevation of intracranial pressure (ICP).
Conclusions. Analysis of these results indicates that ischemia and TBI are sublethal in isolation; however, when TBI is associated with secondary ischemia, ion dysfunction is sustained and is associated with elevated ICP.
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Affiliation(s)
- Michael F Stiefel
- Department of Neurosurgery, Virginia Commonwealth University Health System, Richmond 23298-0508, USA
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18
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Boada FE, LaVerde G, Jungreis C, Nemoto E, Tanase C, Hancu I. Loss of cell ion homeostasis and cell viability in the brain: what sodium MRI can tell us. Curr Top Dev Biol 2005; 70:77-101. [PMID: 16338338 DOI: 10.1016/s0070-2153(05)70004-1] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
This chapter demonstrates the use of sodium magnetic resonance imaging (MRI) as a noninvasive, in vivo means to assess metabolic changes that ensue from loss of cell ion homeostasis due to cell death in the brain. The chapter is organized in two sections. In the first section, the constraints imposed on the imaging methods by the nuclear magnetic resonance (NMR) properties of the sodium ion are discussed and strategies for avoiding their potential limitations are addressed. The second section illustrates the use of sodium MRI for monitoring focal brain ischemia in permanent and temporary primate models of endovascular middle cerebral artery occlusion.
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Affiliation(s)
- Fernando E Boada
- Magnetic Resonance Research Center, Department of Radiology, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA
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19
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Keith CJ, Griffiths M, Petersen B, Anderson RJ, Miles KA. Computed tomography perfusion imaging in acute stroke. AUSTRALASIAN RADIOLOGY 2002; 46:221-30. [PMID: 12196228 DOI: 10.1046/j.1440-1673.2002.01026.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The development of thrombolytic and neuroprotective agents for the treatment of acute stroke has created an imperative for improved imaging techniques in the assessment of acute stroke. Five cases are presented to illustrate the value of perfusion CT in the evaluation of suspected acute stroke. To obtain the perfusion data, a rapid series of images was acquired without table movement following a bolus of contrast medium. Cerebral blood flow, cerebral blood volume and mean transit time were determined by mathematically modelling the temporal changes in contrast enhancement in the brain and vascular system. Pixel-by-pixel analysis allowed generation of perfusion maps. In two cases, CT-perfusion imaging usefully excluded acute stroke, including one patient in whom a low-density area on conventional CT was subsequently proven to be tumour. Cerebral ischaemia was confirmed in three cases, one with an old and a new infarction, one with a large conventional CT abnormality but only a small perfusion defect, and one demonstrating infarct and penumbra. Perfusion CT offers the ability to positively identify patients with non-haemorrhagic stroke in the presence of a normal conventional CT, to select those cases where thrombolysis is appropriate, and to provide an indication for prognosis.
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Affiliation(s)
- C J Keith
- Southern X-ray Clinics, School of Physical Sciences, Queensland University of Technology, Brisbane, Australia.
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20
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Stiefel MF, Marmarou A. Cation dysfunction associated with cerebral ischemia followed by reperfusion: a comparison of microdialysis and ion-selective electrode methods. J Neurosurg 2002; 97:97-103. [PMID: 12134939 DOI: 10.3171/jns.2002.97.1.0097] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Disruption of ionic homeostasis during ischemia is a well-characterized event and is identified by a rise in the concentration of extracellular potassium [K+]e, with a concomitant reduction in the concentration of extracellular sodium [Na+]e. Results of clinical studies in which microdialysis has been used, however, have shown only modest changes in the levels of extracellular ions. The object of this study was to measure [K+]e and [Na+]e by using ion-selective electrodes (ISEs) and to compare these measurements with those obtained using the well-established method of microdialysis. METHODS Fifteen Sprague-Dawley rats were separated into three groups. Five animals were subjected to a 15-minute period of ischemia, and another five animals to a 60-minute period of ischemia; animals in both of these groups received K+-free microdialysis perfusate. The third group of five rats underwent a 60-minute period of ischemia and received a reduced-Na+ microdialysis perfusate. Transient forebrain ischemia was produced by bilateral carotid artery occlusion combined with hypotension. A custom-fabricated glass Na+ electrode and a flexible plastic K+ and reference electrodes were used to monitor extracellular ion transients. Microdialysis samples were obtained with the aid of a 2-mm microdialysis probe that was perfused with K+-free mock cerebrospinal fluid at a rate of 2 microl/minute. Baseline measurements of [K+]e and [Na+]e, obtained using ISEs, were 3.41 +/- 0.09 mM and 145 +/- 7.75 mM. respectively. Ischemia resulted in a rapid accumulation of [K+]e (in animals subjected to 15 minutes of ischemia, the concentration was 41.9 +/- 13.7 mM; and in animals subjected to 60 minutes of ischemia, the concentration was 66.9 +/- 11.5 mM), with a concomitant decrease in [Na+]e (in animals subjected to 15 minutes of ischemia, the concentration was 71.7 +/- 2.9 mM; and in animals subjected to 60 minutes of ischemia, the concentration was 74.7 +/- 1.9 mM). A comparison of microdialysis and ISE methods revealed that microdialysis underestimated the [K+]e changes and was insensitive to concomitant [Na+]e alterations that occur during ischemia. CONCLUSIONS Our results indicate that the flexible ISE is a reliable and accurate tool for monitoring ionic dysfunction that accompanies brain injury.
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Affiliation(s)
- Michael F Stiefel
- Division of Neurosurgery, Medical College of Virginia, Virginia Commonwealth University, Richmond, USA
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21
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Chang HY, Hua LL, Morgan A, Lee SC. Inhibition of astrocyte TNFalpha expression by extracellular potassium. Brain Res 2001; 888:176-179. [PMID: 11146066 DOI: 10.1016/s0006-8993(00)03098-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
TNFalpha and IL-6 are cytokines of great interest, given the numerous biological activities and the documented expression in several central nervous system (CNS) pathologies. In this report, we have examined cultures of IL-1- or IL-1/IFNgamma-activated human fetal astrocytes as a model to study mechanisms of cytokine regulation in the inflamed CNS. Since one of the major functions of astrocytes is spatial buffering of K(+) ions, we examined the effect of high extracellular KCl on astrocyte cytokine expression by ribonuclease protection assay and ELISA. Results demonstrate that astrocyte TNFalpha production was potently inhibited by K(+) with 44 and 89% inhibition at 25 and 55 mM K+, respectively. In contrast, astrocyte IL-6 inhibition required higher concentrations of K+ (>/=75 mM). These results demonstrate a novel role for astrocyte potassium channel activity in modulation of glial cytokine production.
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Affiliation(s)
- H Y Chang
- Department of Pathology (F-717), Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
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22
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Li F, Silva MD, Liu KF, Helmer KG, Omae T, Fenstermacher JD, Sotak CH, Fisher M. Secondary decline in apparent diffusion coefficient and neurological outcomes after a short period of focal brain ischemia in rats. Ann Neurol 2001. [DOI: 10.1002/1531-8249(200008)48:2<236::aid-ana14>3.0.co;2-7] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Morgan AC, Chang HY, Liu JS, Hua LL, Lee SC. High extracellular potassium modulates nitric oxide synthase expression in human astrocytes. J Neurochem 2000; 74:1903-12. [PMID: 10800933 DOI: 10.1046/j.1471-4159.2000.0741903.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Inducible nitric oxide synthase (iNOS) is a molecule of great interest, given the numerous biological activities of nitric oxide and the documented expression of iNOS in several CNS pathologies. There also appears to be species-dependent regulation of iNOS expression as well as CNS-specific regulation. In this study, we have examined cultures of cytokine-activated primary human astrocytes as a model system with which to study the mechanisms of iNOS regulation in human CNS. As one of the major functions of astrocytes is spatial buffering of K+ ion, we examined the effect of high extracellular KCI on astrocyte iNOS expression. The results demonstrate that KCI at 25-75 mM potently inhibits astrocyte nitrite production stimulated by interleukin-1 (IL-1)/interferon-gamma (IFNgamma). In addition, several potassium channel inhibitors such as CsCl, tetraethylammonium, and 4-aminopyridine as well as nigericin inhibited astrocyte iNOS expression induced by IL-1/IFNgamma. These results demonstrate a novel role for astrocyte potassium channel activity in modulation of astrocyte function. They further suggest neural-specific mechanisms for glial iNOS regulation.
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Affiliation(s)
- A C Morgan
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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24
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Abiru Y, Katoh-Semba R, Nishio C, Hatanaka H. High potassium enhances secretion of neurotrophic factors from cultured astrocytes. Brain Res 1998; 809:115-26. [PMID: 9795177 DOI: 10.1016/s0006-8993(98)00849-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Elevation of extracellular potassium concentration ([K+]o) in the central nervous system (CNS), which is observed such after physiological stimuli and during ischemia, is known to be regulated by astrocytes. We suspected that in response to increased [K+]o, astrocytes might secrete some neurotrophic factor(s) to promote the survival of active and/or ischemically damaged neurons. In the present study, we examined neurotrophic activity contained in HK-ACM, i.e., astrocyte-conditioned medium (ACM) obtained after culturing astrocytes in 40 mM potassium-containing medium (HK medium). Addition of HK-ACM to basal forebrain cultures from postnatal 2-week-old (P2w) rats increased both the choline acetyltransferase (ChAT) activity (4.40-fold) and the number of ChAT-positive neurons (2.01-fold) as compared with non-conditioned HK medium. On the other hand, the neurotrophic effects of LK-ACM, i.e., ACM collected after culturing astrocytes in 4 mM potassium-containing medium (LK medium), were much weaker (2.85- and 1.41-fold for ChAT activity and number of ChAT-positive neurons, respectively) than those of HK-ACM. The neurotrophic effects of ACMs increased in a manner dependent on potassium concentration and on astrocyte culture time. Addition of an antibody against nerve growth factor (NGF) neutralized the neurotrophic effects of HK- and LK-ACMs. Direct quantification of NGF protein in ACMs by the two-site ELISA method demonstrated that a high concentration of potassium enhanced NGF secretion from cultured astrocytes. These results suggested that astrocytes secrete NGF in response to [K+]o elevation in the CNS.
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Affiliation(s)
- Y Abiru
- Division of Protein Biosynthesis, Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
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25
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Sick TJ, Feng ZC, Rosenthal M. Spatial stability of extracellular potassium ion and blood flow distribution in rat cerebral cortex after permanent middle cerebral artery occlusion. J Cereb Blood Flow Metab 1998; 18:1114-20. [PMID: 9778188 DOI: 10.1097/00004647-199810000-00008] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Extracellular potassium ion activity ([K+]o) increases precipitously during brain ischemia when blood flow falls below threshold values less than approximately 15 mL/100 g/min. This flow threshold for increase of [K+]o occurs also in focal ischemia producing gradient from ischemic core to adjacent normally perfused brain. In this study we investigated the spatial and temporal stability of extracellular potassium ion and blood flow gradients after permanent middle cerebral artery occlusion (MCAO) in rats. [K+]o and regional CBF were measured, respectively, with K+-sensitive and polarographic hydrogen-sensitive microelectrodes at different cortical locations in the middle cerebral artery distribution region. Spatial assessment of [K+]o and regional CBF was conducted at 30, 90, and 180 minutes after MCAO. [K+]o in the more lateral cortex (core) increased from near 3 mmol/L before MCAO to greater than 50 mmol/L and was associated with flow values less than 25% of pre-ischemic levels. Measurements medial to the core (penumbra) indicated progressively decreasing levels of [K+]o and improvement of CBF. There was a tendency for [K+]o in penumbral zones to decrease toward normal levels with time, but there was little dissipation of [K+]o in core regions. In contrast, the spatial CBF profile remained remarkably constant for the entire recording period. Thus, unlike infarction which has been reported to expand with time after focal ischemia, the spatial [K+]o disturbance tends to contract primarily due to decreasing [K+]o with time in the penumbra. Thus, steady state levels of [K+]o after focal ischemia may not be a valuable predictor of cell viability.
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Affiliation(s)
- T J Sick
- Department of Neurology, University of Miami School of Medicine, Florida 33177, USA
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Reddy K, Mallard C, Guan J, Marks K, Bennet L, Gunning M, Gunn A, Gluckman P, Williams C. Maturational change in the cortical response to hypoperfusion injury in the fetal sheep. Pediatr Res 1998; 43:674-82. [PMID: 9585015 DOI: 10.1203/00006450-199805000-00017] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A characteristic of perinatal encephalopathies are the distinct patterns of neuronal and glial cell loss. Cerebral hypoperfusion is thought to be a major cause of these lesions. Gestational age is likely to influence outcome. This study compares the cortical electrophysiologic and histopathologic responses to hypoperfusion injury between preterm and near term fetuses. Chronically instrumented 0.65 (93-99-d, n = 9) and 0.9 (119-133-d, n = 6) gestation fetal sheep underwent 30 min of cerebral hypoperfusion injury. The parasagittal cortical EEG and impedance (measure of cytotoxic edema) responses plus histologic outcome (3 d) were compared. The acute rise in impedance was similar in amplitude, but the onset was delayed (5.0 +/- 0.7 versus 9.1 +/- 1.1 min, p < 0.05) in the preterm fetuses relative to those near term. In contrast the extent of the secondary rise was reduced (p < 0.01) and peaked earlier in the preterm fetuses (19.8 +/- 1.0 versus 40.5 +/- 3.5 h, p < 0.01). Both groups had a similar fall in EEG spectral edge frequency. The preterm fetuses had a milder loss of EEG intensity at 72 h (-7.7 +/- 1.5 versus -12.8 +/- 0.9 dB, p < 0.05). At both ages there was a predominantly parasagittal cortical distribution of damage with a similar pattern of neuronal loss in the thalamus and striatum. There was extensive selective neuronal loss within the upper layers of the cortex in those near term. In contrast the preterm fetuses developed subcortical infarcts (p < 0.05). The cortical response to injury altered during the last trimester. The results suggest the severity of the delayed phase of cortical neuronal injury and selective neuronal loss increased near term. In contrast, the preterm fetuses had a more rapidly evolving injury leading to necrosis of the subcortical white matter.
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Affiliation(s)
- K Reddy
- Research Centre for Developmental Medicine and Biology, Department of Paediatrics, University of Auckland, New Zealand
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27
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Yamamoto T, Marmarou A, Stiefel MF, Tsuji O, Bullock R. Evaluation of homeostatic changes in CSF circulation: in vivo analysis of the effect of neurotransmitter accumulation in the extracellular space following transient global ischemia. ACTA NEUROCHIRURGICA. SUPPLEMENT 1998; 70:71-4. [PMID: 9416282 DOI: 10.1007/978-3-7091-6837-0_22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Accumulation of potassium and excitatory amino acids (EAA) in the extracellular space (ECS) following ischemia has been well documented. Careful monitoring of these transients is crucial to gain a better understanding of CNS pathophysiology. This study was initiated to determine if CSF concentrations of EAAs reflect those measured in the ECS. Transient global ischemia, 20 minutes in duration, was produced by clamping the left subclavian and innominate arteries combined with hemorrhagic hypotension. The accumulation of glutamate and electrolytes were measured in CSF and the extracellular fluid (ECF) of cerebral cortex. Microdialysis (MD) was utilized to measure the extracellular concentrations while direct sampling of CSF was provided via cannulation of the cisterna magna. Hydrogen clearance and laser doppler methods were used to monitor regional cortical CBF. Our results show that extracellular concentrations of potassium ([K+]ECF) and glutamate significantly increased following the initiation of ischemia (p < 0.05). The extracellular concentration of these substances decreased with the restoration of CBF. In CSF, a similar trend was observed following re-circulation (p < 0.05). However, CSF glutamate levels did not return to pre-ischemic values.
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Affiliation(s)
- T Yamamoto
- Division of Neurosurgery, Medical College of Virginia, Richmond, USA
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28
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Paschen W. Disturbances of calcium homeostasis within the endoplasmic reticulum may contribute to the development of ischemic-cell damage. Med Hypotheses 1996; 47:283-8. [PMID: 8910877 DOI: 10.1016/s0306-9877(96)90068-7] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
It is widely accepted that disturbances of calcium homeostasis play a key role in the development of cell damage produced by transient cerebral ischemia. It is believed that the sharp increase in cytosolic calcium activity during ischemia activates a cascade of calcium-dependent metabolic processes which ultimately destroy the integrity of the cell. However, it has never been taken into account that ischemic cell damage may, at least in part, be caused by a disturbance of calcium homeostasis within the endoplasmic reticulum after transient cerebral ischemia. In fact, depletion of the endoplasmic reticulum from calcium induces metabolic changes resembling, in many respects, those produced by transient cerebral ischemia: it causes an inhibition of the activity of the eucaryotic initiation factor elF-2 alpha (by phosphorylation), a disaggregation of polyribosomes and thus an inhibition of global protein synthesis, and an increased expression of certain genes such as transcription factors (c-fos and c-jun) and the glucose-related protein grp78. Finally, a depletion of calcium in the endoplasmic reticulum induces tissue damage within the brain and triggers apoptosis in neuronal and non-neuronal cells. It is therefore concluded that cell damage induced by transient ischemia may, at least in part, be caused by a disturbance of calcium homeostasis within the endoplasmic reticulum.
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Affiliation(s)
- W Paschen
- Max-Planck-Institute for Neurological Research, Department of Experimental Neurology, Köln, Germany
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Schmitz B, Fischer M, Bockhorst K, Hoehn-Berlage M, Hossmann KA. Resuscitation from cardiac arrest in cats: influence of epinephrine dosage on brain recovery. Resuscitation 1995; 30:251-62. [PMID: 8867715 DOI: 10.1016/0300-9572(95)00891-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The quality of brain recovery after cardiac arrest depends crucially on the speed of cardiac resuscitation because the low cerebral perfusion pressure during the resuscitation procedure facilitates the development of no-reflow. To accelerate return of spontaneous circulation, high dose epinephrine has been recommended but the effect on the dynamics of early brain recovery is still unknown. We, therefore, studied the dynamics of brain resuscitation after cardiopulmonary resuscitation (CPR) with standard and high dose epinephrine using non-invasive NMR techniques. Fifteen min cardiac arrest was induced in normothermic cats by ventricular fibrillation. CPR was performed using an inflatable pneumatic vest for cyclic chest compression. With the beginning of CPR the standard dose group received 0.02 mg/kg epinephrine (n = 6) and the high dose group received 0.2 mg/kg (n = 8). Brain recovery was monitored by magnetic resonance imaging of the apparent diffusion coefficient (ADC) of water for 3 h. Although high dose epinephrine treatment led to a significantly higher blood pressure during early reperfusion, rapidly changing heterogeneities of early brain recovery were observed in both groups. High dose epinephrine thus does not improve the quality of post-cardiac arrest brain recovery during the first 3 h of reperfusion.
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Affiliation(s)
- B Schmitz
- Department of Experimental Neurology, Max-Planck-Institute for Neurological Research, Cologne, Germany
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30
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Jalc P, Marsala J, Jalcová H. Postischemic reperfusion causes a massive calcium overload in the myelinated spinal cord fibers. MOLECULAR AND CHEMICAL NEUROPATHOLOGY 1995; 25:143-53. [PMID: 8534317 DOI: 10.1007/bf02960909] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The visualization of Ca binding in the myelinated axons of lumbosacral segments of rabbit was done at the electron microscopic level using the spinal cord ischemia model. To assess the calcium accumulation, the binding agent pyroantimonate was used. Nonsignificant Ca2+ binding was found in the myelinated axons after 40 min of ischemia followed immediately by perfusion fixation. A high concentration of calcium pyroantimonate deposits, seen as electron dense particles, was detected in the myelin interlamellar clefts and axoplasm. The paranodal region was the most affected site.
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Affiliation(s)
- P Jalc
- Institute of Neurobiology, Slovak Academy of Sciences, Kosice, Slovak Republic
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31
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Hossmann KA, Fischer M, Bockhorst K, Hoehn-Berlage M. NMR imaging of the apparent diffusion coefficient (ADC) for the evaluation of metabolic suppression and recovery after prolonged cerebral ischemia. J Cereb Blood Flow Metab 1994; 14:723-31. [PMID: 8063868 DOI: 10.1038/jcbfm.1994.93] [Citation(s) in RCA: 116] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Adult normothermic cats were submitted to 1-h complete cerebrocirculatory arrest by intrathoracic occlusion of the internal mammary, the innominate, and the subclavian arteries in combination with pharmacologically induced hypotension. After ischemia, recirculation was initiated at different blood pressure levels to manipulate the postischemia resuscitation conditions. The resulting spectrum of postischemic recovery was studied by combining nuclear magnetic resonance imaging of the apparent diffusion coefficient (ADC) with pictorial assays of brain tissue pH, ATP, glucose, and lactate. Before ischemia, the mean ADC (average of seven coronal slices of five cats) was 713 +/- 40 x 10(-6) mm2/s. After 10-min ischemia, ADC declined to 68% of control and after 50 min slightly further to 63% of control. During recirculation after 1-h ischemia, recovery of ADC varied depending on the initial reperfusion pressure and other systemic variables. In two animals ADC only transiently increased followed by a secondary decline below the postischemic level. In three other animals ADC returned to near control within 1 h of recirculation. The comparison of ADC changes with previously reported changes in extracellular volume revealed a close relationship, supporting the notion that ADC is a function of the intra/extracellular water compartmentation. Recovery of ADC correlated closely with tissue pH and metabolic recovery, studied 3 h after the initiation of recirculation. Animals without recovery of ADC exhibited global depletion of ATP and glucose and severe lactacidosis, whereas animals with recovery of ADC showed replenishment of ATP and glucose to near control and a substantial reversal of lactacidosis.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- K A Hossmann
- Max-Planck-Institute for Neurological Research, Department of Experimental Neurology, Cologne, Germany
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32
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Leybaert L, De Ley G. Interstitial and tissue cations and electrical potential after experimental spinal cord injury. Exp Brain Res 1994; 100:369-75. [PMID: 7813675 DOI: 10.1007/bf02738397] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Interstitial and tissue cations and electrical potential were studied in an experimental model of spinal cord contusion injury in anaesthetised cats. Measurements of interstitial ion activity in the grey matter at the injury site (with ion-selective electrodes), showed a decrease of sodium and calcium, an increase of potassium, a small acidification and a negative shift in the electrical potential 5 min after injury. The interstitial ionic changes were completely reversible within 90 min following injury. Measurements of the ion content in a tissue sample from the injury site (flame photometry) showed an increase of sodium and calcium and a decrease of potassium 5 min after injury. The magnitude of the post-injury sodium change was much larger than the potassium change, both for interstitial and tissue measurements. Treatment of the animals with the calcium entry blocker flunarizine before the injury did not influence the magnitude of post-injury interstitial calcium decrease but significantly increased the rate of subsequent recovery. Pre-injury flunarizine treatment also significantly increased the recovery rate of the electrical potential. The experiments suggest the occurrence of a net ionic shift towards the intracellular space, which may contribute to oedema formation in the very early post-injury period. The post-injury decrease of interstitial calcium activity is probably not mediated by flunarizine-sensitive calcium entry mechanisms; such mechanisms may, however, be involved in the subsequent recovery period for interstitial calcium activity. Calcium ions may be involved in the recovery process of the negative electrical potential after injury.
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Affiliation(s)
- L Leybaert
- Laboratorium voor Normale en Pathologische Fysiologie, Universiteit Gent, Universitair Ziekenhuis, Belgium
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33
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Effects of the Conventional Anticonvulsants, Phenytoin, Carbamazepine, and Valproic Acid, on Sodium-Potassium-Adenosine Triphosphatase in Acute Ischemic Brain. Neurosurgery 1994. [DOI: 10.1097/00006123-199406000-00014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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34
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Murakami A, Furui T. Effects of the conventional anticonvulsants, phenytoin, carbamazepine, and valproic acid, on sodium-potassium-adenosine triphosphatase in acute ischemic brain. Neurosurgery 1994; 34:1047-51; discussion 1051. [PMID: 8084389 DOI: 10.1227/00006123-199406000-00014] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The effects of phenytoin, carbamazepine and valproic acid on alterations in sodium-potassium-adenosine triphosphatase activity during ischemia were studied in the rat brain. Pretreatment with phenytoin and carbamazepine prevented a reduction of this activity, which, without either treatment, was observed in the cerebral hemisphere exposed to 30-minute ischemia resulting from unilateral middle cerebral artery occlusion. Valproic acid, on the other hand, did not principally affect the ischemic impairment of this membrane-bound enzyme activity. These results lend support to the previously proposed use of phenytoin in cerebral ischemia, but also suggest the therapeutic availability of another common anticonvulsant, carbamazepine, for treatment of the insult.
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Affiliation(s)
- A Murakami
- Department of Neurosurgery, Aichi Medical University, Japan
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35
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Affiliation(s)
- M Erecińska
- Department of Pharmacology, University of Pennsylvania, Philadelphia
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36
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Héron A, Lekieffre D, Le Peillet E, Lasbennes F, Seylaz J, Plotkine M, Boulu RG. Effects of an A1 adenosine receptor agonist on the neurochemical, behavioral and histological consequences of ischemia. Brain Res 1994; 641:217-24. [PMID: 8012824 DOI: 10.1016/0006-8993(94)90149-x] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Untreated rats and rats given the A1 receptor adenosine agonist, R-phenylisopropyladenosine (R-PIA), were subjected to four vessel ischemia. The effect of R-PIA on hippocampal amino acid release, hippocampal neuronal damage, exploratory behavior, learning capacity and global neurological score were evaluated. R-PIA decreased by half the glutamate released during ischemia and improved the global neurological scores 3, 24, 48, 78 h and 7 days after ischemia. But R-PIA had no effect on taurine/GABA release (during ischemia), hippocampal neuronal damage (7 days post-ischemia), exploratory behavior (48 h post-ischemia) or learning capacity (7 days post-ischemia). Thus, a decrease in glutamate release by R-PIA is not systematically correlated with an improvement of histological damage or learning capacity. Reduced glutamate release is not therefore a sufficient criterion on which to evaluate the neuroprotective capacity of a drug.
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Affiliation(s)
- A Héron
- Laboratoire de Recherches Cérébrovasculaires, URA 641 CNRS, Faculté de Médecine Villemin, UFR Lariboisière-Saint-Louis, Université Paris, VII, France
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37
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Arieff AI. Dialysis disequilibrium syndrome: current concepts on pathogenesis and prevention. Kidney Int 1994; 45:629-35. [PMID: 8196263 DOI: 10.1038/ki.1994.84] [Citation(s) in RCA: 105] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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38
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Otsubo K, Katayama Y, Kashiwagi F, Muramatsu H, Terashi A. Comparison of the effects of glycerol, mannitol, and urea on ischemic hippocampal damage in gerbils. ACTA NEUROCHIRURGICA. SUPPLEMENTUM 1994; 60:321-4. [PMID: 7976579 DOI: 10.1007/978-3-7091-9334-1_86] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The effects of glycerol and mannitol, as well as urea, on delayed neuronal death (DND) in the gerbil hippocampus were investigated. 20% solution of glycerol, mannitol and urea were prepared, and 6.5 ml/kg of each agent, or saline, was administered to male Mongolian gerbils intraperitoneally 30 min before ischemia. The animals were subjected to transient forebrain ischemia for 5 min. Seven days after the ischemic insult, the brains were fixed and stained for histopathological analysis. The number of normal neurons (neuronal density, ND) in a 1 mm linear length of hippocampal CA1 region was counted. ND of sham-operated group (n = 6) was 275.3 +/- 16.7 (mean +/- SD). ND in the saline-treated group (n = 6) was 14.8 +/- 5.0. ND of groups treated with glycerol (n = 6), mannitol (n = 6) and urea (n = 4) was 68.2 +/- 56.7 (p < 0.01), 52.8 +/- 54.4 (p < 0.01) and 12.0 +/- 2.5 (NS), respectively. The present study demonstrates that glycerol and mannitol have some protective effects against DND in the gerbil hippocampus, whereas urea has no effect.
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Affiliation(s)
- K Otsubo
- Second Department of Internal Medicine, Nippon Medical School, Tokyo, Japan
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39
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Kurata M. 31P and 23Na nuclear magnetic resonance study on forebrain ischemia in rats with shift reagent Dy(TTHA). J Anesth 1993; 7:325-33. [PMID: 15278819 DOI: 10.1007/s0054030070325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/1992] [Accepted: 12/01/1992] [Indexed: 10/26/2022]
Abstract
31P and 23Na nuclear magnetic resonance (NMR) spectroscopy was employed to study the dynamic changes in intracellular high-energy phosphates and sodium during 15 min of forebrain ischemia and recirculation in in vivo rat brain. In the presence of the shift reagent Dysprosium triethylenetetramine-N,N,N",N",N"',N"'-hexaacetic and [Dy(TTHA)], the sodium peak separated into two peaks, unshifted and shifted. During 15 min of ischemia, the unshifted sodium peak decreased and the shifted sodium peak increased. With recirculation, the unshifted and the shifted sodium peaks returned to the preischemia level within 10 min, but the shifted one increased during 30-60 min. Intracellular high-energy phosphates and intracellular pH (pHi) decreased during 15 min of ischemia and returned to the preischemia levels within 20 min of recirculation. We conclude that the decrease in unshifted sodium peak during ischemia is due to the decrease in subarachnoid sodium and the cellular influx of interstitial sodium would be minimum. The increase in shifted sodium peak during ischemia is considered to be due to the dilatation of cerebral blood vessels and the increase in interstitial sodium which was transported from subarachnoid space.
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Affiliation(s)
- M Kurata
- Department of Anesthesiology, Mie University School of Medicine, Tsu, Japan
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40
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Nakamura K, Hatakeyama T, Furuta S, Sakaki S. The role of early Ca2+ influx in the pathogenesis of delayed neuronal death after brief forebrain ischemia in gerbils. Brain Res 1993; 613:181-92. [PMID: 8186966 DOI: 10.1016/0006-8993(93)90898-w] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
To examine the role of calcium influx in the early phase after brief forebrain ischemia and subsequent delayed neuronal cell death in the hippocampus, 45Ca autoradiography and electron microscopic cytochemistry, by a combined oxalate-pyroantimonate method, were carried out in gerbil brains after 5 min bilateral common carotid arterial occlusion. Further, neuronal damage during the ischemic and postischemic periods was determined by conventional or immunohistochemical staining for microtubule-associated protein 2 (MAP2) with and without calcium-entry blockers. 45Ca autoradiography showed a high peak of calcium in the hippocampus at 5 min of recirculation. Electron cytochemical microscopy also demonstrated accumulation of intracellular calcium pyroantimonate deposits in the neuronal cells in all regions. At 30 min of reperfusion, amounts of calcium in the hippocampus returned to the control levels, and intracellular dense calcium pyroantimonate deposits were reduced in these areas. Loss of the reaction for MAP2 was noted in the medial CA1 of the hippocampus immediately after 5 min ischemia and at 5 and 30 min after reperfusion. MK-801 (10 mg kg-1), an N-methyl-D-aspartate (NMDA) receptor antagonist, injected intraperitoneally 1 h before ischemia, suppressed the early increase of calcium in the forebrain and neuronal cell necrosis in the CA1. However, neither injection of MK-801 30 min after reperfusion nor preischemic treatment with 0.5 mg kg-1 Nimodipine or 1 mg kg-1 Nicardipine, voltage-sensitive calcium channel antagonists, prevented neuronal death. In immunohistochemical staining for MAP2, the ischemic lesion in the medial CA1 maintained after 5 min ischemia and the subsequent early reperfusion period in the untreated brains was protected by the preischemic injection of 10 mg kg-1 MK-801, but was not restored by the injection of 0.5 mg kg-1 Nimodipine or 1 mg kg-1 Nicardipine. In conclusion, it is suggested that an early excess of calcium influx could be caused mainly by excitatory amino acid overload through NMDA receptor-mediated calcium channels during the ischemic and early postischemic periods.
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Affiliation(s)
- K Nakamura
- Department of Neurosurgery, Ehime University School of Medicine, Japan
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41
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Popp R, Hoyer J, Gögelein H. Mechanosensitive nonselective cation channels in the antiluminal membrane of cerebral capillaries (blood-brain barrier). EXS 1993; 66:101-105. [PMID: 7505643 DOI: 10.1007/978-3-0348-7327-7_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Single stretch-activated (SA) cation channels have been investigated in the antiluminal membrane of freshly isolated brain capillaries. SA-channels did not distinguish between K+ and Na+ ions and were also permeable to Ca2+ and Ba2+ ions. With monovalent cations in the patch pipette the single-channel conductance was 37 pS and with the divalent cations Ba2+ and Ca2+ slope conductance was 16 and 19 pS, respectively. The open probability of the SA-channel increased with increasing negative pressure as well as with depolarization. Cell swelling induced by hypotonic shock activated the SA-channels in cell-attached experiments. The contribution of SA-channels to the regulation of cerebrospinal fluid in brain edema is discussed.
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Affiliation(s)
- R Popp
- Max-Planck-Institut für Biophysik, Frankfurt, FRG
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42
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Hossmann KA. Disturbances of cerebral protein synthesis and ischemic cell death. PROGRESS IN BRAIN RESEARCH 1993; 96:161-77. [PMID: 8332739 DOI: 10.1016/s0079-6123(08)63265-3] [Citation(s) in RCA: 161] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- K A Hossmann
- Max-Planck-Institute for Neurological Research, Department of Experimental Neurology, Cologne, Germany
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43
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McIntosh TK. Novel pharmacologic therapies in the treatment of experimental traumatic brain injury: a review. J Neurotrauma 1993; 10:215-61. [PMID: 8258838 DOI: 10.1089/neu.1993.10.215] [Citation(s) in RCA: 214] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Delayed or secondary neuronal damage following traumatic injury to the central nervous system (CNS) may result from pathologic changes in the brain's endogenous neurochemical systems. Although the precise mechanisms mediating secondary damage are poorly understood, posttraumatic neurochemical changes may include overactivation of neurotransmitter release or re-uptake, changes in presynaptic or postsynaptic receptor binding, or the pathologic release or synthesis of endogenous "autodestructive" factors. The identification and characterization of these factors and the timing of the neurochemical cascade after CNS injury provides a window of opportunity for treatment with pharmacologic agents that modify synthesis, release, receptor binding, or physiologic activity with subsequent attenuation of neuronal damage and improvement in outcome. Over the past decade, a number of studies have suggested that modification of postinjury events through pharmacologic intervention can promote functional recovery in both a variety of animal models and clinical CNS injury. This article summarizes recent work suggesting that pharmacologic manipulation of endogenous systems by such diverse pharmacologic agents as anticholinergics, excitatory amino acid antagonists, endogenous opioid antagonists, catecholamines, serotonin antagonists, modulators of arachidonic acid, antioxidants and free radical scavengers, steroid and lipid peroxidation inhibitors, platelet activating factor antagonists, anion exchange inhibitors, magnesium, gangliosides, and calcium channel antagonists may improve functional outcome after brain injury.
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Affiliation(s)
- T K McIntosh
- Department of Surgery, University of Pennsylvania, Philadelphia
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44
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Lundbaek JA, Hansen AJ. Brain interstitial volume fraction and tortuosity in anoxia. Evaluation of the ion-selective micro-electrode method. ACTA PHYSIOLOGICA SCANDINAVICA 1992; 146:473-84. [PMID: 1492565 DOI: 10.1111/j.1748-1716.1992.tb09449.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The micro-electrode method for determination of interstitial volume fraction (alpha) (Nicholson & Phillips 1981), was evaluated. The extracellular marker, tetramethylammonium+, is iontophoretically ejected from a micropipette and the change in concentration measured at a distance by an ion-sensitive micro-electrode and fitted to a diffusion equation. We used suspensions of human red blood cells as a model system and found that the values of alpha determined by this method and by haematocrit measurement were linearly correlated (r = 0.94) and not significantly different. The micro-electrode method was used to characterize the interstitial space in rat brain cortex during normal conditions and during arrest of blood flow supply. Transport of solutes in interstitial space is governed by two characteristics, the interstitial volume fraction and the tortuosity factor. During control conditions, the interstitial volume fraction was 0.18 +/- 0.02 (mean +/- SEM), whereas it decreased to 0.07 +/- 0.01 in ischaemia. The tortuosity factor was 1.40 +/- 0.05 in controls and increased to 1.63 +/- 0.09 during ischaemia. Our measurements support the validity of the micro-electrode method (Nicholson & Phillips 1981) and demonstrate that arrest of blood supply changes interstitial diffusional characteristics of brain cortex mainly by diminishing the size of the interstitial diffusional space.
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Affiliation(s)
- J A Lundbaek
- Department of General Physiology and Biophysics, Panum Institute, University of Copenhagen, Denmark
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45
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Yang GY, Chen SF, Kinouchi H, Chan PH, Weinstein PR. Edema, cation content, and ATPase activity after middle cerebral artery occlusion in rats. Stroke 1992; 23:1331-6. [PMID: 1325690 DOI: 10.1161/01.str.23.9.1331] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND AND PURPOSE Reduction of cerebral blood flow results in several acute metabolic disturbances, including a reduction in Na,K-ATPase activity. The relation between this reduction and the onset of edema is unknown, as is the effect of restoration of blood flow. Therefore, we investigated the role of decreased Na,K-ATPase activity in the pathogenesis and time course of ischemic brain edema and reperfusion. METHODS The middle cerebral arteries of rats were occluded by cannulation with a nylon suture for 30, 60, 120, or 240 minutes. The animals were then decapitated (permanent occlusion) or the suture was withdrawn to allow 24 hours of reperfusion before decapitation (temporary occlusion). Na,K-ATPase activity and Na+, K+ and water contents were measured at various intervals. RESULTS In the ischemic hemisphere, Na,K-ATPase activity was significantly decreased at 30, 60, 120, and 240 minutes of permanent occlusion (p less than 0.05). There was also a significant decrease in rats subjected to 60 or 120 minutes of temporary occlusion followed by 24 hours of reperfusion. Water content increased after 60, 120, or 240 minutes of permanent occlusion (p less than 0.01); after 24 hours of reperfusion, water content remained elevated (p less than 0.01). The Na+ content increased after both permanent and temporary occlusion, and the K+ content decreased only after permanent occlusion. Increases in water content correlated with decreases in Na,K-ATPase activity after temporary occlusion and with the Na+:K+ ratio after permanent occlusion. CONCLUSION Reduction in Na,K-ATPase activity resulting in disruption of cellular ionic homeostasis may account for early development of cytotoxic brain edema after permanent occlusion of the middle cerebral artery. Such edema is also present 24 hours after 60 and 120 but not 30 minutes of temporary occlusion.
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Affiliation(s)
- G Y Yang
- Department of Neurological Surgery, School of Medicine, University of California, San Francisco
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46
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Minematsu K, Li L, Sotak CH, Davis MA, Fisher M. Reversible focal ischemic injury demonstrated by diffusion-weighted magnetic resonance imaging in rats. Stroke 1992; 23:1304-10; discussion 1310-1. [PMID: 1519287 DOI: 10.1161/01.str.23.9.1304] [Citation(s) in RCA: 227] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND AND PURPOSE Diffusion-weighted magnetic resonance imaging (DWI) can quantitatively display focal brain abnormalities within minutes after the onset of ischemia. We performed the present study to determine the effects of 1 and 2 hours of temporary ischemia on DWI. METHODS We examined DWI and T2-weighted magnetic resonance images (T2WI) during and after 1 and 2 hours of temporary middle cerebral artery occlusion in rats (n = 10 for each group). In a subgroup of four animals from each group, we employed perfusion magnetic resonance imaging to monitor cerebral perfusion. Neurological outcome and infarct size after survival for 24 hours were compared between the groups and correlated with DWI and T2WI studies. RESULTS Perfusion studies qualitatively documented hypoperfusion and reperfusion during and after temporary occlusion. Lesion size on DWI during reperfusion was significantly less than that during ischemia for 1 (55% decline, p less than 0.02) but not 2 hours of occlusion. The DWI signal intensity ratio (intensity compared with that in the contralateral homologous area) just before withdrawal of the occluder was significantly less in regions where the hyperintensity disappeared after withdrawal than in regions with persistent hyperintensity (p less than 0.002). The T2WI studies revealed few or no abnormalities, except after 2 hours of occlusion. The neurological outcome was significantly better in the 1-hour than in the 2-hour group (p less than 0.05). Postmortem infarct volume was significantly smaller in the 1-hour group than in the 2-hour group (p less than 0.05). The postwithdrawal DWI accurately predicted infarct size (R = 0.96, p less than 0.0001). CONCLUSIONS The present study indicates that DWI can rapidly display not only irreversible but also reversible ischemic brain damage and enhances the importance of DWI as a diagnostic modality for stroke.
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Affiliation(s)
- K Minematsu
- Department of Neurology, University of Massachusetts Medical School, Worcester
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47
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Abstract
This article examines the pathophysiology of lesions caused by focal cerebral ischemia. Ischemia due to middle cerebral artery occlusion encompasses a densely ischemic focus and a less densely ischemic penumbral zone. Cells in the focus are usually doomed unless reperfusion is quickly instituted. In contrast, although the penumbra contains cells "at risk," these may remain viable for at least 4 to 8 hours. Cells in the penumbra may be salvaged by reperfusion or by drugs that prevent an extension of the infarction into the penumbral zone. Factors responsible for such an extension probably include acidosis, edema, K+/Ca++ transients, and inhibition of protein synthesis. Central to any discussion of the pathophysiology of ischemic lesions is energy depletion. This is because failure to maintain cellular adenosine triphosphate (ATP) levels leads to degradation of macromolecules of key importance to membrane and cytoskeletal integrity, to loss of ion homeostasis, involving cellular accumulation of Ca++, Na+, and Cl-, with osmotically obligated water, and to production of metabolic acids with a resulting decrease in intra- and extracellular pH. In all probability, loss of cellular calcium homeostasis plays an important role in the pathogenesis of ischemic cell damage. The resulting rise in the free cytosolic intracellular calcium concentration (Ca++) depends on both the loss of calcium pump function (due to ATP depletion), and the rise in membrane permeability to calcium. In ischemia, calcium influx occurs via multiple pathways. Some of the most important routes depend on activation of receptors by glutamate and associated excitatory amino acids released from depolarized presynaptic endings. However, ischemia also interfers with the intracellular sequestration and binding of calcium, thereby contributing to the rise in intracellular Ca++. A second key event in the ischemic tissue is activation of anaerobic glucolysis. The main reason for this activation is inhibition of mitochondrial metabolism by lack of oxygen; however, other factors probably contribute. For example, there is a complex interplay between loss of cellular calcium homeostasis and acidosis. On the one hand, a rise in intracellular Ca++ is apt to cause mitochondrial accumulation of calcium. This must interfere with ATP production and enhance anaerobic glucolysis. On the other hand, acidosis must interfere with calcium binding, thereby contributing to the rise in intracellular Ca++.
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Affiliation(s)
- B K Siesjö
- Laboratory for Experimental Brain Research, Lund University Hospital, Sweden
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48
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Popp R, Hoyer J, Meyer J, Galla HJ, Gögelein H. Stretch-activated non-selective cation channels in the antiluminal membrane of porcine cerebral capillaries. J Physiol 1992; 454:435-49. [PMID: 1282158 PMCID: PMC1175613 DOI: 10.1113/jphysiol.1992.sp019272] [Citation(s) in RCA: 62] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
1. Single stretch-activated (SA) channels have been studied in isolated brain capillary endothelial cells as well as in the antiluminal membrane of intact porcine cerebral capillaries using the patch-clamp recording technique. 2. The SA channels were found to be cation selective and permeable to Na+, K+, Ba2+ and Ca2+. 3. With monovalent cations in the patch pipette, the channels showed inward rectification in cell-attached patches with a single-channel conductance of 37 pS at negative and 24 pS at positive clamp potentials. 4. With either 70 mM-Ca2+ or Ba2+ in the patch pipette, the current-voltage relation was linear with slope conductances of 16 and 19 pS, respectively. 5. Mean channel open probability increased with increasing pressure and with depolarizing clamp potentials. 6. Cell swelling induced by hypotonic shock activated the SA channels in cell-attached experiments. 7. The SA channel may be involved in cell volume or blood flow regulation. The contribution of these channels to the regulation of cerebrospinal salt and water content, especially in brain oedema, is discussed.
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Affiliation(s)
- R Popp
- Max-Planck-Institut für Biophysik, Frankfurt/Main, FRG
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49
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Sciotti VM, Roche FM, Grabb MC, Van Wylen DG. Adenosine receptor blockade augments interstitial fluid levels of excitatory amino acids during cerebral ischemia. J Cereb Blood Flow Metab 1992; 12:646-55. [PMID: 1352304 DOI: 10.1038/jcbfm.1992.89] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The excitotoxic hypothesis suggests that cerebral ischemic damage results in part from the accumulation of the excitatory and potentially toxic neurotransmitters glutamate and aspartate. Adenosine, which also increases during cerebral ischemia, is proposed to inhibit neurotransmitter release. The purpose of this study was to determine if adenosine receptor blockade exacerbates the accumulation of glutamate and aspartate during cerebral ischemia. Microdialysis probes, implanted bilaterally in the caudate nucleus of halothane-anesthetized rats, were used to (1) assess changes in interstitial fluid (ISF) glutamate, aspartate, adenosine, and adenosine metabolites; (2) measure local cerebral blood flow (H2 clearance); and (3) deliver 8-(p-sulfophenyl)theophylline (SPT), an adenosine receptor antagonist, locally to the brain. The probe on one side of the brain was perfused with artificial cerebrospinal fluid (CSF) containing 10(-3) M SPT, while the probe on the opposite side received only artificial CSF. Animals were exposed to 20 min of ischemia (carotid occlusion+arterial blood pressure = 50 mm Hg) followed by 60 min of reperfusion. Dialysate glutamate and aspartate increased during and after cerebral ischemia, but were increased to a greater extent in the presence of adenosine receptor blockade. Likewise, the increase in dialysate adenosine and adenosine metabolites was enhanced on the side of locally administered SPT. These data suggest that endogenous adenosine attenuates the accumulation of glutamate and aspartate during cerebral ischemia.
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Affiliation(s)
- V M Sciotti
- Department of Physiology, School of Medicine and Biomedical Sciences, State University of New York, Buffalo 14215
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50
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Stadlin A, Tsang D, MacDonall JS, Mahadik SP, Karpiak SE. An in vitro study on increased neuronal and astrocytic vulnerability to neurotoxic injury after in utero cocaine exposure: the reversal effects of GM1 treatment. PROGRESS IN BRAIN RESEARCH 1992; 94:339-50. [PMID: 1363146 DOI: 10.1016/s0079-6123(08)61763-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- A Stadlin
- Department of Anatomy, Chinese University of Hong Kong, N.T
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