1
|
Yamasaki T, Mori W, Ohkubo T, Hiraishi A, Zhang Y, Kurihara Y, Nengaki N, Tashima H, Fujinaga M, Zhang MR. Potential for in vivo visualization of intracellular pH gradient in the brain using PET imaging. Brain Commun 2024; 6:fcae172. [PMID: 38863573 PMCID: PMC11166174 DOI: 10.1093/braincomms/fcae172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 04/16/2024] [Accepted: 05/22/2024] [Indexed: 06/13/2024] Open
Abstract
Intracellular pH is a valuable index for predicting neuronal damage and injury. However, no PET probe is currently available for monitoring intracellular pH in vivo. In this study, we developed a new approach for visualizing the hydrolysis rate of monoacylglycerol lipase, which is widely distributed in neurons and astrocytes throughout the brain. This approach uses PET with the new radioprobe [11C]QST-0837 (1,1,1,3,3,3-hexafluoropropan-2-yl-3-(1-phenyl-1H-pyrazol-3-yl)azetidine-1-[11C]carboxylate), a covalent inhibitor containing an azetidine carbamate skeleton for monoacylglycerol lipase. The uptake and residence of this new radioprobe depends on the intracellular pH gradient, and we evaluated this with in silico, in vitro and in vivo assessments. Molecular dynamics simulations predicted that because the azetidine carbamate moiety is close to that of water molecules, the compound containing azetidine carbamate would be more easily hydrolyzed following binding to monoacylglycerol lipase than would its analogue containing a piperidine carbamate skeleton. Interestingly, it was difficult for monoacylglycerol lipase to hydrolyze the azetidine carbamate compound under weakly acidic (pH 6) conditions because of a change in the interactions with water molecules on the carbamate moiety of their complex. Subsequently, an in vitro assessment using rat brain homogenate to confirm the molecular dynamics simulation-predicted behaviour of the azetidine carbamate compound showed that [11C]QST-0837 reacted with monoacylglycerol lipase to yield an [11C]complex, which was hydrolyzed to liberate 11CO2 as a final product. Additionally, the 11CO2 liberation rate was slower at lower pH. Finally, to indicate the feasibility of estimating how the hydrolysis rate depends on intracellular pH in vivo, we performed a PET study with [11C]QST-0837 using ischaemic rats. In our proposed in vivo compartment model, the clearance rate of radioactivity from the brain reflected the rate of [11C]QST-0837 hydrolysis (clearance through the production of 11CO2) in the brain, which was lower in a remarkably hypoxic area than in the contralateral region. In conclusion, we indicated the potential for visualization of the intracellular pH gradient in the brain using PET imaging, although some limitations remain. This approach should permit further elucidation of the pathological mechanisms involved under acidic conditions in multiple CNS disorders.
Collapse
Affiliation(s)
- Tomoteru Yamasaki
- Department of Advanced Nuclear Medicine Sciences, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
| | - Wakana Mori
- Department of Advanced Nuclear Medicine Sciences, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
| | - Takayuki Ohkubo
- Department of Advanced Nuclear Medicine Sciences, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
- SHI Accelerator Service Co. Ltd., Tokyo 141-0031, Japan
| | - Atsuto Hiraishi
- Department of Advanced Nuclear Medicine Sciences, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
| | - Yiding Zhang
- Department of Advanced Nuclear Medicine Sciences, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
| | - Yusuke Kurihara
- Department of Advanced Nuclear Medicine Sciences, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
- SHI Accelerator Service Co. Ltd., Tokyo 141-0031, Japan
| | - Nobuki Nengaki
- Department of Advanced Nuclear Medicine Sciences, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
- SHI Accelerator Service Co. Ltd., Tokyo 141-0031, Japan
| | - Hideaki Tashima
- Department of Advanced Nuclear Medicine Sciences, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
| | - Masayuki Fujinaga
- Department of Advanced Nuclear Medicine Sciences, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
| | - Ming-Rong Zhang
- Department of Advanced Nuclear Medicine Sciences, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
| |
Collapse
|
2
|
Protective Role of Chronic Exercise Training in Modulating the Impact of Hyperglycemia on Vascular Sensitivity to Ischemia-Reperfusion. Nutrients 2023; 15:nu15010212. [PMID: 36615872 PMCID: PMC9823667 DOI: 10.3390/nu15010212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 12/22/2022] [Accepted: 12/28/2022] [Indexed: 01/03/2023] Open
Abstract
Hyperglycemia (HG) is associated with increased mortality and morbidity in acute ischemic events. Regardless of the tissue or organs involved, the vascular endothelium is a key target of ischemia-reperfusion (I/R) injury severity. Among endothelium-protective strategies, exercise has been widely described as useful. However, whether this strategy is able to impact the deleterious effect of HG on endothelial function during I/R has never been challenged. For this, 48 male Wistar rats were randomized into 4 groups: sedentary (Sed) or exercised (Ex, 45 min/day, 5 days/week for 5 weeks) rats, treated (hyperglycemic, HG) or not (normoglycemic, NG) with streptozotocin (40 mg/kg, 48 h before procedure). Vascular I/R (120/15 min) was performed by clamping the femoral artery. Arterial and downstream muscular perfusions were assessed using laser speckle contrast imaging. Vascular endothelial function was assessed in vivo 15 min after reperfusion. HG was responsible for impairment of reperfusion blood flow as well as endothelial function. Interestingly exercise was able to prevent those impairments in the HG group. In agreement with the previous results, HG increased reactive oxygen species production and decreased nitric oxide bioavailability whereas exercise training normalized these parameters. It, therefore, appears that exercise may be an effective prevention strategy against the exacerbation of vascular and muscular damage by hyperglycemia during I/R.
Collapse
|
3
|
Yan Y, Tong F, Chen J. Endogenous BMP-4/ROS/COX-2 Mediated IPC and Resveratrol Alleviated Brain Damage. Curr Pharm Des 2020; 25:1030-1039. [PMID: 31113339 DOI: 10.2174/1381612825666190506120611] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 04/18/2019] [Indexed: 11/22/2022]
Abstract
The objective of the study was to examine the therapeutic role of combined ischemic preconditioning (IPC) and resveratrol (RES) on brain ischemia/reperfusion injury (BI/RI) by modulating endogenous bone morphogenetic protein-4 (BMP-4)/reactive oxygen species (ROS)/cyclooxygenase-2 (COX-2) in rats. Sprague Dawley (SD) rats were pretreated with 20 mg/kg RES (20 mg/kg RES was administered once a day via intraperitoneal injection 7 days prior to the I/R procedure) and IPC (equal volumes of saline were administered once a day by intraperitoneal injection over 7 days, and the bilateral common carotid arteries were separated for clamp 5 minutes followed by 5 minutes of reperfusion prior to the I/R procedure), and then subjected to 2 hours of ischemia and 22 hours of reperfusion. Blood and cerebral tissues were collected, cerebral pathological injuries and infarct sizes were investigated, serum interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) levels were measured, the activities of superoxide dismutase (SOD) and ROS were calculated, the contents of methane dicarboxylic aldehyde (MDA), IL-6, TNF-α and hemodynamic change were estimated, and expression levels of b-cell lymphoma-2 (Bcl-2), bcl-2-associated x (Bax), BMP-4 and COX-2 were assessed in cerebral tissues. IPC, RES and a combination of IPC and RES preconditioning ameliorated the pathological damage and infarct sizes, reduced cerebral oxidative stress damage, alleviated inflammatory damage, restrained apoptosis, and downregulated the expression levels of BMP-4 and COX-2 compared with those of the ischemia/reperfusion (I/R) group. This study suggested a combined strategy that could enhance protection against BI/RI in clinical brain disease.
Collapse
Affiliation(s)
- Ying Yan
- Department of Rehabilitation Medicine, Zhejiang Chinese Medical University, The Third Clinical Medicine, Hangzhou, Zhejiang, China
| | - Fei Tong
- Department of Pathology and Pathophysiology, Provincial Key Discipline of Pharmacology, Jiaxing University Medical College, Jiaxing, China
| | - Jianer Chen
- Department of Rehabilitation Medicine, Zhejiang Chinese Medical University, The Third Clinical Medicine, Hangzhou, Zhejiang, China.,Integrated Medicine Research Center for Neurological Rehabilitation College of Medicine, Jiaxing University, Jiaxing, 314001, China
| |
Collapse
|
4
|
Charriaut-Marlangue C, Baud O. A Model of Perinatal Ischemic Stroke in the Rat: 20 Years Already and What Lessons? Front Neurol 2018; 9:650. [PMID: 30131764 PMCID: PMC6090994 DOI: 10.3389/fneur.2018.00650] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 07/19/2018] [Indexed: 12/18/2022] Open
Abstract
Neonatal hypoxia-ischemia (HI) and ischemia are a common cause of neonatal brain injury resulting in cerebral palsy with subsequent learning disabilities and epilepsy. Recent data suggest a higher incidence of focal ischemia-reperfusion located in the middle cerebral artery (MCA) territory in near-term and newborn babies. Pre-clinical studies in the field of cerebral palsy research used, and still today, the classical HI model in the P7 rat originally described by Rice et al. (1). At the end of the 90s, we designed a new model of focal ischemia in the P7 rat to explore the short and long-term pathophysiology of neonatal arterial ischemic stroke, particularly the phenomenon of reperfusion injury and its sequelae (reported in 1998). Cerebral blood-flow and cell death/damage correlates have been fully characterized. Pharmacologic manipulations have been applied to the model to test therapeutic targets. The model has proven useful for the study of seizure occurrence, a clinical hallmark for neonatal ischemia in babies. Main pre-clinical findings obtained within these 20 last years are discussed associated to clinical pattern of neonatal brain damage.
Collapse
Affiliation(s)
| | - Olivier Baud
- INSERM U1141 PROTECT, Université Paris Diderot, Sorbonne Paris Cité, Hôpital Robert Debré, Paris, France.,Division of Neonatology and Pediatric Intensive Care, Children's Hospital, Geneva University Hospitals (HUG), University of Geneva, Geneva, Switzerland
| |
Collapse
|
5
|
The Protective Effect of the Total Flavonoids of Abelmoschus esculentus L. Flowers on Transient Cerebral Ischemia-Reperfusion Injury Is due to Activation of the Nrf2-ARE Pathway. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:8987173. [PMID: 30174782 PMCID: PMC6098902 DOI: 10.1155/2018/8987173] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Revised: 06/14/2018] [Accepted: 06/23/2018] [Indexed: 11/18/2022]
Abstract
Abelmoschus esculentus L. has favorable nutritional/medicinal features. We found the content of total flavonoids in flower extract to be the highest (788.56 mg/g) of all the different parts of A. esculentus; according to high-performance liquid chromatography, the quercetin-3-O-[β-D-glu-(1 → 6)]-β-D-glucopyranoside content was 122.13 mg/g. Protective effects of an extract of the total flavonoids of A. esculentus flowers (AFF) on transient cerebral ischemia-reperfusion injury (TCI-RI) were investigated. Compared with the model group, mice treated with AFF (300 mg/kg) for 7 days showed significantly reduced neurologic deficits, infarct area, and histologic changes in brain tissue, accompanied by increased contents of superoxide dismutase, whereas contents of nitric oxide and malondialdehyde decreased. AFF upregulated the expression of Nrf2, HO-1, and NQO1. These data suggest that AFF protects against TCI-RI by scavenging free radicals and activating the Nrf2-ARE pathway.
Collapse
|
6
|
Cui HX, Chen JH, Li JW, Cheng FR, Yuan K. Protection of Anthocyanin from Myrica rubra against Cerebral Ischemia-Reperfusion Injury via Modulation of the TLR4/NF-κB and NLRP3 Pathways. Molecules 2018; 23:E1788. [PMID: 30036952 PMCID: PMC6099489 DOI: 10.3390/molecules23071788] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 07/16/2018] [Accepted: 07/18/2018] [Indexed: 01/10/2023] Open
Abstract
Myrica rubra (MR) is rich in anthocyanins, and it has good anti-cancer, anti-aging, antioxidant, and antiviral effects. The proportion of disability and death caused by ischemic stroke gradually increased, becoming a major disease that is harmful to human health. However, research on effects of anthocyanin from MR on cerebral ischemia-reperfusion (I/R) injury is rare. In this study, we prepared eight purified anthocyanin extracts (PAEs) from different types of MR, and examined the amounts of total anthocyanin (TA) and cyanidin-3-O-glucoside (C-3-G). After one week of PAE treatment, the cerebral infarction volume, disease damage, and contents of nitric oxide and malondialdehyde were reduced, while the level of superoxide dismutase was increased in I/R mice. Altogether, our results show that Boqi¹ MR contained the most TA (22.07%) and C-3-G (21.28%), and that PAE isolated from Dongkui MR can protect the brain from I/R injury in mice, with the mechanism possibly related to the Toll-like receptor 4 (TLR4)/ nuclear factor-κB (NF-κB) and NOD-like receptor pyrin domain-containing 3 protein (NLRP3) pathways.
Collapse
Affiliation(s)
- Hong-Xin Cui
- College of Pharmacy, Henan University of Chinese Medicine, Zhengzhou 450046, China.
- Collaborative Innovation Center for Respiratory Disease Diagnosis and Treatment & Chinese Medicine Development of Henan Province, Zhengzhou 450046, China.
| | - Ji-Hong Chen
- College of Pharmacy, Henan University of Chinese Medicine, Zhengzhou 450046, China.
| | - Jing-Wan Li
- Forestry and biotechnology College, Zhejiang Agriculture and Forestry University, Lin'an 311300, China.
| | - Fang-Rong Cheng
- College of Pharmacy, Henan University of Chinese Medicine, Zhengzhou 450046, China.
| | - Ke Yuan
- Jiyang College of Zhejiang Agriculture and Forestry University, Zhu'ji 311800, China.
| |
Collapse
|
7
|
Fukuta T, Ishii T, Asai T, Sato A, Kikuchi T, Shimizu K, Minamino T, Oku N. Treatment of stroke with liposomal neuroprotective agents under cerebral ischemia conditions. Eur J Pharm Biopharm 2015; 97:1-7. [PMID: 26455340 DOI: 10.1016/j.ejpb.2015.09.020] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 08/21/2015] [Accepted: 09/30/2015] [Indexed: 01/09/2023]
Abstract
Since the proportion of patients given thrombolytic therapy with tissue plasminogen activator (t-PA) is very limited because of the narrow therapeutic window, the development of new therapies for ischemic stroke has been desired. We previously reported that liposomes injected intravenously accumulate in the ischemic region of the brain via disruption of the blood-brain barrier that occurs under cerebral ischemia. In the present study, we investigated the efficacy of a liposomal neuroprotective agent in middle cerebral artery occlusion (MCAO) rats to develop ischemic stroke therapy prior to the recovery of cerebral blood flow. For this purpose, PEGylated liposomes encapsulating FK506 (FK506-liposomes) were prepared and injected intravenously into MCAO rats after a 1-h occlusion. This treatment significantly suppressed the expansion of oxidative stress and brain cell damage. In addition, administration of FK506-liposomes before reperfusion significantly ameliorated motor function deficits of the rats caused by ischemia/reperfusion injury. These findings suggest that FK506-liposomes effectively exerted a neuroprotective effect during ischemic conditions, and that combination therapy with a liposomal neuroprotectant plus t-PA could be a promising therapeutic strategy for ischemic stroke.
Collapse
Affiliation(s)
- Tatsuya Fukuta
- Department of Medical Biochemistry, University of Shizuoka Graduate School of Pharmaceutical Sciences, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan; Japan Society for the Promotion of Science (JSPS), 8 Ichiban-cho, Chiyoda-ku, Tokyo 102-8472, Japan
| | - Takayuki Ishii
- Department of Medical Biochemistry, University of Shizuoka Graduate School of Pharmaceutical Sciences, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Tomohiro Asai
- Department of Medical Biochemistry, University of Shizuoka Graduate School of Pharmaceutical Sciences, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Akihiko Sato
- Department of Medical Biochemistry, University of Shizuoka Graduate School of Pharmaceutical Sciences, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Takashi Kikuchi
- Department of Medical Biochemistry, University of Shizuoka Graduate School of Pharmaceutical Sciences, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Kosuke Shimizu
- Department of Medical Biochemistry, University of Shizuoka Graduate School of Pharmaceutical Sciences, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Tetsuo Minamino
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Naoto Oku
- Department of Medical Biochemistry, University of Shizuoka Graduate School of Pharmaceutical Sciences, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
| |
Collapse
|
8
|
Abe K, Tonomura M, Ito M, Takai N, Imamoto N, Rokugawa T, Momosaki S, Fukumoto K, Morimoto K, Inoue O. Imaging of reactive oxygen species in focal ischemic mouse brain using a radical trapping tracer [(3)H]hydromethidine. EJNMMI Res 2015; 5:115. [PMID: 26160496 PMCID: PMC4498001 DOI: 10.1186/s13550-015-0115-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 06/12/2015] [Indexed: 12/24/2022] Open
Abstract
Background Reactive oxygen species (ROS) have been implicated in the pathophysiology of the brain after ischemic stroke. In this study, we investigate the generation of brain ROS after transient focal ischemia in mice using a radical trapping radiotracer, [3H]-labeled N-methyl-2,3-diamino-6-phenyl-dihydrophenanthridine ([3H]hydromethidine), which we recently reported as a ROS imaging probe. We also examined the effect of dimethylthiourea (DMTU), a hydroxyl radical scavenger, on brain ROS generation and infarct volume after transient focal ischemia in mice. Methods [3H]Hydromethidine was intravenously injected into mice at 1, 2, 5, and 7 h after transient middle cerebral artery occlusion (tMCAO), and then, the brain autoradiogram was acquired at 60 min after tracer injection. Brain infarct volumes at 24 h after tMCAO were assessed by 2,3,5-triphenyltetrazolium chloride staining. Results Accumulation of radioactivity was observed in the ipsilateral striatum and cortex at 1 h after tMCAO. The increase of radioactivity was attenuated at 2 h after tMCAO and then became maximized at 5 h. The high accumulation of radioactivity remained until 7 h after tMCAO. DMTU treatment significantly attenuated the accumulation of radioactivity in the ipsilateral hemisphere at 1, 5, and 7 h after tMCAO. Brain infarct volumes were also significantly reduced in DMTU-treated mice at 24 h after tMCAO. Conclusions These results indicated that [3H]hydromethidine is a useful radiotracer for detecting in vivo brain ROS generation such as hydroxyl radical after ischemic injury.
Collapse
Affiliation(s)
- Kohji Abe
- Department of Drug Metabolism & Pharmacokinetics, Research Laboratory for Development, Shionogi & Co., Ltd., 3-1-1 Futaba-cho, Toyonaka, Osaka, 561-0825, Japan,
| | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Onetti Y, Dantas AP, Pérez B, Cugota R, Chamorro A, Planas AM, Vila E, Jiménez-Altayó F. Middle cerebral artery remodeling following transient brain ischemia is linked to early postischemic hyperemia: a target of uric acid treatment. Am J Physiol Heart Circ Physiol 2015; 308:H862-74. [PMID: 25637543 DOI: 10.1152/ajpheart.00001.2015] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Accepted: 01/28/2015] [Indexed: 12/26/2022]
Abstract
Ischemia impairs blood supply to the brain, and reperfusion is important to restore cerebral blood flow (CBF) and rescue neurons from cell death. However, reperfusion can induce CBF values exceeding the basal values before ischemia. This hyperemic effect has been associated with a worse ischemic brain damage, albeit the mechanisms that contribute to infarct expansion are not clear. In this study, we investigated the influence of early postischemic hyperemia on brain damage and middle cerebral artery (MCA) properties and the effect of treatment with the endogenous antioxidant uric acid (UA). The MCA was occluded for 90 min followed by 24 h reperfusion in adult male Sprague-Dawley rats. Cortical CBF increases at reperfusion beyond 20% of basal values were taken as indicative of hyperemia. UA (16 mg/kg) or vehicle (Locke's buffer) was administered intravenously 135 min after MCA occlusion. Hyperemic compared with nonhyperemic rats showed MCA wall thickening (sham: 22.4 ± 0.8 μm; nonhyperemic: 23.1 ± 1.2 μm; hyperemic: 27.8 ± 0.9 at 60 mmHg; P < 0.001, hyperemic vs. sham) involving adventitial cell proliferation, increased oxidative stress, and interleukin-18, and more severe brain damage. Thus MCA remodeling after ischemia-reperfusion takes place under vascular oxidative and inflammatory stress conditions linked to hyperemia. UA administration attenuated MCA wall thickening, induced passive lumen expansion, and reduced brain damage in hyperemic rats, although it did not increase brain UA concentration. We conclude that hyperemia at reperfusion following brain ischemia induces vascular damage that can be attenuated by administration of the endogenous antioxidant UA.
Collapse
Affiliation(s)
- Yara Onetti
- Facultat de Medicina, Departament de Farmacologia, Terapèutica i Toxicologia, Institut de Neurociències, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Ana P Dantas
- Institut Clínic del Tòrax, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain
| | - Belén Pérez
- Facultat de Medicina, Departament de Farmacologia, Terapèutica i Toxicologia, Institut de Neurociències, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Roger Cugota
- Facultat de Medicina, Departament de Farmacologia, Terapèutica i Toxicologia, Institut de Neurociències, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Angel Chamorro
- Functional Unit of Cerebrovascular Diseases, Hospital Clínic de Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain; and
| | - Anna M Planas
- Departament d'Isquèmia Cerebral i Neurodegeneració, Institut de Recerca Biomèdica, Consejo Superior de Investigaciones Científicas, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain
| | - Elisabet Vila
- Facultat de Medicina, Departament de Farmacologia, Terapèutica i Toxicologia, Institut de Neurociències, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Francesc Jiménez-Altayó
- Facultat de Medicina, Departament de Farmacologia, Terapèutica i Toxicologia, Institut de Neurociències, Universitat Autònoma de Barcelona, Bellaterra, Spain;
| |
Collapse
|
10
|
Leger PL, Bonnin P, Lacombe P, Couture-Lepetit E, Fau S, Renolleau S, Gharib A, Baud O, Charriaut-Marlangue C. Dynamic spatio-temporal imaging of early reflow in a neonatal rat stroke model. J Cereb Blood Flow Metab 2013; 33:137-45. [PMID: 23047273 PMCID: PMC3597373 DOI: 10.1038/jcbfm.2012.147] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The aim of the study was to better understand blood-flow changes in large arteries and microvessels during the first 15 minutes of reflow in a P7 rat model of arterial occlusion. Blood-flow changes were monitored by using ultrasound imaging with sequential Doppler recordings in internal carotid arteries (ICAs) and basilar trunk. Relative cerebral blood flow (rCBF) changes were obtained by using laser speckle Doppler monitoring. Tissue perfusion was measured with [(14)C]-iodoantipyrine autoradiography. Cerebral energy metabolism was evaluated by mitochondrial oxygen consumption. Gradual increase in mean blood-flow velocities illustrated a gradual perfusion during early reflow in both ICAs. On ischemia, the middle cerebral artery (MCA) territory presented a residual perfusion, whereas the caudal territory remained normally perfused. On reflow, speckle images showed a caudorostral propagation of reperfusion through anastomotic connections, and a reduced perfusion in the MCA territory. Autoradiography highlighted the caudorostral gradient, and persistent perfusion in ventral and medial regions. These blood-flow changes were accompanied by mitochondrial respiration impairment in the ipsilateral cortex. Collectively, these data indicate the presence of a primary collateral pathway through the circle of Willis, providing an immediate diversion of blood flow toward ischemic regions, and secondary efficient cortical anastomoses in the immature rat brain.
Collapse
|
11
|
Dalkara T, Arsava EM. Can restoring incomplete microcirculatory reperfusion improve stroke outcome after thrombolysis? J Cereb Blood Flow Metab 2012; 32:2091-9. [PMID: 23047270 PMCID: PMC3519416 DOI: 10.1038/jcbfm.2012.139] [Citation(s) in RCA: 162] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 08/31/2012] [Accepted: 09/03/2012] [Indexed: 12/27/2022]
Abstract
Substantial experimental data and recent clinical evidence suggesting that tissue reperfusion is a better predictor of outcome after thrombolysis than recanalization necessitate that patency of microcirculation after recanalization should be reevaluated. If indeed microcirculatory blood flow cannot be sufficiently reinstituted despite complete recanalization as commonly observed in coronary circulation, it may be one of the factors contributing to low efficacy of thrombolysis in stroke. Although microvascular no-reflow is considered an irreversible process that prevents tissue recovery from injury, emerging evidence suggests that it might be reversed with pharmacological agents administered early during recanalization. Therefore, therapeutic approaches aiming at reducing microvascular obstructions may improve success rate of recanalization therapies. Importantly, promoting oxygen delivery to the tissue, where entrapped erythrocytes cannot circulate in capillaries, with ongoing serum flow may improve survival of the underreperfused tissue. Altogether, these developments bring about the exciting possibility that benefit of reperfusion therapies can be further improved by restoring microcirculatory function because survival in the penumbra critically depends on adequate blood supply. Here, we review the available evidence suggesting presence of an 'incomplete microcirculatory reperfusion' (IMR) after focal cerebral ischemia and discuss potential means that may help investigate IMR in stroke patients after recanalization therapies despite technical limitations.
Collapse
Affiliation(s)
- Turgay Dalkara
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey.
| | | |
Collapse
|
12
|
Ceulemans AG, Hernot S, Zgavc T, Caveliers V, Hachimi-Idrissi S, Sarre S, Lahoutte T, Michotte Y. Serial semiquantitative imaging of brain damage using micro-SPECT and micro-CT after endothelin-1-induced transient focal cerebral ischemia in rats. J Nucl Med 2011; 52:1987-92. [PMID: 22049462 DOI: 10.2967/jnumed.110.085902] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED In this study, we validated the use of (99m)Tc-hexamethylpropyleneamine oxime ((99m)Tc-HMPAO) micro-SPECT combined with micro-CT for semiquantification of the infarct size after an experimental stroke in rats and compared our observations with those obtained from histology. This imaging strategy was applied to measure the longitudinal effect of mild hypothermia on the progression of brain damage after stroke in rats. METHODS The endothelin-1 model was used to elicit a transient focal cerebral ischemia in rats. This resulted in a reproducible insult in which the core is represented by the striatum and the penumbra by the cortex. Micro-SPECT and micro-CT images were taken at 1, 3, and 7 d after infusion of endothelin-1 and compared with those taken before the insult. After the last acquisition, rats were sacrificed and the infarct volume was determined via Nissl staining. The results obtained with micro-SPECT and micro-CT were compared with histology at the same time points. Mild hypothermia (33°C) was induced for 2 h, starting 20 min after the insult. RESULTS Brain damage was estimated using micro-SPECT and micro-CT and was reproducible with minimal interobserver variability. Normothermic stroke rats had reduced (99m)Tc-HMPAO uptake at 1 and 3 d after the insult, whereas hypothermia improved damage after stroke. These findings corroborate with histology at the same time points. At 1 wk after the insult, no reduction of radioactive uptake was observed in any treatment group. CONCLUSION Micro-SPECT and micro-CT allow quick and reproducible semiquantification of brain damage as an interesting alternative to histology to measure the extent of infarcted tissue in small animals after stroke.
Collapse
Affiliation(s)
- An-Gaëlle Ceulemans
- Department of Pharmaceutical Chemistry and Drug Analysis, FASC, Center for Neuroscience, Vrije Universiteit Brussel, Brussels, Belgium
| | | | | | | | | | | | | | | |
Collapse
|
13
|
Hayward NMEA, Yanev P, Haapasalo A, Miettinen R, Hiltunen M, Gröhn O, Jolkkonen J. Chronic hyperperfusion and angiogenesis follow subacute hypoperfusion in the thalamus of rats with focal cerebral ischemia. J Cereb Blood Flow Metab 2011; 31:1119-32. [PMID: 21081957 PMCID: PMC3070972 DOI: 10.1038/jcbfm.2010.202] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cerebral blood flow (CBF) is disrupted after focal ischemia in rats. We examined long-term hemodynamic and cerebrovascular changes in the rat thalamus after focal cerebral ischemia. Cerebral blood flow quantified by arterial spin labeling magnetic resonance imaging was decreased in the ipsilateral and contralateral thalamus 2 days after cerebral ischemia. Partial thalamic CBF recovery occurred by day 7, then the ipsilateral thalamus was chronically hyperperfused at 30 days and 3 months compared with its contralateral side. This contrasted with permanent hypoperfusion in the ipsilateral cortex. Angiogenesis was indicated by endothelial cell (RECA-1) immunohistochemistry that showed increased blood vessel branching in the ipsilateral thalamus at the end of the 3-month follow-up. Only transient thalamic IgG extravasation was observed, indicating that the blood-brain barrier was intact after day 2. Angiogenesis was preceded by transiently altered expression levels of cadherin family adhesion molecules, cadherin-7, protocadherin-1, and protocadherin-17. In conclusion, thalamic pathology after focal cerebral ischemia involved long-term hemodynamic changes and angiogenesis preceded by altered expression of vascular adhesion factors. Postischemic angiogenesis in the thalamus represents a novel type of remote plasticity, which may support removal of necrotic brain tissue and aid functional recovery.
Collapse
Affiliation(s)
- Nick M E A Hayward
- Department of Neurobiology, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | | | | | | | | | | | | |
Collapse
|
14
|
Antioxidant CR-6 protects against reperfusion injury after a transient episode of focal brain ischemia in rats. J Cereb Blood Flow Metab 2010; 30:638-52. [PMID: 19904289 PMCID: PMC2949133 DOI: 10.1038/jcbfm.2009.237] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Oxidative and nitrosative stress are targets for intervention after ischemia/reperfusion. The aim of this study was to explore the effect of CR-6, a vitamin-E analogue that is antioxidant and scavenger of nitrogen-reactive species. Sprague-Dawley rats had the middle cerebral artery (MCA) occluded either for 90 mins or permanently. Cortical perfusion was continuously monitored by laser-Doppler flowmetry. CR-6 (100 mg/kg) was administered orally either at 2 and 8 h after MCA occlusion, or at 2 h only. Infarct volume, neurological deficit, and signs of reperfusion injury were evaluated. CR-6 was detected in plasma and brain by HPLC. CR-6 reduced glutathione consumption in the ischemic brain and superoxide generation in the isolated MCA. CR-6 decreased infarct volume and attenuated the neurological deficit at 1 and 7 days after ischemia/reperfusion, but not after permanent ischemia. Immediately after reperfusion, cortical blood flow values returned to their baseline (+/-20%) in several animals, whereas others showed hyper-perfusion (>20% of baseline). Reactive hyperemia was associated with adverse events such as increased cortical BBB leakage, edema, protein nitrotyrosination, COX-2 expression, and neutrophil accumulation; and with a poorer outcome, and CR-6 attenuated these effects. In conclusion, oral CR-6 administration after transient ischemia protects the brain from reperfusion injury.
Collapse
|
15
|
Maddahi A, Edvinsson L. Cerebral ischemia induces microvascular pro-inflammatory cytokine expression via the MEK/ERK pathway. J Neuroinflammation 2010; 7:14. [PMID: 20187933 PMCID: PMC2837637 DOI: 10.1186/1742-2094-7-14] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Accepted: 02/26/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cerebral ischemia from middle cerebral artery wall (MCA) occlusion results in increased expression of cerebrovascular endothelin and angiotensin receptors and activation of the mitogen-activated protein kinase (MAPK) pathway, as well as reduced local cerebral blood flow and increased levels of pro-inflammatory mediators in the infarct region. In this study, we hypothesised that inhibition of the cerebrovascular inflammatory reaction with a specific MEK1/2 inhibitor (U0126) to block transcription or a combined receptor blockade would reduce infarct size and improve neurological score. METHODS Rats were subjected to a 2-hours middle cerebral artery occlusion (MCAO) followed by reperfusion for 48 hours. Two groups of treated animals were studied; (i) one group received intraperitoneal administration of a specific MEK1/2 inhibitor (U0126) starting at 0, 6, or 12 hours after the occlusion, and (ii) a second group received two specific receptor antagonists (a combination of the angiotensin AT1 receptor inhibitor Candesartan and the endothelin ETA receptor antagonist ZD1611), given immediately after occlusion. The middle cerebral arteries, microvessels and brain tissue were harvested; and the expressions of tumor necrosis factor-alpha (TNF-alpha), interleukin-1ss (IL-1ss), interleukin-6 (IL-6), inducible nitric oxide synthase (iNOS) and phosphorylated ERK1/2, p38 and JNK were analysed using immunohistochemistry. RESULTS We observed an infarct volume of 25 +/- 2% of total brain volume, and reduced neurological function 2 days after MCAO followed by 48 hours of recirculation. Immunohistochemistry revealed enhanced expression of TNF-alpha, IL-1ss, IL-6 and iNOS, as well as elevated levels of phosphorylated ERK1/2 in smooth muscle cells of ischemic MCA and in associated intracerebral microvessels. U0126, given intraperitoneal at zero or 6 hours after the ischemic event, but not at 12 hours, reduced the infarct volume (11.7 +/- 2% and 15 +/- 3%, respectively), normalized pERK1/2, and prevented elevation of the expressions of TNF-alpha IL-1ss, IL-6 and iNOS. Combined inhibition of angiotensin AT1 and endothelin ETA receptors decreased the volume of brain damaged (12.3 +/- 3; P < 0.05) but only slightly reduced MCAO-induced enhanced expression of iNOS and cytokines CONCLUSION The present study shows elevated microvascular expression of TNF-alpha, IL-1ss, IL-6 and iNOS following focal ischemia, and shows that this expression is transcriptionally regulated via the MEK/ERK pathway.
Collapse
Affiliation(s)
- Aida Maddahi
- Department of Internal Medicine, Institute of Clinical Sciences, Lund University, Sweden.
| | | |
Collapse
|
16
|
Hughes J, Beech J, Jones P, Wang D, Menon D, Baron J. Mapping selective neuronal loss and microglial activation in the salvaged neocortical penumbra in the rat. Neuroimage 2010; 49:19-31. [DOI: 10.1016/j.neuroimage.2009.08.047] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2009] [Revised: 07/24/2009] [Accepted: 08/17/2009] [Indexed: 11/24/2022] Open
|
17
|
Maddahi A, Chen Q, Edvinsson L. Enhanced cerebrovascular expression of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 via the MEK/ERK pathway during cerebral ischemia in the rat. BMC Neurosci 2009; 10:56. [PMID: 19497125 PMCID: PMC2700114 DOI: 10.1186/1471-2202-10-56] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2008] [Accepted: 06/04/2009] [Indexed: 12/30/2022] Open
Abstract
Background Cerebral ischemia is usually characterized by a reduction in local blood flow and metabolism and by disruption of the blood-brain barrier in the infarct region. The formation of oedema and opening of the blood-brain barrier in stroke is associated with enhanced expression of metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1). Results Here, we found an infarct volume of 24.8 ± 2% and a reduced neurological function after two hours of middle cerebral artery occlusion (MCAO), followed by 48 hours of recirculation in rat. Immunocytochemistry and confocal microscopy revealed enhanced expression of MMP-9, TIMP-1, and phosphorylated ERK1/2 in the smooth muscle cells of the ischemic MCA and associated intracerebral microvessels. The specific MEK1/2 inhibitor U0126, given intraperitoneal zero or 6 hours after the ischemic event, reduced the infarct volume significantly (11.8 ± 2% and 14.6 ± 3%, respectively; P < 0.05), improved neurological function, normalized expression of phosphorylated ERK1/2, and reduced expression of MMP-9 and TIMP-1 in the vessel walls. Administration of U0126 12 hours after MCAO did not alter the expression of MMP-9. Immunocytochemistry showed no overlap in expression between MMP-9/TIMP-1 and the astrocyte/glial cell marker GFAP in the vessel walls. Conclusion These data are the first to show that the elevated vascular expression of MMP-9 and TIMP-1, associated with breakdown of the blood-brain barrier following focal ischemia, are transcriptionally regulated via the MEK/ERK pathway.
Collapse
Affiliation(s)
- Aida Maddahi
- Department of Clinical Sciences, Division of Experimental Vascular Research, Lund University, Lund, Sweden.
| | | | | |
Collapse
|
18
|
Hutchison JS, Doherty DR, Orlowski JP, Kissoon N. Hypothermia therapy for cardiac arrest in pediatric patients. Pediatr Clin North Am 2008; 55:529-44, ix. [PMID: 18501753 DOI: 10.1016/j.pcl.2008.02.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Cardiac arrest is associated with high morbidity and mortality in children. Hypothermia therapy has theoretical benefits on brain preservation and has the potential to decrease morbidity and mortality in children following cardiac arrest. The American Heart Association guidelines recommend that it should be considered in children after cardiac arrest. Methods of inducing hypothermia include simple surface cooling techniques, intravenous boluses of cold saline, gastric lavage with ice-cold normal saline, and using the temperature control device with extracorporeal life support. We recommend further study before a strong recommendation can be made to use hypothermia therapy in children with cardiac arrest.
Collapse
Affiliation(s)
- James S Hutchison
- Department of Critical Care Medicine, University of Toronto and Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada.
| | | | | | | |
Collapse
|
19
|
Luo W, Wang Z, Li P, Zeng S, Luo Q. A modified mini-stroke model with region-directed reperfusion in rat cortex. J Cereb Blood Flow Metab 2008; 28:973-83. [PMID: 18073774 DOI: 10.1038/sj.jcbfm.9600591] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Mini-ischemia localized into a specific brain area has promoted understanding of the mechanisms underlying brain recovery in stroke. However, the conventional mini-stroke model adopted permanent arterial ligations but lacked controllable reperfusion, which is crucial for the outcome of delayed functional recovery. In this study, we devised a new rat mini-stroke model in which the vascular ligations can be easily reversed to induce targeted reperfusion. Specifically, a flexible ring was incorporated into the conventional small arterial ligations to tighten the ligating loops and facilitate cutting the ligatures for sufficient reperfusion afterwards. The distribution of cerebral blood flow was explored directly through a cranial window using laser speckle contrast imaging. A distinct ischemic core, which well fits the profile of the ligated ring, was bordered by a penumbral zone and then together surrounded by nonischemic tissue immediately after the arterial ligations involving the ring. After cutting the ligatures, post-recanalization hyperperfusion occurred in the previous ischemic core and to a greater extent at 24 h after reperfusion. In contrast, recirculation of common carotid artery in the conventional mini-stroke model hardly altered hypoperfusion status within the ischemic core. Evidence from two kinds of control groups indicated that the ring might produce a compression effect on the underlying cortex and then contribute to the more highly localized infarct that was identified by triphenyltetrazolium chloride staining. Our data suggest that this model provides opportunities for investigating the neurovascular dynamics in acute stroke and rehabilitation, especially with emerging optical imaging techniques.
Collapse
Affiliation(s)
- Weihua Luo
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, PR China
| | | | | | | | | |
Collapse
|
20
|
Koh PO, Cho JH, Won CK, Lee HJ, Sung JH, Kim MO. Estradiol attenuates the focal cerebral ischemic injury through mTOR/p70S6 kinase signaling pathway. Neurosci Lett 2008; 436:62-6. [PMID: 18378082 DOI: 10.1016/j.neulet.2008.02.061] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2007] [Revised: 02/16/2008] [Accepted: 02/27/2008] [Indexed: 01/23/2023]
Abstract
We previously showed that estradiol prevents neuronal cell death through the activation of Akt and its downstream targets Bad and FKHR. This study investigated whether estradiol modulates the survival pathway through other downstream targets of Akt, including mammalian target of rapamycin (mTOR) and p70S6 kinase. It is known that mTOR is a downstream target of Akt and a central regulator of protein synthesis, cell growth, and cell cycle progression. Adult female rats were ovariectomied and treated with estradiol prior to middle cerebral artery occlusion (MCAO). Brains were collected 24h after MCAO and infarct volumes were analyzed. We confirmed that estradiol significantly reduces infarct volume and decreases the number of positive cells for TUNEL staining in the cerebral cortex. Brain injury-induced a decrease in phospho-mTOR and phospho-p70S6 kinase. Estradiol prevented the injury-induced decrease in Akt activation and phosphorylation of mTOR and p70S6 kinases, and the subsequent decrease in S6 phosphorylation. Our findings suggest that estradiol plays a potent protective role against brain injury by preventing the injury-induced decrease of mTOR and p70S6 kinase phosphorylation.
Collapse
Affiliation(s)
- Phil-Ok Koh
- Department of Anatomy, College of Veterinary Medicine, Institute of Agriculture and Life Science, Gyeongsang National University, 900 Gajwa-dong, Jinju 660-701, South Korea.
| | | | | | | | | | | |
Collapse
|
21
|
Parry-Jones AR, Liimatainen T, Kauppinen RA, Gröhn OH, Rothwell NJ. Interleukin-1 exacerbates focal cerebral ischemia and reduces ischemic brain temperature in the rat. Magn Reson Med 2008; 59:1239-49. [DOI: 10.1002/mrm.21531] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
22
|
Mörtberg E, Cumming P, Wiklund L, Wall A, Rubertsson S. A PET study of regional cerebral blood flow after experimental cardiopulmonary resuscitation. Resuscitation 2007; 75:98-104. [PMID: 17499906 DOI: 10.1016/j.resuscitation.2007.03.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2006] [Revised: 03/26/2007] [Accepted: 03/30/2007] [Indexed: 10/23/2022]
Abstract
Cerebral blood flow (CBF) during cardiopulmonary resuscitation and after restoration of spontaneous circulation (ROSC) from cardiac arrest has previously been measured with the microspheres and laser Doppler techniques. We used positron emission tomography (PET) with [15O]--water to map the haemodynamic changes after ROSC in nine young pigs. After the baseline PET recording, ventricular fibrillation of 5 min duration was induced, followed by closed-chest cardiopulmonary resuscitation (CPR) in conjunction with IV administration of three bolus doses of adrenaline (epinephrine). After CPR, external defibrillatory shocks were applied to achieve ROSC. CBF was measured at intervals during 4h after ROSC. Relative to the mean global CBF at baseline (32+/-5 ml hg(-1)min(-1)), there was a substantial global increase in CBF at 10 min, especially in the diencephalon. This was followed by an interval of cortical hypoperfusion and a subsequent gradual return to baseline values.
Collapse
Affiliation(s)
- Erik Mörtberg
- Department of Surgical Sciences-Anesthesiology and Intensive Care, Uppsala University, Uppsala, Sweden.
| | | | | | | | | |
Collapse
|
23
|
Nakai A. Role of mitochondrial permeability transition in the immature brain following intrauterine ischemia. J NIPPON MED SCH 2007; 74:190-201. [PMID: 17625367 DOI: 10.1272/jnms.74.190] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Recirculation following 30 minutes of intrauterine ischemia due to uterine artery occlusion has previously been found to be accompanied by delayed deterioration of the cellular bioenergetic state and of mitochondrial function in the fetal rat brain. The objective of this study was to assess whether the delayed deterioration is due to the activation of mitochondrial permeability transition (MPT), which is observed ultrastructurally as mitochondrial swelling. The respiratory activities and ultrastructure of isolated mitochondria and the cellular bioenergetic state in the fetal rat brain were examined at the end of 30 minutes of intrauterine ischemia and after 1, 2, 3 or 4 hours of recirculation. Cyclosporin A (CsA), a potent and specific MPT blocker, or vehicle was given 1 hour after recirculation. In the vehicle-treated animals, the transient ischemia was associated with a delayed deterioration of the cellular bioenergetic state and mitochondrial activities 4 hours of recirculation. The number of swollen mitochondria increased markedly after 4 hours of recirculation. Both the deterioration and swelling were prevented by CsA. The present study indicates that treatment with CsA improves recovery of energy metabolism and inhibits mitochondrial swelling following transient intrauterine ischemia in the fetal brain. The results suggest that mitochondria and MPT may be involved in the development of ischemic brain damage in the immature rat.
Collapse
Affiliation(s)
- Akihito Nakai
- Department of Female Reproductive and Developmental Medicine, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan.
| |
Collapse
|
24
|
Koh PO. Estradiol prevents the injury-induced decrease of 90 ribosomal S6 kinase (p90RSK) and Bad phosphorylation. Neurosci Lett 2007; 412:68-72. [PMID: 17196335 DOI: 10.1016/j.neulet.2006.10.060] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2006] [Revised: 10/14/2006] [Accepted: 10/17/2006] [Indexed: 12/20/2022]
Abstract
Estradiol prevents neuronal cell death through the activation of cell survival signals and the inhibition of apoptotic signals. This study investigated whether estradiol modulates the anti-apoptotic signal through the activation of Raf-MEK-ERK and its downstream targets, including 90 ribosomal S6 kinase (p90RSK) and Bad. Adult female rats were ovariectomied and treated with estradiol prior to middle cerebral artery occlusion (MCAO). Brains were collected 24h after MCAO and infarct volumes were analyzed. We confirmed that estradiol significantly reduces infarct volume and decreases the positive cells of TUNEL staining in the cerebral cortex. Estradiol prevents the injury-induced decrease of Raf-1, MEK1/2, and ERK1/2 phosphorylation. Also, it inhibits the injury-induced decrease of p90RSK and Bad phosphorylation. Further, in the presence of estradiol, the interaction of phospho-Bad and 14-3-3 increased, compared with that of oil-treated animals. Our findings suggest that estradiol prevents cell death due to brain injury and that Raf-MEK-ERK cascade activation and its downstream targets, p90RSK, Bad phosphorylation by estradiol mediated these protective effects.
Collapse
Affiliation(s)
- Phil Ok Koh
- Department of Anatomy, College of Veterinary Medicine and Research Institute of Life Science, Gyeongsang National University, 900 Gajwa-dong, Jinju 660-701, South Korea.
| |
Collapse
|
25
|
Sánchez A, Fernández N, Monge L, Salcedo A, Climent B, Luis García-Villalón A, Diéguez G. Goat cerebrovascular reactivity to ADP after ischemia-reperfusion. Role of nitric oxide, prostanoids and reactive oxygen species. Brain Res 2006; 1120:114-23. [PMID: 16996044 DOI: 10.1016/j.brainres.2006.08.061] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2006] [Revised: 06/19/2006] [Accepted: 08/17/2006] [Indexed: 10/24/2022]
Abstract
To analyze the cerebrovascular effects of ischemia-reperfusion, cerebrovascular reactivity to ADP was studied after inducing 60-min occlusion followed by 60-min reperfusion of the left middle cerebral artery (MCA) in anesthetized goats. In 12 goats, at the end of reperfusion, left MCA resistance was decreased by 19%, and reactive hyperemia to 5- and 10-s occlusions as well as the cerebral vasodilatation to ADP (0.03-0.3 microg) but not to sodium nitroprusside (0.3-3 microg) was decreased. In 28 animals, killed at the end of reperfusion, segments 3-mm long were obtained from the left (ischemic) and right (control) MCA, prepared for isometric tension recording, and precontracted with the thromboxane A2 analogue U46619. The relaxation to ADP (10(-8) to 10(-5) M) but not to sodium nitroprusside (10(-8) to 10(-4) M) was lower in ischemic arteries. L-NAME (inhibitor of nitric oxide synthesis, 10(-4) M), charybdotoxin (10(-7) M)+apamin (10(-6) M) (blockers of KCa), or catalase (1000 U/ml) reduced the relaxation to ADP only in control arteries. Charybdotoxin+apamin further augmented the L-NAME-induced reduction in the relaxation to ADP in control arteries. The inhibitor of cyclooxygenase meclofenamate (10(-5) M) increased the relaxation to ADP only in ischemic arteries. The superoxide dismutase mimetic tiron (10(-2) M) increased the ADP-induced relaxation only in ischemic arteries. Therefore, it is suggested that ischemia-reperfusion produces cerebrovascular endothelial dysfunction, which may be associated with decreased nitric oxide bioavailability, decreased release of an EDHF, and increased production of vasoconstrictor prostanoids. All these alterations may be related in part with an increased production of superoxide anion.
Collapse
Affiliation(s)
- Ana Sánchez
- Departamento de Fisiología, Facultad de Medicina, Universidad Autónoma, Arzobispo Morcillo, 2, 28029 Madrid, Spain
| | | | | | | | | | | | | |
Collapse
|
26
|
Koh PO, Won CK, Cho JH. Estradiol prevents the injury-induced decrease of Akt/glycogen synthase kinase 3β phosphorylation. Neurosci Lett 2006; 404:303-8. [PMID: 16815634 DOI: 10.1016/j.neulet.2006.06.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2006] [Revised: 06/07/2006] [Accepted: 06/07/2006] [Indexed: 10/24/2022]
Abstract
Estradiol prevents neuronal cell death through the activation of cell survival signals and the inhibition of apoptotic signals. This study investigated whether estradiol modulates the anti-apoptotic signal through the phosphorylation of Akt and its downstream target, glycogen synthase kinase 3beta (GSK3beta). Adult female rats were ovariectomized and treated with estradiol prior to middle cerebral artery occlusion (MCAO). Brains were collected 24 h after MCAO and infarct volumes were analyzed. Estradiol administration significantly reduced infarct volume and decreased the positive cells of TUNEL staining in the cerebral cortex. Potential activation was measured by phosphorylation of Akt at Ser(473) and GSK3beta at Ser(9) using Western blot analysis and immunohistochemistry. Estradiol prevented the injury-induced decrease of pAkt and pGSK3beta. Furthermore, pretreatment with estradiol decreased glutamate toxicity-induced cell death in a hippocampal cell line (HT22). Also, estradiol prevented the glutamate toxicity-induced decrease of pAkt and pGSK3beta in HT22 cells. Our findings suggest that estradiol plays a potent protective role against brain injury and that phosphorylation of Akt and GSK3beta by estradiol mediated these protective effects.
Collapse
Affiliation(s)
- Phil Ok Koh
- Department of Anatomy, College of Veterinary Medicine, Research Institute of Life Science, Gyeongsang National University, 900 Gajwa-dong, Jinju, South Korea.
| | | | | |
Collapse
|
27
|
Xu Z, Croslan DR, Harris AE, Ford GD, Ford BD. Extended therapeutic window and functional recovery after intraarterial administration of neuregulin-1 after focal ischemic stroke. J Cereb Blood Flow Metab 2006; 26:527-35. [PMID: 16136057 DOI: 10.1038/sj.jcbfm.9600212] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We have previously shown that neuregulin-1 (NRG-1) protects neurons from ischemic brain injury if administered before focal stroke. Here, we examined the therapeutic window and functional recovery after NRG-1 treatment in rats subjected to 90 mins of middle cerebral artery occlusion (MCAO) and 24 h of reperfusion. Neuregulin-1 (2.5 microg/kg [corrected] bolus, 1.25 microg/kg/min [corrected] infusion) reduced infarct volume by 89.2%+/-41.9% (mean+/-s.d.; n=8; P<0.01) if administered immediately after the onset of reperfusion. Neuroprotection was also evident if NRG-1 was administered 4 h (66.4%+/-52.6%; n=7; P<0.01) and 12 h (57.0%+/-20.8%; n=8; P<0.01) after reperfusion. Neuregulin-1 administration also resulted in a significant improvement of functional neurologic outcome compared with vehicle-treated animals (32.1%+/-5.7%; n=9; P<0.01). The neuroprotective effect of the single administration of NRG-1 was seen as long as 2 weeks after treatment. Neurons labeled with the neurodegeneration marker dye Fluoro-JadeB were observed after MCAO in the cortex, but the numbers were significantly reduced after NRG-1 treatment. These results indicate that NRG-1 is a potent neuroprotective compound with an extended therapeutic window that has practical therapeutic potential in treating individuals after ischemic brain injury.
Collapse
Affiliation(s)
- Zhenfeng Xu
- Department of Anatomy and Neurobiology, Neuroscience Institute, Morehouse School of Medicine, Atlanta, Georgia 30310, USA
| | | | | | | | | |
Collapse
|
28
|
Won CK, Ji HH, Koh PO. Estradiol prevents the focal cerebral ischemic injury-induced decrease of forkhead transcription factors phosphorylation. Neurosci Lett 2006; 398:39-43. [PMID: 16423457 DOI: 10.1016/j.neulet.2005.12.060] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2005] [Revised: 12/21/2005] [Accepted: 12/22/2005] [Indexed: 10/25/2022]
Abstract
Estradiol prevents neuronal cell death through the inhibition of apoptotic signals. This study investigated whether estradiol modulates the anti-apoptotic signal through the activation of Akt and its downstream targets, including forkhead transcription factors FKHR and FHKRL1. Adult female rats were ovariectomied and treated with estradiol prior to middle cerebral artery occlusion (MCAO). Brains were collected 24 h after MCAO and infarct volumes were analyzed. Estradiol administration significantly reduced infarct volume and decreased the positive cells of TUNEL staining in the cerebral cortex. Potential activation was measured by phosphorylation of Akt at Ser473, pFKHR at Ser256, and pFKHRL1 at Thr32 using Western blot analysis and immunohistochemistry. Estradiol prevents the injury-induced decrease of pAkt, pFKHR, and pFKHRL1. Further, in the presence of estradiol, the interaction of pFKHRL1 and 14-3-3 increased, compared to that of oil-treated animals. Our findings suggest that estradiol plays a potent protective role against brain injury and that Akt activation and FKHR phosphorylation by estradiol mediated these protective effects.
Collapse
Affiliation(s)
- Chung Kil Won
- Department of Anatomy, College of Veterinary Medicine and Institute of Animal Medicine, Gyeongsang National University, 900 Gajwa-dong, Jinju 660-701, South Korea
| | | | | |
Collapse
|
29
|
Won CK, Kim MO, Koh PO. Estrogen Modulates Bcl-2 Family Proteins in Ischemic Brain Injury. J Vet Med Sci 2006; 68:277-80. [PMID: 16598173 DOI: 10.1292/jvms.68.277] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Estradiol acts as a neuroprotective factor against brain injury. This study investigated whether estradiol modulates the Bcl-2 family proteins in ischemic brain injury. Adult female rats were ovariectomized and treated with estradiol prior to middle cerebral artery occlusion (MCAO). Brains were collected 24 hr after MCAO, and infarct volumes were analyzed. Estradiol significantly reduces the infarct volume and decreases the positive cells of TUNEL staining in cerebral cortex. In ischemic cerebral cortex, the level of Bcl-2 was decreased, and the level of Bax was significantly increased. Estradiol prevents the injury-induced decrease of Bcl-2 and increase of Bax. In conclusion, our findings suggest that estradiol plays a potent protective role in brain injury through the regulation of Bcl-2 family proteins.
Collapse
Affiliation(s)
- Chung-Kil Won
- Department of Anatomy, College of Veterinary Medicine and Institute of Animal Medicine, Gyeongsang National University, Jinju 660-701, South Korea
| | | | | |
Collapse
|
30
|
Won CK, Ha SJ, Noh HS, Kang SS, Cho GJ, Choi WS, Koh PO. Estradiol prevents the injury-induced decrease of Akt activation and Bad phosphorylation. Neurosci Lett 2005; 387:115-9. [PMID: 16087293 DOI: 10.1016/j.neulet.2005.07.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2005] [Revised: 07/14/2005] [Accepted: 07/14/2005] [Indexed: 10/25/2022]
Abstract
Estradiol prevents neuronal cell death through the inhibition of apoptotic signals and the activation of cell survival signals. This study investigated whether estradiol modulates the anti-apoptotic signal through the activation of Akt and its downstream targets, including Bad, Bcl-x(L), and 14-3-3. Adult female rats were ovariectomied and treated with estradiol prior to middle cerebral artery occlusion (MCAO). Brains were collected 24 h after MCAO and infarct volumes were analyzed. We confirmed that estradiol significantly reduces infarct volume and decreases the positive cells of TUNEL staining in the cerebral cortex. Potential activation was measured by phosphorylation of Akt at Ser473 and Bad at Ser136 using Western blot analysis. Estradiol prevents the injury-induced decrease of pAkt, pBad, and Bcl-x(L). Further, in the presence of estradiol, the interaction of pBad and 14-3-3 increased, compared to that of oil-treated animals. Our findings suggest that estradiol prevents cell death due to brain injury and that Akt activation and Bad phosphorylation by estradiol mediated these protective effects.
Collapse
Affiliation(s)
- Chung Kil Won
- Department of Anatomy, College of Veterinary Medicine and Institute of Animal Science, Gyeongsang National University, Chinju 660-701, South Korea
| | | | | | | | | | | | | |
Collapse
|
31
|
Lee DR, Helps SC, Gibbins IL, Nilsson M, Sims NR. Losses of NG2 and NeuN immunoreactivity but not astrocytic markers during early reperfusion following severe focal cerebral ischemia. Brain Res 2003; 989:221-30. [PMID: 14556944 DOI: 10.1016/s0006-8993(03)03373-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The ability of glia to recover essential functions following a period of focal cerebral ischemia is likely to be one important factor influencing the severity of tissue damage that subsequently develops. In this study, we have compared changes in immunoreactivity of markers specific for astrocytes, NG2-positive glia and neurons in tissue subregions during early reperfusion following 3 h of middle cerebral artery occlusion to provide insights into possible differential susceptibility of these cell populations. Under the conditions used, infarction ultimately encompasses most of the perfusion territory of the occluded artery. Nonetheless, alterations in immunoreactivity during the first 3 h of recirculation were restricted to brain regions that had been subjected to severe ischemia. In the striatum, cellular immunoreactivity for NG2 and neuronal markers, NeuN and microtubule-associated protein 2, was greatly reduced by 1 h of reperfusion and declined further at 3 h. NG2 labeling of blood vessels in the striatum appeared post-ischemically, mimicking expression of this protein during development. Less severe changes were seen in the neuronal markers in overlying cerebral cortex. In contrast to the losses of other cellular proteins, immunoreactivity for the astrocytic marker, glial fibrillary acidic protein, was preserved in all tissue that had been subjected to severe ischemia and labeling of another astrocytic protein, glutamine synthetase, was increased by 3 h of reperfusion. These findings provide the first evidence of marked sensitivity of NG2-immunoreactivity to severe ischemia and suggest a greater initial resistance of astrocytes compared with neurons and NG2-positive glia to ischemia-reperfusion damage.
Collapse
Affiliation(s)
- Diane R Lee
- Centre for Neuroscience and Department of Medical Biochemistry, Flinders University, GPO Box 2100, Adelaide, South Australia 5001, Australia.
| | | | | | | | | |
Collapse
|
32
|
Gervitz LM, Davies DG, Omidvar K, Fowler JC. The effect of acute hypoxemia and hypotension on adenosine-mediated depression of evoked hippocampal synaptic transmission. Exp Neurol 2003; 182:507-17. [PMID: 12895463 DOI: 10.1016/s0014-4886(03)00160-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The present study was designed to investigate the relative contributions of arterial P(O(2)), local cerebral blood flow, and oxygen delivery to the adenosine A(1) receptor-mediated depression of evoked synaptic transmission recorded in the rat hippocampus. Urethane-anesthetized rats were given a unilateral common carotid artery occlusion and then placed in a stereotaxic apparatus for stimulation and recording of bilateral hippocampal field excitatory postsynaptic potentials (fEPSPs). Arterial blood gases, mean arterial blood pressure (MAP), and bilateral hippocampal blood flow (HBF) were also measured. Arterial P(O(2)), HBF, and oxygen delivery were manipulated using normoxic hypotension, hypoxic hypotension, and hypoxic normotension. Both hypoxic hypotension and normoxic hypotension resulted in decreased HBF, decreased oxygen delivery, and a depression of the evoked fEPSP limited to the hippocampus ipsilateral to the occlusion. The enhanced HBF and oxygen delivery associated with increased MAP resulted in a restoration and maintenance of hippocampal fEPSPs despite sustained hypoxemia. The adenosine A(1) receptor-mediated depression of the fEPSP was more strongly correlated with changes in HBF and oxygen delivery than with arterial P(O(2)). We propose that adenosine plays an important role mediating the depression of neuronal activity associated with reduced oxygen delivery characteristically observed in ischemic brain tissue.
Collapse
Affiliation(s)
- L M Gervitz
- Department of Physiology, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA.
| | | | | | | |
Collapse
|
33
|
Schaafsma A, de Jong BM, Bams JL, Haaxma-Reiche H, Pruim J, Zijlstra JG. Cerebral perfusion and metabolism in resuscitated patients with severe post-hypoxic encephalopathy. J Neurol Sci 2003; 210:23-30. [PMID: 12736083 DOI: 10.1016/s0022-510x(03)00063-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Positron emission tomography (PET) was used for the study of regional cerebral perfusion and metabolism in eight patients with severe post-hypoxic encephalopathy, caused by cardiac arrest and resulting in a coma lasting for at least 24 h. Using this method, we aimed to identify regional vulnerability, which was hypothesized to provide (i) insight in pathogenic mechanisms and (ii) early prognostic parameters. On day 1 post-resuscitation, 18-Fluor deoxyglucose ([F18]-FDG) indicated a marked decrease of cerebral metabolic activity. Gray matter glucose consumption was 54% of normal values, whereas white matter uptake was 70% of normal. Regional differences followed a pattern of neuronal density rather than specific patterns of functionally or biochemically defined regions or of vascular territories. In contrast to [F18]-FDG, the distribution of 15-oxygen labeled water ([O-15]-water) showed a better demarcation between gray and white matter, whereas focal deficit was not observed. In some patients, hyperperfusion relative to regional glucose consumption was observed in the occipital poles and basal ganglia. This suggests loss of vascular tone, i.e. vascular paralysis, in the basilar artery territory. CT and MRI scanning did not show any major change with respect to the hypoxic injury. In the small group studied, all patients had a poor outcome. The comparison between survivors and nonsurvivors did not reveal obvious differences in PET data, suggesting that this technique does not provide major prognostic clues adding to the prognostic information derived from serial neurological assessment in the restricted patient group characterized by prolonged coma.
Collapse
Affiliation(s)
- A Schaafsma
- Department of Neurology, University Hospital Groningen, P.O. Box 30.001, 9700 RB, Groningen, The Netherlands
| | | | | | | | | | | |
Collapse
|
34
|
Kametsu Y, Osuga S, Hakim AM. Apoptosis occurs in the penumbra zone during short-duration focal ischemia in the rat. J Cereb Blood Flow Metab 2003; 23:416-22. [PMID: 12679718 DOI: 10.1097/01.wcb.0000052281.23292.7c] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
To investigate the appearance of apoptosis in short-duration focal ischemia, the authors induced left middle cerebral artery (MCA) occlusion in male rats by insertion of an intraluminal suture. The total number of apoptotic cells was determined by hematoxylin-eosin staining and TUNEL labeling and confirmed by gel electrophoresis. The data indicate that the total number of apoptotic cells increased with ischemia duration (P = 0.0006), with most apoptotic cells located in the striatum of the ischemic hemisphere. As the duration of ischemia lengthened, necrosis became more prevalent and apoptosis receded to the periphery of the infarct. Using iodo[14C]-antipyrine to correlate the distribution of apoptosis to regional CBF (rCBF), the authors found that rCBF in the ischemic dorsolateral striatum was compatible with penumbra flow and significantly lower than the ventromedial striatum and frontoparietal cortex. This difference disappeared after 45 minutes of reperfusion. The authors conclude that focal ischemia of short duration results in changes compatible with apoptosis in regions of low rCBF, and this can occur without necrosis. This model is relevant to transient ischemic attack in the human and may suggest that, in addition to being a harbinger of stroke, transient ischemic attacks may cause histopathologic changes not yet clinically detectable.
Collapse
Affiliation(s)
- Yutaka Kametsu
- Department of Neurology, School of Medicine, University of Tokai Isehara, Kanagawa, Japan
| | | | | |
Collapse
|
35
|
Lauer KK, Shen H, Stein EA, Ho KC, Kampine JP, Hudetz AG. Focal cerebral ischemia in rats produced by intracarotid embolization with viscous silicone. Neurol Res 2002; 24:181-90. [PMID: 11877903 DOI: 10.1179/016164102101199594] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Many factors contribute to the severity of neuronal cell death and the functional outcome in stroke. We describe an embolic model of focal cerebral ischemia in the rat that does not require craniotomy and is compatible with continuous measurement of regional CBF using multichannel laser Doppler flow (LDF) technique. Either a 22 microliters (large lesion) or 11 microliters (small lesion) bolus of viscous silicone was injected cephalad into the internal carotid artery. Upon injection, LDF decreased abruptly, most severely in the parietal cortex (-74% +/- 5%) in the large lesion and in the occipital cortex (-69% +/- 10%) in the small lesion model. Over the first hour, post-embolization LDF improved in most areas (e.g. -48% +/- 9% parietal, large lesion) but declined in the small lesion group in the occipital region (-81% +/- 8%). CBF measured by [C]14-IAP autoradiography 1 h post-embolization in the large lesion model demonstrated near-hemispheric ischemia (70% of hemisphere) with sparing of cingulate cortex. Autoradiography demonstrated that ischemia in the small lesion was largely cortical. Light microscopy of brains embolized with 11 microliters of dyed silicone showed filling of pial vessels with no silicone in the Circle of Willis or parenchyma. No animals in the large lesion group survived 24 h. Thirteen of 15 animals in the small lesion group survived for two weeks with resolution of initial hemiplegia, ocular asymmetry and weight loss. Hematoxylin-eosin staining two weeks post-embolization showed signs of severe hypoxia and infarction. In conclusion, the intracarotid silicone embolization technique produces a titrable, reproducible permanent ischemic injury by blocking perfusion in the pial circulation, and is amenable to multisite monitoring with laser Doppler flowmetry. The smaller embolus produces cortical infarction with high rate of survival and neurological recovery.
Collapse
Affiliation(s)
- Kathryn K Lauer
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, USA.
| | | | | | | | | | | |
Collapse
|
36
|
Pinard E, Nallet H, MacKenzie ET, Seylaz J, Roussel S. Penumbral microcirculatory changes associated with peri-infarct depolarizations in the rat. Stroke 2002; 33:606-12. [PMID: 11823677 DOI: 10.1161/hs0202.102738] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE This study was designed to investigate the influence of peri-infarct depolarization elicited by occlusion of the middle cerebral artery on the dynamics of the microcirculation. METHODS The microcirculation in the frontoparietal cortex of 9 rats was visualized in real time through a closed cranial window with the use of laser-scanning confocal fluorescence microscopy combined with intravenous fluorescein isothiocyanate (FITC)-dextran and FITC-labeled erythrocytes. The direct current potential/electrocorticogram was continuously monitored. Intraluminal focal ischemia was induced for 2 hours in 6 rats anesthetized with halothane and mechanically ventilated. Reperfusion was monitored for 1 hour. Three rats underwent sham operation. Brains were removed 24 hours after occlusion and processed for histology. RESULTS In control conditions, the velocity of fluorescent erythrocytes through capillaries was 0.51+/-0.19 mm/s (mean+/-SD), and the diameter of the arterioles studied was 33+/-12 microm. Under ischemia, erythrocyte velocity through capillaries was significantly decreased to 0.33+/-0.14 mm/s, while arteriole diameter did not change significantly. During spontaneous peri-infarct depolarizations, arteriole diameter was significantly increased (119+/-23% of baseline), while capillary erythrocyte velocity was further decreased by 14+/-34%. The direction of arteriolar blood flow episodically and transiently reversed during approximately half of the peri-infarct depolarizations. The decrease in capillary erythrocyte velocity was more pronounced (23+/-37%) in these cases. After reperfusion, the microcirculatory variables rapidly returned to baseline. All rats in the ischemic group had infarcts 24 hours after occlusion. CONCLUSIONS Peri-infarct depolarization has an adverse influence on penumbral microcirculation, reducing capillary perfusion by erythrocytes, despite dilatation of arterioles. These findings suggest that a steal phenomenon contributes to the deleterious effect of these depolarizations.
Collapse
Affiliation(s)
- Elisabeth Pinard
- Laboratoire de Recherches Cérébrovasculaires, CNRS UPR 646, Université Paris 7, IFR 6, Paris, France.
| | | | | | | | | |
Collapse
|
37
|
Yang SH, Perez E, Cutright J, Liu R, He Z, Day AL, Simpkins JW. Testosterone increases neurotoxicity of glutamate in vitro and ischemia-reperfusion injury in an animal model. J Appl Physiol (1985) 2002; 92:195-201. [PMID: 11744660 DOI: 10.1152/jappl.2002.92.1.195] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Increasing evidence has demonstrated striking sex differences in the outcome of neurological injury. Whereas estrogens contribute to these differences by attenuating neurotoxicity and ischemia-reperfusion injury, the effects of testosterone are unclear. The present study was undertaken to determine the effects of testosterone on neuronal injury in both a cell-culture model and a rodent ischemia-reperfusion model. Glutamate-induced HT-22 cell-death model was used to evaluate the effects of testosterone on cell survival. Testosterone was shown to significantly increase the toxicity of glutamate at a 10 microM concentration, whereas 17beta-estradiol significantly attenuated the toxicity at the same concentration. In a rodent stroke model, ischemia-reperfusion injury was induced by temporal middle cerebral artery occlusion (MCAO) for 1 h and reperfusion for 24 h. To avoid the stress-related testosterone reduction, male rats were castrated and testosterone was replaced by testosterone pellet implantation. Testosterone pellets were removed at 1, 2, 4, or 6 h before MCAO to determine the duration of acute testosterone depletion effects on infarct volume. Ischemic lesion volume was significantly decreased from 239.6 +/- 25.9 mm(3) in control to 122.5 +/- 28.6 mm(3) when testosterone pellets were removed at 6 h before MCAO. Reduction of lesion volume was associated with amelioration of the hyperemia during reperfusion. Our in vitro and in vivo studies suggest that sex differences in response to brain injury are partly due to the consequence of damaging effects of testosterone.
Collapse
Affiliation(s)
- Shao-Hua Yang
- Department of Pharmacology and Neuroscience, Health Science Center at Fort Worth, University of North Texas, Fort Worth, Texas 76107, USA
| | | | | | | | | | | | | |
Collapse
|
38
|
Wise PM, Dubal DB, Wilson ME, Rau SW, Böttner M, Rosewell KL. Estradiol is a protective factor in the adult and aging brain: understanding of mechanisms derived from in vivo and in vitro studies. BRAIN RESEARCH. BRAIN RESEARCH REVIEWS 2001; 37:313-9. [PMID: 11744096 DOI: 10.1016/s0165-0173(01)00136-9] [Citation(s) in RCA: 165] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We have shown that 17beta-estradiol exerts profound protective effects against stroke-like ischemic injury in female rats. These effects are evident using physiological levels of estradiol replacement in ovariectomized rats and require hormone treatment prior to the time of injury. The protective actions of estradiol appear to be most prominent in the cerebral cortex, where cell death is not apparent until at least 4 h after the initiation of ischemic injury and where cell death is thought to be apoptotic in nature. Middle-aged rats remain equally responsive to the protective actions of estradiol. The maintenance of responsiveness of the cerebral cortex to the neuroprotective actions of estradiol was unexpected since responsiveness of the hypothalamus to estradiol decreases dramatically by the time animals are middle-aged. We believe that the protective actions of estradiol require the estrogen receptor-alpha, since estradiol does not protect in estrogen receptor-alpha knockout mice. We have also implemented a method of culturing cerebral cortical explants to assess the protective effects of estradiol in vitro. This model exhibits remarkable parallelisms with our in vivo model of brain injury. We have found that 17beta-estradiol decreases the extent of cell death and that this protective effect requires hormone pretreatment. Finally, 17alpha-estradiol, which does not interact effectively with the estrogen receptor, does not protect; and addition of ICI 182,780, an estrogen receptor antagonist, blocks the protective actions of estradiol. We have begun to explore the molecular and cellular mechanisms of estradiol-mediated protection. In summary, our findings demonstrate that estradiol exerts powerful protective effects both in vivo and in vitro and suggest that these actions are mediated by estrogen receptors.
Collapse
Affiliation(s)
- P M Wise
- Department of Physiology, University of Kentucky, College of Medicine, 800 Rose Street, Lexington, KY 40536-0298, USA.
| | | | | | | | | | | |
Collapse
|
39
|
Biernaskie J, Corbett D, Peeling J, Wells J, Lei H. A serial MR study of cerebral blood flow changes and lesion development following endothelin-1-induced ischemia in rats. Magn Reson Med 2001; 46:827-30. [PMID: 11590661 DOI: 10.1002/mrm.1263] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The vasoconstrictive peptide endothelin-1 (ET-1) has been used previously to transiently occlude the middle cerebral artery (MCA) in rats. However, the duration of the resulting reduction in cerebral blood flow (CBF) and the reperfusion characteristics are poorly understood. In this study perfusion and T(2)-weighted MRI were used together with histology to characterize the cerebral perfusion dynamics and lesion development following ET-1 injection. Twenty-two rats received an intracerebral injection of ET-1 adjacent to the MCA. CBF was reduced to 30-50% of control levels, and a significant reduction persisted for 16 h in the cortex and 7 h in the striatum. The lesion size measured by T(2)-weighted imaging at 48 h correlated with the final infarct size measured by histology at 7 d. The sustained reduction in CBF and the gradual development of the ischemic lesion resemble human stroke evolution, suggesting that this model may be useful for evaluating therapeutic agents, particularly when treatment is delayed.
Collapse
Affiliation(s)
- J Biernaskie
- Division of Basic Medical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
| | | | | | | | | |
Collapse
|
40
|
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]
|
41
|
Kettunen MI, Gröhn OH, Lukkarinen JA, Vainio P, Silvennoinen MJ, Kauppinen RA. Interrelations of T(1) and diffusion of water in acute cerebral ischemia of the rat. Magn Reson Med 2000; 44:833-9. [PMID: 11108619 DOI: 10.1002/1522-2594(200012)44:6<833::aid-mrm3>3.0.co;2-f] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Interrelation of T(1) and diffusion of water was studied in rat models of acute global and focal cerebral ischemia. Cortical T(1), as quantified with an inversion recovery method, increased by 4-7% within a few minutes of global ischemia at 4.7 and 9.4 T, but a significantly smaller change was detected at 1.5 T. The initial T(1) change occurred within seconds of cardiac arrest, much earlier than the extensive diffusion drop after 1-2 min. Thus, the initial increase in T(1) upon acute cerebral ischemia is directly caused by cessation of blood flow. In transient middle cerebral artery occlusion (MCAO), prolonged T(1) relaxation was detected within 10 min, with a subsequent increase during the course of ischemia. Spin density did not change during the first hour, showing that T(1) increase was not caused by net accumulation of water. Interestingly, partial recovery of T(1) upon release of MCAO, occurring independent of long-term tissue outcome, was observed only in concert with diffusion recovery.
Collapse
Affiliation(s)
- M I Kettunen
- NMR Research Group, A. I. Virtanen Institute for Molecular Sciences, University of Kuopio, Kuopio, Finland
| | | | | | | | | | | |
Collapse
|
42
|
Nakai A, Asakura H, Taniuchi Y, Koshino T, Araki T, Siesjö BK. Effect of alpha-phenyl-N-tert-butyl nitrone (PBN) on fetal cerebral energy metabolism during intrauterine ischemia and reperfusion in rats. Pediatr Res 2000; 47:451-6. [PMID: 10759150 DOI: 10.1203/00006450-200004000-00007] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The objective of the present study was to explore whether a free radical spin trap agent, alpha-phenyl-N-tert-butyl nitrone (PBN), influences bioenergetic failure induced in the 20-day-old fetal brain by 30 min of intrauterine ischemia in Wistar rats. Fetal brains were frozen in situ at the end of ischemia and after 1, 2, and 4 h of recirculation for analysis of ATP, ADP, AMP, and lactate. PBN or vehicle was given 1 h after recirculation. Tissue oxygen tension was evaluated in placental and fetal cerebral tissues throughout the whole periods of 30 min of ischemia and 4 h of recirculation. Ischemia was associated with a decrease in ATP concentration and an increase in lactate concentration (p < 0.001). Recirculation (1 and 2 h) led to a recovery of ATP concentration, but continued reflow (4 h) was associated with a secondary deterioration of high-energy phosphates (p < 0.01). Lactate concentration increased during this recovery period. This deterioration was prevented by PBN (p < 0.05). After 30 min of ischemia, tissue oxygen tension in placenta and fetal brain decreased to about 30% and 50% of control, respectively. However, recirculation brought about a recovery of oxygen delivery. The results indicate that although during the early time period after ischemia fetal cerebral energy metabolism is maintained by an acceleration of the anaerobic glycolytic rate, secondary deterioration of cellular bioenergetic state develops in the immature fetal brain. This deterioration may be due to mitochondrial dysfunction, which may be induced by oxygen-derived free radicals, and not by compromised microcirculation.
Collapse
Affiliation(s)
- A Nakai
- Department of Obstetrics and Gynecology, Nippon Medical School, Tokyo, Japan
| | | | | | | | | | | |
Collapse
|
43
|
Cipolla MJ, Lessov N, Clark WM, Haley EC. Postischemic attenuation of cerebral artery reactivity is increased in the presence of tissue plasminogen activator. Stroke 2000; 31:940-5. [PMID: 10754003 DOI: 10.1161/01.str.31.4.940] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE We investigated the combined effect of tissue plasminogen activator and ischemia on middle cerebral artery (MCA) reactivity to determine whether abnormal MCA function after 2 hours of ischemia was worse in arteries perfused with recombinant tissue plasminogen activator (rtPA). METHODS The intraluminal suture model of focal cerebral ischemia was used to induce 2 hours of ischemia in rats, after which occluded MCAs were removed and studied in vitro with an arteriograph system that allowed control of transmural pressure (TMP) and measurement of lumen diameter. Arteries were either nonischemic (control; n=8), nonischemic and perfused with 400 microg/mL rtPA (rtPA; n=5), ischemic (ISC; n=6), or ischemic and perfused with 400 microg/mL rtPA (ISC-rtPA; n=6). After a 1-hour equilibration at 75 mm Hg, TMP was increased to 125 mm Hg and lumen diameter was recorded at each pressure. Reactivity to acetylcholine (ACh, 0.1 to 10.0 micromol/L) and serotonin (0.01 to 10 micromol/L) was then determined. RESULTS Control arteries responded myogenically to pressure and increased the amount of tone from 18.5+/-3.8% at 75 mm Hg to 24.8+/-3.0% at 125 mm Hg (P<0.05), which decreased diameter from 241+/-7 to 232+/-6 microm. In contrast, all other groups decreased tone at 125 mm Hg, which demonstrated a loss of myogenicity. The percent tone in each group at 75 versus 125 mm Hg was rtPA, 16.0+/-4.5% versus 11.8+/-3.8%; ISC, 23.5+/-4.5% versus 13. 5+/-3.1%; and ISC-rtPA, 23.5+/-4.2% versus 12.3+/-3.2% (P<0.05 for all). The percent increase in lumen diameter at each concentration of ACh was diminished in all groups compared with control; ISC-rtPA arteries responded the least, which suggests an additive effect of rtPA in ischemic arteries. The percent increase in lumen diameter at 10(-5)mol/L ACh was 23+/-4% for control versus 15+/-2% for rtPA; 17+/-3% for ISC arteries (P<0.05), and 8+/-2% for ISC-rtPA arteries (P<0.01). Sensitivity to serotonin was equally diminished in all groups compared with control: EC(50) (micromol/L) was 0.06+/-0.01 for control, 0.17+/-0.02 for rtPA, 0.22+/-0.07 for ISC, and 0.16+/-0. 04 for ISC-rtPA (P<0.05). CONCLUSIONS These results demonstrate that both ischemia and rtPA perfusion diminish cerebral artery reactivity and that the combination may produce an additive effect. This impaired reactivity may contribute to reperfusion-induced injury during or after thrombolysis by altering upstream cerebrovascular resistance.
Collapse
Affiliation(s)
- M J Cipolla
- Departments of Obstetrics/Gynecology, Pharmacology, and Neurology, University of Vermont College of Medicine, Burlington, VT, USA
| | | | | | | |
Collapse
|
44
|
Gidö G, Cronberg T, Wieloch T. The effect of alpha-phenyl-tert-butyl nitrone (PBN) on free radical formation in transient focal ischaemia measured by microdialysis and 3,4-dihydroxybenzoate formation. ACTA PHYSIOLOGICA SCANDINAVICA 2000; 168:277-85. [PMID: 10712565 DOI: 10.1046/j.1365-201x.2000.00657.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
alpha-phenyl-tert-butyl nitrone (PBN) reduces infarct size, improves recovery of brain energy metabolism and delays the secondary increase in extracellular potassium after focal ischaemia, presumably by trapping OH radicals. We investigated the effect of PBN on the formation of 3,4-dihydroxybenzoic acid (3,4-DHBA) as a measure of OH radical formation, during and following middle cerebral artery occlusion (MCAO). Rats, subjected to 2 h of ischaemia followed by 3 h of recirculation, were injected with either vehicle or PBN (100 mg kg-1 i.p.) prior to MCAO or immediately after recirculation, respectively. The in vivo microdialysis technique was used to collect samples for analysis of 3,4-DHBA by HPLC. The basal levels of 3,4-DHBA were 56-77 nmol L-1 in the four groups. During ischaemia, the formation of 3,4-DHBA decreased by about 50% in all groups. Upon recirculation, a 3-fold rise in 3,4-DHBA formation was seen. At 2 h of recirculation the mean value of 3,4-DHBA in the pretreated, vehicle-injected animals was 125 +/- 18 nmol L-1 and in the PBN-injected 145 +/- 48 nmol L-1, respectively. When the animals were treated after MCAO either with vehicle or PBN the values at 2 h recirculation were 155 +/- 148 and 189 +/- 145 nmol L-1, respectively. No statistically significant difference between vehicle- and PBN-injected groups was seen. We conclude that during reperfusion following MCAO, hydroxyl radical formation increases. The increase is not ameliorated by PBN which suggests that PBN does not protect the brain by a general scavenging of OH radicals, although tissue specific actions cannot be excluded.
Collapse
Affiliation(s)
- G Gidö
- Laboratory for Experimental Brain Research, Wallenberg Neuroscience Center, Lund University, Lund, Sweden
| | | | | |
Collapse
|
45
|
Mackensen GB, Nellgård B, Sarraf-Yazdi S, Dexter F, Steffen RP, Grocott HP, Warner DS. Post-ischemic RSR13 amplifies the effect of dizocilpine on outcome from transient focal cerebral ischemia in the rat. Brain Res 2000; 853:15-21. [PMID: 10627303 DOI: 10.1016/s0006-8993(99)02212-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In a recent study of focal cerebral ischemia in rats, pre-ischemic administration of the synthetic allosteric hemoglobin modifier RSR13 (2-[4-[[3,5-dimethylanilino) carbonyl] methyl] phenoxy]-2-methylproprionic acid) reduced cerebral infarct size when combined with the NMDA receptor antagonist dizocilpine (MK-801) but not when given alone. We hypothesized that post-ischemic RSR13 administration would enhance neuroprotection afforded by NMDA receptor antagonism in a rat model of transient middle cerebral artery occlusion (MCAO). Fasted normothermic Wistar rats underwent 75 min of temporary MCAO. At onset of reperfusion, rats randomly received: (1) 0.9% NaCl (vehicle) i.v. alone (n=16); (2) 0.9% NaCl+dizocilpine (0.25 mg/kg) i.v. (n=16); or (3) RSR13 (150 mg/kg)+dizocilpine (0.25 mg/kg) i.v. (n=17). Seven days later, neurologic deficit and cerebral infarct size were determined. Dizocilpine alone compared to vehicle reduced mean+/-S.D. subcortical (52+/-24 mm(3) vs. 122+/-64 mm(3), P=0.003) and cortical (35+/-35 mm(3) vs. 125+/-72 mm(3), P=0.00074) infarct volumes. When compared to dizocilpine alone, the combination of RSR13+dizocilpine further reduced subcortical (37+/-14 mm(3) vs. 52+/-24 mm(3), P=0. 034) and cortical (8+/-19 mm(3) vs. 35+/-35 mm(3), P=0.018) infarct size. RSR13+dizocilpine improved neurologic scores vs. either dizocilpine alone (P=0.0014) or vehicle (P=10(-7)). The combination of NMDA receptor antagonism and a RSR13 mediated rightward shift of the oxy-hemoglobin dissociation curve improved outcome from MCAO. Because this occurred after reperfusion, our results suggest that the post-ischemic brain continues to suffer from hypoperfusion defects, which are amenable to therapy by enhanced O(2) delivery. The results also support the concept that neuroprotective strategies, which combine drugs with different mechanisms of action, may yield cumulative benefits.
Collapse
Affiliation(s)
- G B Mackensen
- Department of Anesthesiology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
| | | | | | | | | | | | | |
Collapse
|
46
|
van Dorsten FA, Hata R, Maeda K, Franke C, Eis M, Hossmann KA, Hoehn M. Diffusion- and perfusion-weighted MR imaging of transient focal cerebral ischaemia in mice. NMR IN BIOMEDICINE 1999; 12:525-534. [PMID: 10668045 DOI: 10.1002/(sici)1099-1492(199912)12:8<525::aid-nbm597>3.0.co;2-f] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Temporary focal ischaemia was induced in wild-type C57Black/6 mice by thread occlusion of the middle cerebral artery (MCA). Recirculation was started after 60 min and maintained for 24 h, after which the mouse brain was frozen in situ. Development of the cerebral infarct was monitored by diffusion-, perfusion- and T(2)-weighted magnetic resonance imaging (MRI) during ischaemia, during the early reperfusion period of 90 min, and at 24 h after reperfusion. Ischaemia caused a marked reduction of the perfusion signal intensity and of the apparent diffusion coefficient (ADC) of tissue water in the ipsilateral MCA territory. In sham-operated control animals ADC remained unchanged. Hemispheric lesion volume after 1 h MCA occlusion was 53 +/- 6% (n = 6), as defined by an ADC decrease of more than 20%. Recirculation reduced hemispheric lesion volume to only 27 +/- 13%, while there was a trend towards secondary lesion growth at 24 h. Post-ischaemic recovery of perfusion was slow, heterogeneous and incomplete. A region-of-interest analysis showed only partial and transient recovery of the ADC, particularly in the dorsolateral cortex and lateral caudate putamen, which may be explained by inadequate reperfusion in these regions. Detailed MRI studies of cerebral ischaemia and reperfusion may now also be performed in the transgenic mice.
Collapse
Affiliation(s)
- F A van Dorsten
- Max-Planck-Institute for Neurological Research, Department of Experimental Neurology, Cologne, Germany
| | | | | | | | | | | | | |
Collapse
|
47
|
Zaharchuk G, Mandeville JB, Bogdanov AA, Weissleder R, Rosen BR, Marota JJ. Cerebrovascular dynamics of autoregulation and hypoperfusion. An MRI study of CBF and changes in total and microvascular cerebral blood volume during hemorrhagic hypotension. Stroke 1999; 30:2197-204; discussion 2204-5. [PMID: 10512929 DOI: 10.1161/01.str.30.10.2197] [Citation(s) in RCA: 114] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE To determine how cerebral blood flow (CBF), total and microvascular cerebral blood volume (CBV), and blood oxygenation level-dependent (BOLD) contrast change during autoregulation and hypotension using hemodynamic MRI. METHODS Using arterial spin labeling and steady-state susceptibility contrast, we measured CBF and changes in both total and microvascular CBV during hemorrhagic hypotension in the rat (n=9). RESULTS We observed CBF autoregulation for mean arterial blood pressure (MABP) between 50 and 140 mm Hg, at which average CBF was 1.27+/-0.44 mL. g(-1). min(-1) (mean+/-SD). During autoregulation, total and microvascular CBV changes were small and not significantly different from CBF changes. Consistent with this, no significant BOLD changes were observed. For MABP between 10 and 40 mm Hg, total CBV in the striatum increased slightly (+7+/-12%, P<0.05) whereas microvascular CBV decreased (-15+/-17%, P<0.01); on the cortical surface, total CBV increases were larger (+21+/-18%, P<0.01) and microvascular CBV was unchanged (3+/-22%, P>0.05). With severe hypotension, both total and microvascular CBV decreased significantly. Over the entire range of graded global hypoperfusion, there were increases in the CBV/CBF ratio. CONCLUSIONS Parenchymal CBV changes are smaller than those of previous reports but are consistent with the small arteriolar fraction of total blood volume. Such measurements allow a framework for understanding effective compensatory vasodilation during autoregulation and volume-flow relationships during hypoperfusion.
Collapse
Affiliation(s)
- G Zaharchuk
- Harvard-MIT Division of Health Sciences and Technology, Harvard Medical School, Boston, Massachusetts, USA.
| | | | | | | | | | | |
Collapse
|
48
|
Siesjö BK, Elmér E, Janelidze S, Keep M, Kristián T, Ouyang YB, Uchino H. Role and mechanisms of secondary mitochondrial failure. ACTA NEUROCHIRURGICA. SUPPLEMENT 1999; 73:7-13. [PMID: 10494335 DOI: 10.1007/978-3-7091-6391-7_2] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Ischemia is accompanied by mitochondrial dysfunction, as assessed by measurements of mitochondrial respiratory activities in vitro. Following brief periods of ischemia, mitochondrial function is usually normalized during reperfusion. However, particularly after ischemia of longer duration, reperfusion may be accompanied by secondary mitochondrial failure. After short periods of ischemia this is observed in selectively vulnerable areas and, after intermediate to long periods of ischemia, in other areas as well. However, it has remained unsettled if the mitochondrial dysfunction is the result or the cause of cell death. Although it has been commonly assumed that such failure is secondary to cell injury by other mechanisms, recent results suggest that mitochondrial dysfunction may be the cause of cell death. Indirect evidence for this postulate is provided by experiments showing that cyclosporin A (CsA), when allowed to cross the blood-brain barrier, is a potent neuroprotectant. CsA is a virtually specific blocker of the mitochondrial permeability transition (MPT) pore, a voltage-gated channel allowing molecules and ions with a mass < 1500 Daltons to pass the inner mitochondrial membrane. Experiments on isolated cells in vitro demonstrate that cell calcium accumulation or oxidative stress triggers the assembly of an MPT pore, which leads to collapse of the mitochondrial membrane potential, to ATP hydrolysis, to enhanced production of reactive oxygen species (ROS), and to cell death. The beneficial effect of CsA could thus be related to its ability to block the MPT pore. Longer periods of ischemia, such as occurs after transient middle cerebral artery (MCA) occlusion, lead to pan-necrotic lesions (infarction). In the rat, recirculation following 2 h of MCA occlusion leads to partial normalization of the bioenergetic state but this is followed within 4-6 h by secondary bioenergetic failure. The latter seems unrelated to blockade of the microcirculation, but correlates to secondary mitochondrial failure. The brain damage incurred is ameliorated by the spin trap alpha-phenyl-N-butyl nitrone (PBN) and by the immunosuppressant FK506 even when given 1-3 h after the start of recirculation. The two drugs also prevent the secondary mitochondrial failure during early recirculation, suggesting that such failure is pathogenetically important. Probably, though, the mitochondrial dysfunction involves not only the assembly of an MPT pore but also other mechanisms. Since recirculation is associated with release of mitochondrial proteins it is not unlikely that such proteins, e.g. cytochrome c, trigger cascades of events leading to cell death.6.
Collapse
Affiliation(s)
- B K Siesjö
- Center for the Study of Neurological Disease, Queen's Medical Center, Honolulu, USA
| | | | | | | | | | | | | |
Collapse
|
49
|
Kuroda S, Tsuchidate R, Smith ML, Maples KR, Siesjö BK. Neuroprotective effects of a novel nitrone, NXY-059, after transient focal cerebral ischemia in the rat. J Cereb Blood Flow Metab 1999; 19:778-87. [PMID: 10413033 DOI: 10.1097/00004647-199907000-00008] [Citation(s) in RCA: 182] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Recent results have demonstrated that the spin trapping agent alpha-phenyl-N-tert-butyl nitrone (PBN) reduces infarct volume in rats subjected to 2 hours of middle cerebral artery occlusion, even when given 1 to 3 hours after the start of recirculation. In the current study, the authors assessed the effect of NXY-059, a novel nitrone that is more soluble than PBN. Loading doses were given of 0.30, 3.0, or 30 mg x kg(-1) followed by 0.30, 3.0, or 30 mg x kg(-1) x h(-1) for 24 or 48 hours. Dose-response studies showed that when treatment was begun 1 hour after recirculation, 0.30 mg x kg(-1) had a small and 30 mg x kg(-1) a marked effect on infarct volume. At equimolar doses (3.0 mg x kg(-1) for NXY-059 and 1.4 mg x kg(-1) for PBN), NXY-059 was more efficacious than PBN. Similar results were obtained when a recovery period of 7 days was allowed. The window of therapeutic opportunity for NXY-059 was 3 to 6 hours after the start of recirculation. Studies of the transfer constant of [14C]NXY-059 showed that, in contrast to PBN, this more soluble nitrone penetrates the blood-brain barrier less extensively. This fact, and the pronounced antiischemic effect of NXY-059, suggest that the delayed events leading to infarction may be influenced by reactions occurring at the blood-endothelial interface.
Collapse
Affiliation(s)
- S Kuroda
- Laboratory for Experimental Brain Research, Wallenberg Neuroscience Center, Lund University, Sweden
| | | | | | | | | |
Collapse
|
50
|
Kastrup A, Engelhorn T, Beaulieu C, de Crespigny A, Moseley ME. Dynamics of cerebral injury, perfusion, and blood-brain barrier changes after temporary and permanent middle cerebral artery occlusion in the rat. J Neurol Sci 1999; 166:91-9. [PMID: 10475101 DOI: 10.1016/s0022-510x(99)00121-5] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
By means of magnetic resonance imaging (MRI) we longitudinally monitored the evolution of ischemic injury, changes in cerebral hemodynamics and alterations of the blood-brain barrier (BBB) during permanent or temporary middle cerebral artery occlusion (MCAO) in rats. Using the intraluminal suture occlusion model, male Sprague-Dawley rats were subjected to either permanent MCAO (Group A, n = 6), reperfusion after 1 h (Group B, n = 5), or reperfusion after 3 h (Group C, n = 5). Diffusion- and perfusion-weighted MRI and Gd-DTPA enhanced T1-weighted images were performed at six time points from 0.5 to 6 h post-MCAO. The lesion volume increased progressively in group A, decreased significantly in group B (P<0.01), and only showed a tendency toward reduction in group C. Perfusion-weighted MRI delineated severe perfusion deficits in the ischemic core, confirmed early and late reperfusion, and was able to demonstrate postischemic hyperperfusion in group C. Gd-DTPA extravasation was found in all animals with permanent MCAO and initially became grossly visible between 4.5 and 6 h post-MCAO. While only 2 animals demonstrated contrast enhancement in group B, widespread BBB changes were detected immediately following late reperfusion (Group C). Our results demonstrate that with advanced MRI techniques, alterations of the BBB can be correlated with the hemodynamic and biophysical consequences of reperfusion.
Collapse
Affiliation(s)
- A Kastrup
- Department of Radiology, Lucas MRS Center, Stanford University School of Medicine, CA 94305-5488, USA.
| | | | | | | | | |
Collapse
|