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Huang HT, Tung TH, Lin M, Wang X, Li X, Liang K, Qian Q, Chen PE. Characterizing spatiotemporal progression and prediction of infarct lesion volumes in experimental acute ischemia using quantitative perfusion and diffusion imaging. Appl Radiat Isot 2020; 168:109522. [PMID: 33290998 DOI: 10.1016/j.apradiso.2020.109522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 11/09/2020] [Accepted: 11/15/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE This study was conducted to explore the diagnostic value of arterial spin labeling (ASL) combined with diffusion weighted imaging (DWI) in characterizing the spatiotemporal progression of infarct lesions in a rabbit middle cerebral artery occlusion (MCAO) model and predicting the acute cerebral infarction (ACI) volume. MATERIALS AND METHODS Forty-two male rabbits (2.9 ± 0.2 kg body weight) were used in this experimental study. Animals were initially anesthetized by intravenous injection of uratan. There were seven experimental groups with six rabbits in each group. The apparent diffusion coefficient (ADC) and cerebral blood flow (CBF) thresholds were established in the control group (n = 6), which were sacrificed at 12 h, stained for infarct volume, and imaged at each time point. RESULTS The normal ADC and CBF were estimated as 0.90 ± 0.03 × 10-3 mm2/s and 0.68 ± 0.06 mL g-1 min-1, respectively. The viability thresholds of ADC and CBF yielding the lesion volumes (LVs) at 3 h, which best approximated the 2,3,5-triphenyltetrazolium chloride (TTC) infarct volumes at 12 h, were 0.52 ± 0.02 × 10-3 mm2/s (42.2 ± 3% reduction) and 0.33 ± 0.09 mL g-1 min-1 (51.0 ± 11% reduction), respectively. The temporal evolution of the ADC- and CBF-defined LVs showed a significant perfusion/diffusion mismatch up to 1 h (p = 0.001). CONCLUSION ADC values and ACI volumes were positively correlated, while CBF was negatively correlated, which is supposed to be a reference for predicting ACI volume.
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Affiliation(s)
- Hai-Tao Huang
- Department of MRI, Maoming People's Hospital, Guangdong Province, China.
| | - Tao-Hsin Tung
- Department of Medical Research and Education, Cheng Hsin General Hospital, Taipei, Taiwan, China.
| | - Min Lin
- Department of Radiology, The Third Affiliated Hospital of Zhejiang Chinese Medical University, Zhejiang Province, China.
| | - Xinmin Wang
- Department of MRI, Maoming People's Hospital, Guangdong Province, China.
| | - Xie Li
- Department of Computed Tomography, Maoming People's Hospital, Guangdong Province, China.
| | - Kaimin Liang
- Department of MRI, Maoming People's Hospital, Guangdong Province, China.
| | - Qi Qian
- Department of Radiology, The Third Affiliated Hospital of Zhejiang Chinese Medical University, Zhejiang Province, China.
| | - Pei-En Chen
- Institute of Health Policy and Management, National Taiwan University, Taipei, Taiwan, China; Taiwan association of health industry management and development, Taipei, Taiwan, China.
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Lu Y, Kang J, Bai Y, Zhang Y, Li H, Yang X, Xiang X, Wang X, Huang Y, Su J, Chen Y, Li B, Sun L. Hyperbaric oxygen enlarges the area of brain damage in MCAO rats by blocking autophagy via ERK1/2 activation. Eur J Pharmacol 2014; 728:93-9. [PMID: 24512724 DOI: 10.1016/j.ejphar.2014.01.066] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 01/15/2014] [Accepted: 01/26/2014] [Indexed: 12/29/2022]
Abstract
Hyperbaric oxygen (HBO) is emerging as a therapy for brain ischemia, although its benefits are still debated. The present study aimed to investigate the effect of HBO on brain damage in a rat model of transient focal cerebral ischemia and its underlying mechanism of action. Male Wistar rats, which had suffered 1.5h of transient middle cerebral artery occlusion (tMCAO) and had a Longa's neuron score of 3, were given pure oxygen at 3.0 atm absolute, for 60 min after the third hour of reperfusion. After 24h of reperfusion, rat brains were removed and studied. 2,3,5-triphenyltetrazolium chloride (TTC) and hematoxylin and eosin staining revealed that the infarct ratio in the HBO group increased remarkably when compared with the MCAO group. Up-regulation of extracellular signal-regulated kinase 1/2 (ERK1/2) activation was detected in the HBO group because of reactive oxygen species (ROS) generation. Autophagy appeared to be obstructed in the HBO group. Administration of the ERK1/2 inhibitor U0126 decreased the infarct ratio and improved protein clearance by autophagy in the HBO group. Collectively, these results suggest that HBO enlarges the area of brain damage via reactive oxygen species-induced activation of ERK1/2, which interrupts autophagy flux.
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Affiliation(s)
- Yuxiong Lu
- Department of Pathophysiology, Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, 126 Xinmin Street, Changchun, Jilin 130021, China
| | - Jinsong Kang
- Department of Pathophysiology, Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, 126 Xinmin Street, Changchun, Jilin 130021, China
| | - Yang Bai
- School of Public Health, Jilin University, Changchun, China
| | - Yu Zhang
- Department of Pathophysiology, Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, 126 Xinmin Street, Changchun, Jilin 130021, China
| | - Hongyan Li
- Department of Pathophysiology, Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, 126 Xinmin Street, Changchun, Jilin 130021, China
| | - Xiaochun Yang
- Department of Pathophysiology, Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, 126 Xinmin Street, Changchun, Jilin 130021, China
| | - Xiyan Xiang
- Department of Pathophysiology, Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, 126 Xinmin Street, Changchun, Jilin 130021, China
| | - Xinxue Wang
- Department of Pathophysiology, Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, 126 Xinmin Street, Changchun, Jilin 130021, China
| | | | - Jing Su
- Department of Pathophysiology, Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, 126 Xinmin Street, Changchun, Jilin 130021, China
| | - Ye Chen
- Department of Pathophysiology, Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, 126 Xinmin Street, Changchun, Jilin 130021, China
| | - Bingjin Li
- Department of Pathophysiology, Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, 126 Xinmin Street, Changchun, Jilin 130021, China.
| | - Liankun Sun
- Department of Pathophysiology, Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, 126 Xinmin Street, Changchun, Jilin 130021, China.
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Wang W, Kang J, Li H, Su J, Wu J, Xu Y, Yu H, Xiang X, Yi H, Lu Y, Sun L. Regulation of endoplasmic reticulum stress in rat cortex by p62/ZIP through the Keap1-Nrf2-ARE signalling pathway after transient focal cerebral ischaemia. Brain Inj 2013; 27:924-33. [PMID: 23782269 DOI: 10.3109/02699052.2013.793397] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
PRIMARY OBJECTIVE p62/ZIP as the autophagy receptor can transport the misfolded proteins to a macroautophagy-lysosome system for degradation and also create a positive feedback loop between p62/ZIP and Nrf2. However, the role of p62/ZIP on cerebral ischaemia is unclear. The aim of this study was to evaluate the role of p62/ZIP in the regulation of endoplasmic reticulum(ER) stress induced by cerebral ischaemia/reperfusion. RESEARCH DESIGN Different ischemic periods were designed by transient middle cerebral artery occlusion (tMCAO) using the suture method. METHODS AND PROCEDURES At 24 hours after reperfusion, the ischaemic brain tissue was studied histologically and biochemically for autophagic, ER stress and Keap1-Nrf2-ARE signalling pathway markers. MAIN OUTCOMES AND RESULTS Prolongation of ischaemia significantly increased the cortical injury observed in rats and was associated with a gradual increase in the protein expression of ubiquitin-aggregates, Grp78, GADD153/CHOP and p62/ZIP. Autophagy marker Atg12-Atg5 and LC3-PE increased and then decreased. Moreover, p62/ZIP mRNA expression increased and then decreased and was consistent with Nrf2 activation. CONCLUSIONS p62/ZIP not only plays a key role in scavenging protein aggregates during autophagy, but it may also be involved in preventing oxidative injury and alleviating ER stress through the Keap1-Nrf2-ARE signalling pathway during cerebral ischaemia/reperfusion injury.
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Affiliation(s)
- Weiwei Wang
- Department of Pathophysiology, Norman Bethune College of Medicine, Jilin University, 126 Xinmin Street, Changchun, Jilin, China
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Luoma JI, Stern CM, Mermelstein PG. Progesterone inhibition of neuronal calcium signaling underlies aspects of progesterone-mediated neuroprotection. J Steroid Biochem Mol Biol 2012; 131:30-6. [PMID: 22101209 PMCID: PMC3303940 DOI: 10.1016/j.jsbmb.2011.11.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Revised: 10/31/2011] [Accepted: 11/02/2011] [Indexed: 01/02/2023]
Abstract
Progesterone is being utilized as a therapeutic means to ameliorate neuron loss and cognitive dysfunction following traumatic brain injury. Although there have been numerous attempts to determine the means by which progesterone exerts neuroprotective effects, studies describing the underlying molecular mechanisms are lacking. What has become clear, however, is the notion that progesterone can thwart several physiological processes that are detrimental to neuron function and survival, including inflammation, edema, demyelination and excitotoxicity. One clue regarding the means by which progesterone has restorative value comes from the notion that these aforementioned biological processes all share the common theme of eliciting pronounced increases in intracellular calcium. Thus, we propose the hypothesis that progesterone regulation of calcium signaling underlies its ability to mitigate these cellular insults, ultimately leading to neuroprotection. Further, we describe recent findings that indicate neuroprotection is achieved via progesterone block of voltage-gated calcium channels, although additional outcomes may arise from blockade of various other ion channels and neurotransmitter receptors. This article is part of a Special Issue entitled 'Neurosteroids'.
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Affiliation(s)
- Jessie I Luoma
- Graduate Program in Neuroscience and Department of Neuroscience, University of Minnesota, 321 Church Street SE, Minneapolis, MN 55455, USA
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Wang J, Jiang C, Liu C, Li X, Chen N, Hao Y. Neuroprotective effects of progesterone following stroke in aged rats. Behav Brain Res 2010; 209:119-22. [DOI: 10.1016/j.bbr.2010.01.026] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2009] [Revised: 01/16/2010] [Accepted: 01/20/2010] [Indexed: 10/19/2022]
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Harper MT, Poole AW. Protein kinase Ctheta negatively regulates store-independent Ca2+ entry and phosphatidylserine exposure downstream of glycoprotein VI in platelets. J Biol Chem 2010; 285:19865-73. [PMID: 20388711 PMCID: PMC2888397 DOI: 10.1074/jbc.m109.085654] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Platelet activation must be tightly controlled to provide an effective, but not excessive, response to vascular injury. Cytosolic calcium is a critical regulator of platelet function, including granule secretion, integrin activation, and phosphatidylserine (PS) exposure. Here we report that the novel protein kinase C isoform, PKCtheta, plays an important role in negatively regulating Ca(2+) signaling downstream of the major collagen receptor, glycoprotein VI (GPVI). This limits PS exposure and so may prevent excessive platelet procoagulant activity. Stimulation of GPVI resulted in significantly higher and more sustained Ca(2+) signals in PKCtheta(-/-) platelets. PKCtheta acts at multiple distinct sites. PKCtheta limits secretion, reducing autocrine ADP signaling that enhances Ca(2+) release from intracellular Ca(2+) stores. PKCtheta thereby indirectly regulates activation of store-operated Ca(2+) entry. However, PKCtheta also directly and negatively regulates store-independent Ca(2+) entry. This pathway, activated by the diacylglycerol analogue, 1-oleoyl-2-acetyl-sn-glycerol, was enhanced in PKCtheta(-/-) platelets, independently of ADP secretion. Moreover, LOE-908, which blocks 1-oleoyl-2-acetyl-sn-glycerol-induced Ca(2+) entry but not store-operated Ca(2+) entry, blocked the enhanced GPVI-dependent Ca(2+) signaling and PS exposure seen in PKCtheta(-/-) platelets. We propose that PKCtheta normally acts to restrict store-independent Ca(2+) entry during GPVI signaling, which results in reduced PS exposure, limiting platelet procoagulant activity during thrombus formation.
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Affiliation(s)
- Matthew T Harper
- Department of Physiology and Pharmacology, School of Medical Sciences, University of Bristol, BS8 1TD Bristol, United Kingdom
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Durukan A, Tatlisumak T. Preconditioning-induced ischemic tolerance: a window into endogenous gearing for cerebroprotection. EXPERIMENTAL & TRANSLATIONAL STROKE MEDICINE 2010; 2:2. [PMID: 20298534 PMCID: PMC2830184 DOI: 10.1186/2040-7378-2-2] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2009] [Accepted: 01/21/2010] [Indexed: 12/31/2022]
Abstract
Ischemic tolerance defines transient resistance to lethal ischemia gained by a prior sublethal noxious stimulus (i.e., preconditioning). This adaptive response is thought to be an evolutionarily conserved defense mechanism, observed in a wide variety of species. Preconditioning confers ischemic tolerance if not in all, in most organ systems, including the heart, kidney, liver, and small intestine. Since the first landmark experimental demonstration of ischemic tolerance in the gerbil brain in early 1990's, basic scientific knowledge on the mechanisms of cerebral ischemic tolerance increased substantially. Various noxious stimuli can precondition the brain, presumably through a common mechanism, genomic reprogramming. Ischemic tolerance occurs in two temporally distinct windows. Early tolerance can be achieved within minutes, but wanes also rapidly, within hours. Delayed tolerance develops in hours and lasts for days. The main mechanism involved in early tolerance is adaptation of membrane receptors, whereas gene activation with subsequent de novo protein synthesis dominates delayed tolerance. Ischemic preconditioning is associated with robust cerebroprotection in animals. In humans, transient ischemic attacks may be the clinical correlate of preconditioning leading to ischemic tolerance. Mimicking the mechanisms of this unique endogenous protection process is therefore a potential strategy for stroke prevention. Perhaps new remedies for stroke are very close, right in our cells.
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Affiliation(s)
- Aysan Durukan
- Department of Neurology, Helsinki University Central Hospital, Helsinki, Finland.
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Simard JM, Tarasov KV, Gerzanich V. Non-selective cation channels, transient receptor potential channels and ischemic stroke. Biochim Biophys Acta Mol Basis Dis 2007; 1772:947-57. [PMID: 17446049 PMCID: PMC1986778 DOI: 10.1016/j.bbadis.2007.03.004] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2006] [Revised: 03/13/2007] [Accepted: 03/13/2007] [Indexed: 02/02/2023]
Abstract
Several pathways to neural cell death are involved in ischemic stroke, and all require monovalent or divalent cation influx, implicating non-selective cation (NC) channels. NC channels are also likely to be involved in the dysfunction of vascular endothelial cells that leads to formation of edema following cerebral ischemia. Two newly described NC channels have emerged as potential participants in ischemic stroke, the acid sensing ion channel (ASIC), and the sulfonylurea receptor-1 (SUR1)-regulated NC(Ca-ATP) channel. Non-specific blockers of NC channels, including pinokalant (LOE 908 MS) and rimonabant (SR141716A), have beneficial effects in rodent models of ischemic stroke. Evidence is accumulating that NC channels formed by members of the transient receptor potential (TRP) family are also up-regulated in ischemic stroke and may play a direct role in calcium-mediated neuronal death. The nascent field of NC channels, including TRP channels, in ischemic stroke is poised to provide novel mechanistic insights and therapeutic strategies for this often devastating human condition.
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Affiliation(s)
- J Marc Simard
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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Christensen T, Wienrich M, Ensinger HA, Diemer NH. The broad-spectrum cation channel blocker pinokalant (LOE 908 MS) reduces brain infarct volume in rats: a temperature-controlled histological study. Basic Clin Pharmacol Toxicol 2005; 96:316-24. [PMID: 15755315 DOI: 10.1111/j.1742-7843.2005.pto960407.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Activation of cation channels conducting Ca2+, Na+ and K+ is involved in the pathogenesis of infarction in experimental focal cerebral ischaemia. Pinokalant (LOE 908 MS) is a novel broad-spectrum inhibitor of several subtypes of such channels and has previously been shown to improve the metabolic and electrophysiologic status of the ischemic penumbra and to reduce lesion size on magnetic resonance images in the acute phase following middle cerebral artery occlusion in rats. The purpose of the present study was to investigate whether these beneficial effects of pinokalant are translated into permanent neuroprotection in terms of a reduction in infarct size one week after middle cerebral artery occlusion in rats. Halothane-anaesthetized male Wistar rats subjected to permanent distal middle cerebral artery occlusion were randomly assigned to one of two treatment groups: 1) Control (vehicle intravenous loading dose followed by infusion); 2) Pinokalant (0.5 mg/kg intravenous loading dose followed by infusion of 1.25 mg/kg/hr). Infusions started 30 min. after middle cerebral artery occlusion and were continued for 24 hr. Body temperature and mean arterial blood pressure were monitored by telemetry during this period and the spontaneous temperature after course in control rats established in other experiments was imitated. Seven days later histological brain sections were prepared and the infarct volumes measured. Body temperature did not differ between the groups. Mean arterial blood pressure was slightly higher in the pinokalant group. Pinokalant treatment significantly reduced cortical infarct volume from 33.8+/-15.8 mm3 to 24.5+/-13.1 mm3 (control group versus pinokalant group, P=0.017, t-test). Taking the effective drug plasma concentration established in other experiments into account revealed that in rats with plasma concentrations within the therapeutic interval, infarct volumes were further reduced to 17.9+/-7.5 mm3 (P<0.005).
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Affiliation(s)
- Thomas Christensen
- Laboratory of Molecular Neuropathology, Institute of Molecular Pathology, University of Copenhagen, Denmark.
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Beech DJ, Muraki K, Flemming R. Non-selective cationic channels of smooth muscle and the mammalian homologues of Drosophila TRP. J Physiol 2004; 559:685-706. [PMID: 15272031 PMCID: PMC1665181 DOI: 10.1113/jphysiol.2004.068734] [Citation(s) in RCA: 201] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2004] [Accepted: 07/20/2004] [Indexed: 12/25/2022] Open
Abstract
Throughout the body there are smooth muscle cells controlling a myriad of tubes and reservoirs. The cells show enormous diversity and complexity compounded by a plasticity that is critical in physiology and disease. Over the past quarter of a century we have seen that smooth muscle cells contain--as part of a gamut of ion-handling mechanisms--a family of cationic channels with significant permeability to calcium, potassium and sodium. Several of these channels are sensors of calcium store depletion, G-protein-coupled receptor activation, membrane stretch, intracellular Ca2+, pH, phospholipid signals and other factors. Progress in understanding the channels has, however, been hampered by a paucity of specific pharmacological agents and difficulty in identifying the underlying genes. In this review we summarize current knowledge of these smooth muscle cationic channels and evaluate the hypothesis that the underlying genes are homologues of Drosophila TRP (transient receptor potential). Direct evidence exists for roles of TRPC1, TRPC4/5, TRPC6, TRPV2, TRPP1 and TRPP2, and more are likely to be added soon. Some of these TRP proteins respond to a multiplicity of activation signals--promiscuity of gating that could enable a variety of context-dependent functions. We would seem to be witnessing the first phase of the molecular delineation of these cationic channels, something that should prove a leap forward for strategies aimed at developing new selective pharmacological agents and understanding the activation mechanisms and functions of these channels in physiological systems.
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Affiliation(s)
- D J Beech
- School of Biomedical Sciences, University of Leeds, LS2 9JT, UK.
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Meng X, Fisher M, Shen Q, Sotak CH, Duong TQ. Characterizing the diffusion/perfusion mismatch in experimental focal cerebral ischemia. Ann Neurol 2004; 55:207-12. [PMID: 14755724 PMCID: PMC2949945 DOI: 10.1002/ana.10803] [Citation(s) in RCA: 120] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) can rapidly detect lesions in acute ischemic stroke patients. The PWI volume is typically substantially larger than the DWI volume shortly after onset, that is, a diffusion/ perfusion mismatch. The aims of this study were to follow the evolution of the diffusion/ perfusion mismatch in permanent and 60- minute temporary focal experimental ischemia models in Sprague-Dawley rats using the intraluminal middle cerebral artery occlusion (MCAO) method. DWI and arterial spin-labeled PWI were performed at 30, 60, 90, 120, and 180 minutes after occlusion and lesion volumes (mm(3)) calculated At 24 hours after MCAO, and infarct volume was determined using triphenyltetrazolium chloride staining. In the permanent MCAO group, the lesion volume on the ADC maps was significantly smaller than that on the cerebral blood flow maps through the first 60 minutes after MCAO; but not after 90 minutes of occlusion. With 60 minutes of transient ischemia, the diffusion/perfusion mismatch was similar, but after reperfusion, the lesion volumes on ADC and cerebral blood flow maps became much smaller. There was a significant difference in 24- hour infarct volumes between the permanent and temporary occlusion groups.
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Affiliation(s)
- Xiangjun Meng
- Department of Neurology, University of Massachusetts Medical School, Worcester, 01605, USA
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Kawanabe Y, Masaki T, Hashimoto N. Effects of the Ca++-permeable nonselective cation channel blocker LOE 908 on subarachnoid hemorrhage-induced vasospasm in the basilar artery in rabbits. J Neurosurg 2003; 98:561-4. [PMID: 12650428 DOI: 10.3171/jns.2003.98.3.0561] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT The Ca++ influx into vascular smooth-muscle cells (VSMCs) plays a fundamental role in the development and chronic effects of vasospasm after subarachnoid hemorrhage (SAH). The Ca++-permeable nonselective cation channels (NSCCs) are activated by several endothelium-derived constricting factors such as endothelin 1 (ET-1) and thromboxane A2. Moreover, the receptor-operated Ca++ channel blocker LOE 908 inhibits ET-1-induced extracellular Ca++ influx via NSCCs in the VSMCs of the basilar artery (BA) and the NSCC-dependent part of ET-1-induced vasoconstriction of BA rings. The purpose of the present study was to evaluate the in vivo role of LOE 908 on SAH-induced vasospasm. METHODS Forty-two Japanese white rabbits were assigned to seven groups. Treatment groups consisted of the following: 1) control rabbits without SAH that received a cisternal injection of saline; 2) rabbits with SAH that were subjected to the intravenous administration of saline; 3 through 6) rabbits with SAH that underwent the intravenous administration of 0.01. 0.1, 1, or 10 mg/kg LOE 908, respectively; and 7) rabbits without SAH that underwent the intravenous administration of 10 mg/kg LOE 908. Autologous blood was injected into the cisterna magna. The caliber of the BA was measured on angiographic studies before and after the cisternal injection of autologous blood. The intravenous injection of LOE 908 inhibited the magnitude of an SAH-induced vasosapsm. In addition, the concentration of LOE 908 required to relax vasospasm (1 mg/kg) correlated with that required to block Ca++ influx into VSMCs. CONCLUSIONS The Ca++ channel blocker LOE 908 may inhibit the magnitude of an SAH-induced vasospasm by blocking the influx of Ca++ through NSCCs in rabbit BAs. Blocking the NSCCs may represent a new treatment for cerebral vasospasm after SAH.
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Affiliation(s)
- Yoshifumi Kawanabe
- Department of Neurosurgery and Pharmacology, Kyoto University Graduate School of Medicine, Kyoto, Japan.
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