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Awad H, Efanov A, Rajan J, Denney A, Gigax B, Kobalka P, Kelani H, Basso DM, Bozinovski J, Tili E. Histological Findings After Aortic Cross-Clamping in Preclinical Animal Models. J Neuropathol Exp Neurol 2021; 80:895-911. [PMID: 34534333 PMCID: PMC8783616 DOI: 10.1093/jnen/nlab084] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Spinal cord ischemic injury and paralysis are devastating complications after open surgical repair of thoracoabdominal aortic aneurysms. Preclinical models have been developed to simulate the clinical paradigm to better understand the neuropathophysiology and develop therapeutic treatment. Neuropathological findings in the preclinical models have not been comprehensively examined before. This systematic review studies the past 40 years of the histological findings after open surgical repair in preclinical models. Our main finding is that damage is predominantly in the grey matter of the spinal cord, although white matter damage in the spinal cord is also reported. Future research needs to examine the neuropathological findings in preclinical models after endovascular repair, a newer type of surgical repair used to treat aortic aneurysms.
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Affiliation(s)
- Hamdy Awad
- From the Department of Anesthesiology, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA
| | - Alexander Efanov
- From the Department of Anesthesiology, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA
| | - Jayanth Rajan
- From the Department of Anesthesiology, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA
| | - Andrew Denney
- From the Department of Anesthesiology, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA
| | - Bradley Gigax
- From the Department of Anesthesiology, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA
| | - Peter Kobalka
- Department of Pathology, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA
| | - Hesham Kelani
- From the Department of Anesthesiology, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA
| | - D Michele Basso
- Department of Neuroscience, School of Health and Rehabilitation Sciences, The Ohio State University, Columbus, Ohio, USA
| | - John Bozinovski
- Division of Cardiac Surgery, Department of Surgery, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA
| | - Esmerina Tili
- From the Department of Anesthesiology, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA
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2
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Chen W, Zhao Z, Zhao S, Zhang L, Song Q. Resveratrol and Puerarin loaded polymeric nanoparticles to enhance the chemotherapeutic efficacy in spinal cord injury. Biomed Microdevices 2020; 22:69. [PMID: 32959235 DOI: 10.1007/s10544-020-00521-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/08/2020] [Indexed: 02/07/2023]
Abstract
Spinal cord injury includes inflammation and apoptosis of neurons, which is difficult to cure by systemic drug administration. Administration of natural active compounds (resveratrol and also Puerarin) by advance drug delivery technology improves the patient's conditions. Oil-in-water emulsion method was utilized to prepare resveratrol as well as puerarin loaded PLGA nanoparticles. The nanoparticles were subjected to mean zeta potential, mean particle size, encapsulation efficiency as well as in vitro drug release studies. The biochemical parameters i.e. malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD), advanced oxidation products (AOPP), catalase (CAT) and nitrite/nitrate levels were tested for the loaded nanoparticles. Reperfusion injury induced rats treated with 10 mg/kg resveratrol and puerarin loaded nanoparticles protects spine from ischemia injury and supports biological parameters. The mean particle size varies from 238 nm to 274 nm and also particle size distribution was mono-dispersed (0.239 to 0.318). Zeta potential value of nanoparticles was observed to be -12.6 ± 2.1 mV. Optimized nanoparticles reveals 72% -79% of drug release over 36 h by diffusion mechanism. Significantly, lowers the levels of plasma nitrite/nitrate level as well as phosphorylation of p38MAPK pathways in reperfusion injury induced rats. The resveratrol and puerarin loaded nanoparticles decreases free radicals produced by reperfusion injury induced rats, as well as decrease of oxidative stress because of IRI. Resveratrol and puerarin loaded nanoparticles decreases GSH, SOD and CAT antioxidant level, which helps in overall health improvement of patients.
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Affiliation(s)
- Wei Chen
- Department of Neurosurgery, Linyi central hospital, Yishui county, Linyi, 276400, Shandong province, China
| | - Zongqin Zhao
- Department of pathology, Qingdao Hiser Hospital, Qingdao, 266033, Shandong, China
| | - Shuchao Zhao
- Department of Pathology, Affiliated Hospital of Qingdao University, Qingdao, 266000, Shandong Province, China
| | - Lizhong Zhang
- Department of pathology, Linyi People's Hospital, Linyi, 276003, Shandong Province, China
| | - Qimin Song
- Department of Neurosurgery, Linyi People's Hospital, Linyi, 276003, Shandong province, China.
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Click-crosslinked injectable hyaluronic acid hydrogel is safe and biocompatible in the intrathecal space for ultimate use in regenerative strategies of the injured spinal cord. Methods 2015; 84:60-9. [PMID: 25846399 DOI: 10.1016/j.ymeth.2015.03.023] [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: 11/14/2014] [Accepted: 03/26/2015] [Indexed: 12/18/2022] Open
Abstract
Traumatic spinal cord injury (SCI) causes damage and degeneration at and around the lesion site resulting in a loss of function. SCI presents a complex regenerative problem due to the multiple aspects of growth inhibition and the heterogeneity in size, shape and extent of injury. Currently, there is no widely accepted treatment strategy available and delivering biomolecules to the central nervous system remains a challenge. With a view towards achieving local release, we designed a hydrogel that can be injected into the intrathecal space. Here we describe the synthesis and characterization of a click-crosslinked hyaluronic acid hydrogel and demonstrate controlled in vitro release of bioactive brain derived neurotrophic factor. Importantly, we demonstrate that this new hydrogel is both biocompatible in the intrathecal space based on immunohistochemistry of the host tissue response and safe based on behavioral analysis of locomotor function.
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Hayakawa K, Uchida S, Ogata T, Tanaka S, Kataoka K, Itaka K. Intrathecal injection of a therapeutic gene-containing polyplex to treat spinal cord injury. J Control Release 2014; 197:1-9. [PMID: 25449800 DOI: 10.1016/j.jconrel.2014.10.027] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 09/20/2014] [Accepted: 10/27/2014] [Indexed: 12/20/2022]
Abstract
Spinal cord injury (SCI) is a serious clinical problem that suddenly deprives patients of neurologic function and drastically diminishes their quality of life. Gene introduction has the potential to be effective for various pathological states of SCI because various proteins can be produced just by modifying nucleic acid sequences. In addition, the sustainable protein expression allows to maintain its concentration at an effective level at the target site in the spinal cord. Here we propose an approach using a polyplex system composed of plasmid DNA (pDNA) and a cationic polymer, poly{N'-[N-(2-aminoethyl)-2-aminoethyl]aspartamide} [PAsp(DET)], that has high capacity to promote endosome escape and the long-term safety by self-catalytically degrading within a few days. We applied brain-derived neurotrophic factor (BDNF)-expressing pDNA for SCI treatment by intrathecal injection of PAsp(DET)/pDNA polyplex. A single administration of polyplex for experimental SCI provided sufficient therapeutic effects including prevention of neural cell death and enhancement of motor function recovery. This lasted for a few weeks after SCI, demonstrating the capability of this system to express BDNF in a safe and responsible manner for treatment of various pathological states in SCI.
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Affiliation(s)
- Kentaro Hayakawa
- Department of Rehabilitation for the Movement Functions, Research Institute, National Rehabilitation Center for the Persons with Disabilities, Saitama, Japan; Sensory and Motor System Medicine, Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Satoshi Uchida
- Laboratory of Clinical Biotechnology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Toru Ogata
- Department of Rehabilitation for the Movement Functions, Research Institute, National Rehabilitation Center for the Persons with Disabilities, Saitama, Japan
| | - Sakae Tanaka
- Sensory and Motor System Medicine, Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Kazunori Kataoka
- Laboratory of Clinical Biotechnology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; Department of Materials Engineering, Graduate School of Engineering, The University of Tokyo, Tokyo, Japan.
| | - Keiji Itaka
- Sensory and Motor System Medicine, Faculty of Medicine, The University of Tokyo, Tokyo, Japan; Laboratory of Clinical Biotechnology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
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Yang HH, Hou CC, Lin MT, Chang CP. Attenuating Heat-Induced Acute Lung Inflammation and Injury by Dextromethorphan in Rats. Am J Respir Cell Mol Biol 2012; 46:407-13. [DOI: 10.1165/rcmb.2011-0226oc] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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An injectable drug delivery platform for sustained combination therapy. J Control Release 2009; 138:205-13. [PMID: 19442692 DOI: 10.1016/j.jconrel.2009.05.009] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2009] [Accepted: 05/06/2009] [Indexed: 11/22/2022]
Abstract
We report the development of a series of physical hydrogel blends composed of hyaluronan (HA) and methyl cellulose (MC) designed for independent delivery of one or more drugs, from 1 to 28 days, for ultimate application in spinal cord injury repair strategies. To achieve a diversity of release profiles we exploit the combination of fast diffusion-controlled release of dissolved solutes from the HAMC itself and slow drug release from poly(lactide-co-glycolide) particles dispersed within the gel. Delivery from the composite hydrogels was demonstrated using the neuroprotective molecules NBQX and FGF-2, which were released for 1 and 4 days, respectively; the neuroregenerative molecules dbcAMP and EGF, and proteins alpha-chymotrypsin and IgG, which were released for 28 days. alpha-chymotrypsin and IgG were selected as model proteins for the clinically relevant neurotrophin-3 and anti-NogoA. Particle loaded hydrogels were significantly more stable than HAMC alone and drug release was longer and more linear than from particles alone. The composite hydrogels are minimally swelling and injectable through a 30 gauge/200 microm inner diameter needle at particle loads up to 15 wt.% and particle diameters up to 15 microm.
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Kang CE, Poon PC, Tator CH, Shoichet MS. A New Paradigm for Local and Sustained Release of Therapeutic Molecules to the Injured Spinal Cord for Neuroprotection and Tissue Repair. Tissue Eng Part A 2009; 15:595-604. [DOI: 10.1089/ten.tea.2007.0349] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
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8
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Akuzawa S, Kazui T, Shi E, Yamashita K, Bashar AHM, Terada H. Interleukin-1 receptor antagonist attenuates the severity of spinal cord ischemic injury in rabbits. J Vasc Surg 2008; 48:694-700. [DOI: 10.1016/j.jvs.2008.04.011] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2008] [Revised: 03/23/2008] [Accepted: 04/06/2008] [Indexed: 10/21/2022]
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Chen YW, Chen YC, Lin CN, Chu CC, Lin MT, Wang JJ, Kao CH. The spinal anaesthetic effect of dextromethorphan, dextrorphan, and 3-methoxymorphinan. Eur J Pharmacol 2007; 569:188-93. [PMID: 17601557 DOI: 10.1016/j.ejphar.2007.05.019] [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: 12/28/2006] [Revised: 04/09/2007] [Accepted: 05/15/2007] [Indexed: 10/23/2022]
Abstract
Dextromethorphan, an antitussive, has a complex pharmacologic profile and has not been well studied. Our aim was to evaluate whether dextromethorphan and its metabolites, dextrorphan and 3-methoxymorphinan, have a spinal anaesthetic effect. Using a method of spinal blockade in rats, we evaluated the potencies and durations of the effects of dextromethorphan and its metabolites on spinal blockades of motor function and nociception. Bupivacaine was the active control. We found that dextromethorphan and its metabolites produced a dose-related spinal blockade of motor function and nociception. On an ED(50) basis, the ranks of potencies were bupivacaine>dextrorphan>3-methoxymorphinan>dextromethorphan (p<0.05 for the differences). On an equipotent basis, dextrorphan and bupivacaine produced similarly longer nociceptive blockades than did dextromethorphan and 3-methoxymorphinan (p<0.05 for the differences). Co-administration of dextromethorphan or its metabolites with bupivacaine produced an additive effect. In conclusion, intrathecal injections of dextromethorphan or its metabolites, dextrorphan and 3-methoxymorphinan, produced dose-related spinal blockades of motor function and nociception. The suitability of these drugs as clinical spinal anaesthetics is worth further evaluation.
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Affiliation(s)
- Yu-Wen Chen
- Department of Medical Research, Chi-Mei Medical Centre, Tainan, Taiwan
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10
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Chen YW, Chu KS, Lin CN, Tzeng JI, Chu CC, Lin MT, Wang JJ. Dextromethorphan or dextrorphan have a local anesthetic effect on infiltrative cutaneous analgesia in rats. Anesth Analg 2007; 104:1251-5, tables of contents. [PMID: 17456682 DOI: 10.1213/01.ane.0000260330.18745.a8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Dextromethorphan blocks sodium channels, the site of action of local anesthetics. In this study we evaluated whether dextromethorphan has a local anesthetic effect. METHODS We administered dextromethorphan and its active metabolite--dextrorphan, and lidocaine subcutaneously to rats and tested them for cutaneous anesthesia. Drug-drug interactions and systemic safety indices (LD50s/ED50s) were also evaluated. RESULTS Dextromethorphan and dextrorphan had a local anesthetic effect after cutaneous infiltration. The ranking of potencies was dextromethorphan > dextrorphan > lidocaine (P < 0.01 for each comparison). A combination of dextromethorphan or dextrorphan with lidocaine produced an additive effect. Dextromethorphan and dextrorphan had 2.4- and 1.9-fold higher system safety indices than did lidocaine. CONCLUSION Dextromethorphan and dextrorphan were more potent local anesthetics than lidocaine, but with higher systemic safety indices. Coadministration of dextromethorphan or dextrorphan with lidocaine produced an additive effect.
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Affiliation(s)
- Yu-Wen Chen
- Department of Medical Research, Chi-Mei Medical Center, Tainan, Taiwan
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Shoichet MS, Tator CH, Poon P, Kang C, Baumann MD. Intrathecal drug delivery strategy is safe and efficacious for localized delivery to the spinal cord. PROGRESS IN BRAIN RESEARCH 2007; 161:385-92. [PMID: 17618992 DOI: 10.1016/s0079-6123(06)61027-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Neuroprotective and neuroregenerative strategies for spinal cord injury repair are limited in part by poor delivery techniques. A novel drug delivery system is being developed in our laboratory that can provide localized release of therapeutically relevant molecules from an injectable hydrogel. Design criteria were established for the hydrogel to be--injectable, fast-gelling, biocompatible, biodegradable and able to release biologically active therapeutics when injected into the intrathecal space that surrounds the spinal cord. This novel way of localized drug delivery to the spinal cord was tested first with a collagen gel and then with a new hydrogel blend of hyaluronan and methylcellulose (HAMC). The underlying principle that this novel methodology is both safe and able to provide localized delivery was proven with a fast gelling collagen solution. Using a recombinant human epidermal growth factor, rhEGF, dispersed in collagen, we demonstrated localized release to the injured spinal cord. We extended this technology to other fast-gelling systems and found that HAMC was injectable due to the shear thinning property of hyaluronan (HA), biocompatible and had some therapeutic benefit when injected into the intrathecal space using a compression injury model in rats.
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Affiliation(s)
- Molly S Shoichet
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Donnelly Center for Cellular and Biomolecular Research, Toronto, ON, M5S 3E1, Canada.
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Hou CH, Tzeng JI, Chen YW, Lin CN, Lin MT, Tu CH, Wang JJ. Dextromethorphan, 3-methoxymorphinan, and dextrorphan have local anaesthetic effect on sciatic nerve blockade in rats. Eur J Pharmacol 2006; 544:10-6. [PMID: 16844109 DOI: 10.1016/j.ejphar.2006.06.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2006] [Revised: 05/24/2006] [Accepted: 06/09/2006] [Indexed: 10/24/2022]
Abstract
Dextromethorphan has been used as an antitussive for more than 40 years and is considered a drug with a good margin of safety. The aim of the study was to evaluate whether dextromethorphan and its metabolites--3-methoxymorphinan and dextrorphan--had local anaesthetic effects. Using a method of sciatic nerve blockade in rats, the potencies and durations of actions of dextromethorphan and its metabolites on sciatic nerve blockades of motor function, proprioception, and nociception were evaluated. Lidocaine was used as control. We found that dextromethorphan and its metabolites produced dose-related local anaesthetic effects on sciatic nerve blockades of motor function, proprioception, and nociception. The ranks of potencies were lidocaine>dextromethorphan>3-methoxymorphinan>dextrorphan (P<0.01 for each comparison). Under an equi-potent basis, dextrorphan and 3-methoxymorphinan had durations of actions longer than that of lidocaine (P<0.05 for each comparison). Co-administration of dextromethorphan or its metabolites with lidocaine produced an additive effect on sciatic nerve blockades. In conclusion, dextromethorphan and its metabolites - 3-methoxymorphinan and dextrorphan- had a local anaesthetic effect on sciatic nerve blockades of motor function, proprioception and nociception with durations of actions longer than that of lidocaine. Co-administration of dextromethorphan and its metabolites produced an additive effect on sciatic nerve blockades.
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Affiliation(s)
- Chia-Hui Hou
- Department of Medical Research, Chi-Mei Medical Center, Tainan, Taiwan
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Suzuki K, Kazui T, Terada H, Umemura K, Ikeda Y, Bashar AHM, Yamashita K, Washiyama N, Suzuki T, Ohkura K, Yasuike J. Experimental study on the protective effects of edaravone against ischemic spinal cord injury. J Thorac Cardiovasc Surg 2005; 130:1586-92. [PMID: 16308003 DOI: 10.1016/j.jtcvs.2005.08.049] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2005] [Revised: 08/19/2005] [Accepted: 08/26/2005] [Indexed: 11/20/2022]
Abstract
OBJECTIVE Reactive free radical species are thought to be involved in ischemic spinal cord injury. We investigated the effects of edaravone (Mitsubishi Pharma Co, Tokyo, Japan), a free radical scavenger, on spinal ischemia-reperfusion injury in a rabbit model. We also sought to estimate free radicals in the spinal cord using the microdialysis method. METHODS Spinal cord ischemia was induced in New Zealand White rabbits. The animals were then divided into 4 groups. In the first experiment, which was carried out in group A (non-edaravone treated) and group B (edaravone treated), we assessed neurologic function and evaluated spinal cord histopathology. In the second experiment, which was performed in group C (non-edaravone treated) and group D (edaravone treated), we sequentially estimated the level of free radical species in the spinal cord with the microdialysis method. RESULTS In the first experiment group B showed better neurologic function than group A. The number of viable neurons in the spinal cord gray matter was also higher in group B than in group A. The second experiment revealed that the level of free radical species was lower in group D at 75, 90, and 150 minutes after the beginning of reperfusion compared with levels seen in group C. The appearance of free radical species in the latter group was found to have a biphasic pattern, with peaks at 75 and 150 minutes after the beginning of reperfusion. CONCLUSION Edaravone exerted a significant protective effect on the spinal cord against ischemia-reperfusion injury by suppressing the level of free radical species, which was demonstrated with the microdialysis method.
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Affiliation(s)
- Kazuchika Suzuki
- The First Department of Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan.
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Gupta D, Tator CH, Shoichet MS. Fast-gelling injectable blend of hyaluronan and methylcellulose for intrathecal, localized delivery to the injured spinal cord. Biomaterials 2005; 27:2370-9. [PMID: 16325904 DOI: 10.1016/j.biomaterials.2005.11.015] [Citation(s) in RCA: 412] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2005] [Accepted: 11/09/2005] [Indexed: 10/25/2022]
Abstract
Strategies for spinal cord injury repair are limited, in part, by poor drug delivery techniques. A novel drug delivery system (DDS) is being developed in our laboratory that can provide localized release of growth factors from an injectable gel. The gel must be fast-gelling, non-cell adhesive, degradable, and biocompatible as an injectable intrathecal DDS. A gel that meets these design criteria is a blend of hyaluronan and methylcellulose (HAMC). Unlike other injectable gels, HAMC is already at the gelation point prior to injection. It is injectable due to its shear-thinning property, and its gel strength increases with temperature. In vivo rat studies show that HAMC is biocompatible within the intrathecal space for 1 month, and may provide therapeutic benefit, in terms of behavior, as measured by the Basso, Beattie and Bresnahan (BBB) locomotor scale, and inflammation. These data suggest that HAMC is a promising gel for localized delivery of therapeutic agents to the injured spinal cord.
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Affiliation(s)
- Dimpy Gupta
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ont., Canada
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Shi E, Kazui T, Jiang X, Washiyama N, Suzuki K, Yamashita K, Terada H. NS-7, a novel Na+/Ca2+ channel blocker, prevents neurologic injury after spinal cord ischemia in rabbits. J Thorac Cardiovasc Surg 2005; 129:364-71. [PMID: 15678048 DOI: 10.1016/j.jtcvs.2004.05.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVE We investigated the neuroprotective effect of NS-7 (4-[4-fluorophenyl]-2-methyl-6- [5-piperidinopntyloxy] pyrimidine hydrochloride), a novel Na(+)/Ca(2+) channel blocker, on transient spinal cord ischemia in rabbits. METHODS Spinal cord ischemia was induced in New Zealand white rabbits by means of infrarenal aortic occlusion for 20 minutes. Four experimental groups were enrolled. A sham group (n = 3) underwent the same operation without aortic occlusion. A control group (n = 7) received only saline before occlusion. Group A (n = 8) received NS-7 (1 mg/kg) 15 minutes before ischemia, and group B (n = 8) received NS-7 (1 mg/kg) at the onset of reperfusion. Neurologic function was assessed 24 and 48 hours after the operation with modified Tarlov criteria. Spinal cords were harvested for histopathologic examination and in situ terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL staining). Spinal cord infarction was investigated with 2, 3, 5-triphenyltetrazonlium chloride staining. RESULTS Tarlov scoring demonstrated marked improvement in both group A and group B compared with the control group at 24 and 48 hours after the operation. Minimal histologic changes were found in lumbar spinal cords of the 2 NS-7-treated groups, whereas severe neuronal necrosis was shown in the control group. TUNEL-positive neurons and the infarct size of lumbar spinal cords were significantly reduced by NS-7 administered both before ischemia and at the onset of reperfusion. No significant difference was noted between group A and group B in terms of spinal cord protection. CONCLUSION These results indicate that NS-7 protects the spinal cord against ischemic injury by preventing both neuronal necrosis and apoptosis.
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Affiliation(s)
- Enyi Shi
- First Department of Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan
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