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Saporin as a Commercial Reagent: Its Uses and Unexpected Impacts in the Biological Sciences—Tools from the Plant Kingdom. Toxins (Basel) 2022; 14:toxins14030184. [PMID: 35324681 PMCID: PMC8952126 DOI: 10.3390/toxins14030184] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 02/23/2022] [Accepted: 02/23/2022] [Indexed: 02/02/2023] Open
Abstract
Saporin is a ribosome-inactivating protein that can cause inhibition of protein synthesis and causes cell death when delivered inside a cell. Development of commercial Saporin results in a technology termed ‘molecular surgery’, with Saporin as the scalpel. Its low toxicity (it has no efficient method of cell entry) and sturdy structure make Saporin a safe and simple molecule for many purposes. The most popular applications use experimental molecules that deliver Saporin via an add-on targeting molecule. These add-ons come in several forms: peptides, protein ligands, antibodies, even DNA fragments that mimic cell-binding ligands. Cells that do not express the targeted cell surface marker will not be affected. This review will highlight some newer efforts and discuss significant and unexpected impacts on science that molecular surgery has yielded over the last almost four decades. There are remarkable changes in fields such as the Neurosciences with models for Alzheimer’s Disease and epilepsy, and game-changing effects in the study of pain and itch. Many other uses are also discussed to record the wide-reaching impact of Saporin in research and drug development.
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Xiong L, Liu Y, Zhou M, Wang G, Quan D, Shen C, Shuai W, Kong B, Huang C, Huang H. Targeted ablation of cardiac sympathetic neurons improves ventricular electrical remodelling in a canine model of chronic myocardial infarction. Europace 2019; 20:2036-2044. [PMID: 29860489 DOI: 10.1093/europace/euy090] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 04/05/2018] [Indexed: 12/25/2022] Open
Abstract
Aims The purpose of this study was to evaluate the cardiac electrophysiologic effects of targeted ablation of cardiac sympathetic neurons (TACSN) in a canine model of chronic myocardial infarction (MI). Methods and results Thirty-eight anaesthetized dogs were randomly assigned into the sham-operated, MI, and MI-TACSN groups, respectively. Myocardial infarction-targeted ablation of cardiac sympathetic neuron was induced by injecting cholera toxin B subunit-saporin compound in the left stellate ganglion (LSG). Five weeks after surgery, the cardiac function, heart rate variability (HRV), ventricular electrophysiological parameters, LSG function and neural activity, serum norepinephrine (NE), nerve growth factor (NGF), and brain natriuretic peptide (BNP) levels were measured. Cardiac sympathetic innervation was determined with immunofluorescence staining of growth associated protein-43 (GAP43) and tyrosine hydroxylase (TH). Compared with MI group, TACSN significantly improved HRV, attenuated LSG function and activity, prolonged corrected QT interval, decreased Tpeak-Tend interval, prolonged ventricular effective refractory period (ERP), and action potential duration (APD), decreased the slopes of APD restitution curves, suppressed the APD alternans, increased ventricular fibrillation threshold, and reduced serum NE, NGF, and BNP levels. Moreover, the densities of GAP43 and TH-positive nerve fibres in the infarcted border zone in the MI-TACSN group were lower than those in the MI group. Conclusion Targeted ablation of cardiac sympathetic neuron attenuates sympathetic remodelling and improves ventricular electrical remodelling in the chronic phase of MI. These data suggest that TACSN may be a novel approach to treating ventricular arrhythmias.
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Affiliation(s)
- Liang Xiong
- Department of Cardiology, Renmin Hospital of Wuhan University, No.238 Jiefang Road, Wuchang, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, No.238 Jiefang Road, Wuchang, Wuhan, China.,Hubei Key Laboratory of Cardiology, No.238 Jiefang Road, Wuchang, Wuhan, China
| | - Yu Liu
- Department of Cardiology, Renmin Hospital of Wuhan University, No.238 Jiefang Road, Wuchang, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, No.238 Jiefang Road, Wuchang, Wuhan, China.,Hubei Key Laboratory of Cardiology, No.238 Jiefang Road, Wuchang, Wuhan, China
| | - Mingmin Zhou
- Department of Cardiology, Renmin Hospital of Wuhan University, No.238 Jiefang Road, Wuchang, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, No.238 Jiefang Road, Wuchang, Wuhan, China.,Hubei Key Laboratory of Cardiology, No.238 Jiefang Road, Wuchang, Wuhan, China
| | - Guangji Wang
- Department of Cardiology, Renmin Hospital of Wuhan University, No.238 Jiefang Road, Wuchang, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, No.238 Jiefang Road, Wuchang, Wuhan, China.,Hubei Key Laboratory of Cardiology, No.238 Jiefang Road, Wuchang, Wuhan, China
| | - Dajun Quan
- Department of Cardiology, Renmin Hospital of Wuhan University, No.238 Jiefang Road, Wuchang, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, No.238 Jiefang Road, Wuchang, Wuhan, China.,Hubei Key Laboratory of Cardiology, No.238 Jiefang Road, Wuchang, Wuhan, China
| | - Caijie Shen
- Department of Cardiology, Renmin Hospital of Wuhan University, No.238 Jiefang Road, Wuchang, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, No.238 Jiefang Road, Wuchang, Wuhan, China.,Hubei Key Laboratory of Cardiology, No.238 Jiefang Road, Wuchang, Wuhan, China
| | - Wei Shuai
- Department of Cardiology, Renmin Hospital of Wuhan University, No.238 Jiefang Road, Wuchang, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, No.238 Jiefang Road, Wuchang, Wuhan, China.,Hubei Key Laboratory of Cardiology, No.238 Jiefang Road, Wuchang, Wuhan, China
| | - Bin Kong
- Department of Cardiology, Renmin Hospital of Wuhan University, No.238 Jiefang Road, Wuchang, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, No.238 Jiefang Road, Wuchang, Wuhan, China.,Hubei Key Laboratory of Cardiology, No.238 Jiefang Road, Wuchang, Wuhan, China
| | - Congxin Huang
- Department of Cardiology, Renmin Hospital of Wuhan University, No.238 Jiefang Road, Wuchang, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, No.238 Jiefang Road, Wuchang, Wuhan, China.,Hubei Key Laboratory of Cardiology, No.238 Jiefang Road, Wuchang, Wuhan, China
| | - He Huang
- Department of Cardiology, Renmin Hospital of Wuhan University, No.238 Jiefang Road, Wuchang, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, No.238 Jiefang Road, Wuchang, Wuhan, China.,Hubei Key Laboratory of Cardiology, No.238 Jiefang Road, Wuchang, Wuhan, China
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3
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Hanna P, Rajendran PS, Shivkumar K. Neural ablation to treat ventricular arrhythmias. Europace 2018; 20:1880-1881. [PMID: 29931207 PMCID: PMC6275468 DOI: 10.1093/europace/euy134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Peter Hanna
- University of California Los Angeles (UCLA) Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, David Geffen School of Medicine, UCLA, 100 UCLA Medical Plaza, Suite 660, Los Angeles, CA, USA
- Molecular, Cellular, and Integrative Physiology Program, David Geffen School of Medicine, UCLA, 650 Charles E Young Drive South, CHS A2-237, Los Angeles, CA, USA
| | - Pradeep S Rajendran
- University of California Los Angeles (UCLA) Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, David Geffen School of Medicine, UCLA, 100 UCLA Medical Plaza, Suite 660, Los Angeles, CA, USA
- Molecular, Cellular, and Integrative Physiology Program, David Geffen School of Medicine, UCLA, 650 Charles E Young Drive South, CHS A2-237, Los Angeles, CA, USA
| | - Kalyanam Shivkumar
- University of California Los Angeles (UCLA) Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, David Geffen School of Medicine, UCLA, 100 UCLA Medical Plaza, Suite 660, Los Angeles, CA, USA
- Molecular, Cellular, and Integrative Physiology Program, David Geffen School of Medicine, UCLA, 650 Charles E Young Drive South, CHS A2-237, Los Angeles, CA, USA
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4
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Sung YL, Wu CE, Syu JY, Kuo TBJ, Li JY, Chen CW, Weng CH, Hsu WH, Chen SA, Hu YF, Lin SF. Effects of long-term exercise on arrhythmogenesis in aged hypertensive rats. Comput Biol Med 2018; 102:390-395. [PMID: 30144936 DOI: 10.1016/j.compbiomed.2018.08.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 07/24/2018] [Accepted: 08/13/2018] [Indexed: 12/16/2022]
Abstract
Chronic hypertension is a multifactorial disease that is highly associated with cardiovascular disorders. Physical activity, such as long-term exercise, is advocated as a treatment for hypertension, but the responses of different age groups to long-term exercise are unknown. We used aged spontaneous hypertensive rats (SHRs, 80 weeks old) to test the hypothesis that long-term exercise compensated for deficient autonomic control and reduced susceptibility to ventricular tachycardia (VT) and ventricular fibrillation (VF) in this animal model. The aged SHRs were divided into control and voluntary exercise groups. Ambulatory electrocardiography was recorded for the heart rate variability (HRV) analysis. Programmed stimulation was applied to exposed hearts to induce ventricular arrhythmia in situ. Then, the hearts were isolated for an optical mapping study. The results showed that increased HRV indices were broadly related to vagal dominance in the high-intensity exercise group. Exercise altered the electrical propagation dynamic properties, such as the action potential duration restitution (APDR). Furthermore, the VF inducibility decreased with increased exercise intensity. Taken together, our results suggest that long-term exercise reduces the risk of arrhythmogenesis in aged SHRs through enhanced vagal control and stabilized electrical dynamics.
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Affiliation(s)
- Yen-Ling Sung
- Institute of Biomedical Engineering, College of Electrical and Computer Engineering, National Chiao Tung University, Hsinchu, Taiwan
| | - Chih-En Wu
- Institute of Biomedical Engineering, College of Electrical and Computer Engineering, National Chiao Tung University, Hsinchu, Taiwan
| | - Jhen-Yang Syu
- Institute of Biomedical Engineering, College of Electrical and Computer Engineering, National Chiao Tung University, Hsinchu, Taiwan
| | - Terry B J Kuo
- Graduate Institute of Biomedical Informatics, Taipei Medical University, Taipei, Taiwan
| | - Jai-Yi Li
- Department of Health and Leisure Management, Yuanpei University of Medical Technology, Hsinchu, Taiwan
| | - Chieh-Wen Chen
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan
| | - Ching-Hui Weng
- Division of Cardiology, Department of Medicine, Taipei Veteran General Hospital, Taipei, Taiwan
| | - Wei-Hsuan Hsu
- Division of Cardiology, Department of Medicine, Taipei Veteran General Hospital, Taipei, Taiwan
| | - Shih-Ann Chen
- Division of Cardiology, Department of Medicine, Taipei Veteran General Hospital, Taipei, Taiwan; Faculty of Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Yu-Feng Hu
- Division of Cardiology, Department of Medicine, Taipei Veteran General Hospital, Taipei, Taiwan; Faculty of Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
| | - Shien-Fong Lin
- Institute of Biomedical Engineering, College of Electrical and Computer Engineering, National Chiao Tung University, Hsinchu, Taiwan
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5
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Xiong L, Liu Y, Zhou M, Wang G, Quan D, Shuai W, Shen C, Kong B, Huang C, Huang H. Targeted ablation of cardiac sympathetic neurons attenuates adverse postinfarction remodelling and left ventricular dysfunction. Exp Physiol 2018; 103:1221-1229. [PMID: 29928790 DOI: 10.1113/ep086928] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Accepted: 06/19/2018] [Indexed: 01/08/2023]
Affiliation(s)
- Liang Xiong
- Department of Cardiology; Renmin Hospital of Wuhan University; Wuhan China
- Cardiovascular Research Institute of Wuhan University; Wuhan China
- Hubei Key Laboratory of Cardiology; Wuhan China
| | - Yu Liu
- Department of Cardiology; Renmin Hospital of Wuhan University; Wuhan China
- Cardiovascular Research Institute of Wuhan University; Wuhan China
- Hubei Key Laboratory of Cardiology; Wuhan China
| | - Mingmin Zhou
- Department of Cardiology; Renmin Hospital of Wuhan University; Wuhan China
- Cardiovascular Research Institute of Wuhan University; Wuhan China
- Hubei Key Laboratory of Cardiology; Wuhan China
| | - Guangji Wang
- Department of Cardiology; Renmin Hospital of Wuhan University; Wuhan China
- Cardiovascular Research Institute of Wuhan University; Wuhan China
- Hubei Key Laboratory of Cardiology; Wuhan China
| | - Dajun Quan
- Department of Cardiology; Renmin Hospital of Wuhan University; Wuhan China
- Cardiovascular Research Institute of Wuhan University; Wuhan China
- Hubei Key Laboratory of Cardiology; Wuhan China
| | - Wei Shuai
- Department of Cardiology; Renmin Hospital of Wuhan University; Wuhan China
- Cardiovascular Research Institute of Wuhan University; Wuhan China
- Hubei Key Laboratory of Cardiology; Wuhan China
| | - Caijie Shen
- Department of Cardiology; Renmin Hospital of Wuhan University; Wuhan China
- Cardiovascular Research Institute of Wuhan University; Wuhan China
- Hubei Key Laboratory of Cardiology; Wuhan China
| | - Bin Kong
- Department of Cardiology; Renmin Hospital of Wuhan University; Wuhan China
- Cardiovascular Research Institute of Wuhan University; Wuhan China
- Hubei Key Laboratory of Cardiology; Wuhan China
| | - Congxin Huang
- Department of Cardiology; Renmin Hospital of Wuhan University; Wuhan China
- Cardiovascular Research Institute of Wuhan University; Wuhan China
- Hubei Key Laboratory of Cardiology; Wuhan China
| | - He Huang
- Department of Cardiology; Renmin Hospital of Wuhan University; Wuhan China
- Cardiovascular Research Institute of Wuhan University; Wuhan China
- Hubei Key Laboratory of Cardiology; Wuhan China
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Targeted ablation of cardiac sympathetic neurons: A promising approach to prevent sudden cardiac death. Int J Cardiol 2015; 202:425-6. [PMID: 26433164 DOI: 10.1016/j.ijcard.2015.09.049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 09/19/2015] [Indexed: 11/22/2022]
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7
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Lujan HL, DiCarlo SE. Cardiac output, at rest and during exercise, before and during myocardial ischemia, reperfusion, and infarction in conscious mice. Am J Physiol Regul Integr Comp Physiol 2013; 304:R286-95. [PMID: 23302959 DOI: 10.1152/ajpregu.00517.2012] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Multiple systems and regulatory strategies interact to control cardiac homeostasis. In fact, regulated systems, feedback controls, and redundant control mechanisms dominate in whole animals. Accordingly, molecular and cellular tools and techniques must be utilized in complex models with multiple systems and regulatory strategies to fully appreciate the physiological context. Currently, these techniques are mainly performed under conditions remote from the normal in vivo condition; thus, the extrapolation of molecular changes to the in vivo situation and the facilitation of translational aspect of the findings are limited. A major obstacle has been the reliance on preparations that do not mimic the clinical or physiological situation. This is particularly true regarding measurements of cardiac function in mice. To address these concerns, we used a permanently implanted Doppler ultrasonic flow probe on the ascending aorta and coronary artery occluder for repeated measurements of ascending aortic blood flow (cardiac output) in conscious mice, at rest and during exercise, before and during coronary artery occlusion/reperfusion and infarction. The conscious mouse model permits detailed monitoring of within-animal changes in cardiac function during myocardial ischemia, reperfusion, and infarction in an intact, complex model free of the confounding influences of anesthetics, surgical trauma, and restraint stress. Results from this study suggest that previous protocols may have overestimated resting baseline values and underestimated cardiac output reserve. Using these procedures in currently available spontaneous or engineered mouse mutants has the potential to be of major importance for advancing the concepts and methods that drive cardiovascular research.
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Affiliation(s)
- Heidi L Lujan
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA
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8
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Lujan HL, Janbaih H, Feng HZ, Jin JP, DiCarlo SE. Ventricular function during exercise in mice and rats. Am J Physiol Regul Integr Comp Physiol 2011; 302:R68-74. [PMID: 22012697 DOI: 10.1152/ajpregu.00340.2011] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The mouse has many advantages over other experimental models for the molecular investigation of left ventricular (LV) function. Accordingly, there is a keen interest in, as well as an intense need for, a conscious, chronically instrumented, freely moving mouse model for the determination of cardiac function. To address this need, we used a telemetry device for repeated measurements of LV function in conscious mice at rest and during exercise. For reference, we compared the responses in mice to the responses in identically instrumented conscious rats. The transmitter body of the telemetry device (rat PA-C40; mouse PA-C10; Data Sciences International, St. Paul, MN) was placed in the intraperitoneal space through a ventral abdominal approach (rat) or subcutaneously on the left flank (mouse). The pressure sensor, located within the tip of a catheter, was inserted into the left ventricle through an apical stab wound (18 gauge for rat; 21 gauge for mouse) for continuous, nontethered, recordings of pulsatile LV pressure. A minimum of 1 wk was allowed for recovery and for the animals to regain their presurgical weight. During the recovery period, the animals were handled, weighed, and acclimatized to the laboratory, treadmill, and investigators. Subsequently, LV parameters were recorded at rest and during a graded exercise test. The results document, for the first time, serial assessment of ventricular function during exercise in conscious mice and rats. This methodology may be adopted for advancing the concepts and ideas that drive cardiovascular research.
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Affiliation(s)
- Heidi L Lujan
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan 48201, USA
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Lujan HL, Palani G, DiCarlo SE. Structural neuroplasticity following T5 spinal cord transection: increased cardiac sympathetic innervation density and SPN arborization. Am J Physiol Regul Integr Comp Physiol 2010; 299:R985-95. [PMID: 20668234 DOI: 10.1152/ajpregu.00329.2010] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
When the spinal cord is injured at or below thoracic level 5 (T5), cardiovascular control is markedly unbalanced as the heart and blood vessels innervated by upper thoracic segments remain under brain stem control, whereas the vasculature of the lower body is affected by unregulated spinal reflexes. Importantly, the regulation of heart rate and cardiac function is abnormal after spinal cord injury (SCI) at T5 because sympathetic outflow to the heart is increased. An increase in tonic sympathetic outflow may be attributable to multiple mechanisms, such as increases in cardiac sympathetic innervation density, altered morphology of stellate ganglia neurons, and/or structural neuroplasticity of cardiac sympathetic preganglionic neurons (SPNs). Furthermore, these neuroplastic changes associated with SCI may be mediated by nerve growth factor (NGF). NGF is a neurotrophin that supports the survival and differentiation of sympathetic neurons and enhances target innervation. Therefore, we tested the hypothesis that T5 spinal cord transection (T5X) is associated with an increased left ventricular (LV) NGF content, LV sympathetic innervation density, and cardiac SPN arborization. In intact and paraplegic (9 wk posttransection) rats, LV NGF content (ELISA), LV sympathetic innervation density (tyrosine hydroxylase immunohistochemistry), and cardiac SPN arborization (cholera toxin B immunohistochemistry and Sholl Analysis) were determined. Paraplegia, compared with intact, significantly increased LV NGF content, LV sympathetic innervation density, and cardiac SPN arborization. Thus, altered autonomic behavior following SCI is associated with structural neuroplastic modifications.
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Affiliation(s)
- Heidi L Lujan
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan 48201, USA
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Lujan HL, Palani G, Peduzzi JD, DiCarlo SE. Targeted ablation of mesenteric projecting sympathetic neurons reduces the hemodynamic response to pain in conscious, spinal cord-transected rats. Am J Physiol Regul Integr Comp Physiol 2010; 298:R1358-65. [PMID: 20219868 PMCID: PMC2867526 DOI: 10.1152/ajpregu.00755.2009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Accepted: 03/05/2010] [Indexed: 11/22/2022]
Abstract
Individuals with spinal cord injuries above thoracic level 6 (T(6)) experience episodic bouts of life-threatening hypertension as part of a condition termed autonomic dysreflexia. The paroxysmal hypertension can be caused by a painful stimulus below the level of the injury. Targeted ablation of mesenteric projecting sympathetic neurons may reduce the severity of autonomic dysreflexia by reducing sympathetic activity. Therefore, cholera toxin B subunit (CTB) conjugated to saporin (SAP; a ribosomal inactivating protein that binds to and inactivates ribosomes) was injected into the celiac ganglion to test the hypothesis that targeted ablation of mesenteric projecting sympathetic neurons reduces the pressor response to pain in conscious, spinal cord-transected rats. Nine Sprague-Dawley male rats underwent a spinal cord transection between thoracic vertebrae 4 and 5. Following recovery (5 wk), all rats were instrumented with a radio telemetry device for recording arterial pressure and bilateral catheters in the gluteus maximus muscles for the infusion of hypertonic saline (hNa(+)Cl(-)). Subsequently, the hemodynamic responses to intramuscular injection of hNa(+)Cl(-) (100 microl and 250 microl, in random order) were determined. Following the experiments in the no celiac ganglia injected condition (NGI), rats received injections of CTB-SAP (n = 5) or CTB (n = 3) into the celiac ganglia. CTB-SAP rats, compared with NGI and CTB rats, had reduced pressor responses to hNa(+)Cl(-). Furthermore, the number of stained neurons in the celiac ganglia and spinal cord (segments T(6)-T(12)), was reduced in CTB-SAP rats. Thus, CTB-SAP retrogradely transported from the celiac ganglia is effective at ablating mesenteric projecting sympathetic neurons and reducing the pressor response to pain in spinal cord-transected rats.
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MESH Headings
- Animals
- Autonomic Dysreflexia/etiology
- Autonomic Dysreflexia/physiopathology
- Autonomic Dysreflexia/therapy
- Blood Pressure/drug effects
- Blood Pressure/physiology
- Cholera Toxin/pharmacology
- Consciousness
- Disease Models, Animal
- Ganglia, Spinal/drug effects
- Ganglia, Spinal/physiology
- Ganglia, Sympathetic/drug effects
- Ganglia, Sympathetic/physiopathology
- Heart Rate/drug effects
- Heart Rate/physiology
- Injections, Intramuscular
- Male
- Pain/complications
- Pain/physiopathology
- Rats
- Rats, Sprague-Dawley
- Ribosome Inactivating Proteins, Type 1/pharmacology
- Saline Solution, Hypertonic/pharmacology
- Saporins
- Spinal Cord Injuries/complications
- Spinal Cord Injuries/physiopathology
- Sympathectomy, Chemical
- Thoracic Vertebrae
- Visceral Afferents/drug effects
- Visceral Afferents/physiology
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Affiliation(s)
- Heidi L Lujan
- Department of Physiology, Wayne State University School of Medicine, 540 E. Canfield Ave., Detroit, MI 48201, USA
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Lujan HL, Palani G, Zhang L, DiCarlo SE. Targeted ablation of cardiac sympathetic neurons reduces the susceptibility to ischemia-induced sustained ventricular tachycardia in conscious rats. Am J Physiol Heart Circ Physiol 2010; 298:H1330-9. [PMID: 20173045 DOI: 10.1152/ajpheart.00955.2009] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The Cardiac Arrhythmia Suppression Trial demonstrated that antiarrhythmic drugs not only fail to prevent sudden cardiac death, but actually increase overall mortality. These findings have been confirmed in additional trials. The "proarrhythmic" effects of most currently available antiarrhythmic drugs makes it essential that we investigate novel strategies for the prevention of sudden cardiac death. Targeted ablation of cardiac sympathetic neurons may become a therapeutic option by reducing sympathetic activity. Thus cholera toxin B subunit (CTB) conjugated to saporin (a ribosomal inactivating protein that binds to and inactivates ribosomes; CTB-SAP) was injected into both stellate ganglia to test the hypothesis that targeted ablation of cardiac sympathetic neurons reduces the susceptibility to ischemia-induced, sustained ventricular tachycardia in conscious rats. Rats were randomly divided into three groups: 1) control (no injection); 2) bilateral stellate ganglia injection of CTB; and 3) bilateral stellate ganglia injection of CTB-SAP. CTB-SAP rats had a reduced susceptibility to ischemia-induced, sustained ventricular tachycardia. Associated with the reduced susceptibility to ventricular arrhythmias were a reduced number of stained neurons in the stellate ganglia and spinal cord (segments T(1)-T(4)), as well as a reduced left ventricular norepinephrine content and sympathetic innervation density. Thus CTB-SAP retrogradely transported from the stellate ganglia is effective at ablating cardiac sympathetic neurons and reducing the susceptibility to ventricular arrhythmias.
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Affiliation(s)
- Heidi L Lujan
- Wayne State University School of Medicine, 540 E. Canfield Ave., Detroit, MI 48201, USA.
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