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Hirahara AM, Khan MS, Ishidoya Y, Smego D, Roman O, Ranjan R, Krueger L, Hoareau G, Selzman CH, Dosdall DJ. Canine Model of Ischemia-Induced Ventricular Tachycardia. J Surg Res 2024; 293:196-203. [PMID: 37778087 PMCID: PMC10840854 DOI: 10.1016/j.jss.2023.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 08/16/2023] [Accepted: 09/05/2023] [Indexed: 10/03/2023]
Abstract
INTRODUCTION Despite advances in antiarrhythmia therapies, ventricular tachycardia (VT) is a leading cause of sudden cardiac death. Investigation into the characteristics and new treatments for this arrhythmia is required to improve outcomes and a reproducible model of VT would be useful in these endeavors. We therefore created a canine model of ischemia-induced VT. MATERIALS AND METHODS A pacing lead was implanted in the right ventricle in canines (n = 13) and the left anterior descending artery was occluded in two locations for 2 h and subsequently released to create an ischemia-reperfusion injury. In the 10 dogs that survived the first 48 h following the initial study, a terminal study was conducted 4-7 d later and VT was induced using premature stimulation or burst pacing through the right ventricle lead. The arrhythmia was terminated using either antitachycardia pacing or a defibrillatory shock. Multiple inductions into sustained VT were attempted. RESULTS Sustained VT was induced in eight of 10 dogs with an average cycle length of 335 ± 70 bpm. Multiple episodes of VT were induced. Episodes of VT exhibited different electrocardiogram morphologies and cycle lengths in individual animals. CONCLUSIONS This canine model provides a consistent technique for inducing multiple episodes of sustained VT. It may be useful for investigating VT mechanisms and testing novel therapeutics and treatments for patients with VT.
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Affiliation(s)
- Annie M Hirahara
- Department of Biomedical Engineering, University of Utah, Salt Lake City, Utah; Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah
| | - Muhammad S Khan
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah
| | - Yuki Ishidoya
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah
| | - Douglas Smego
- Division of Cardiothoracic Surgery, Department of Surgery, University of Utah, Salt Lake City, Utah
| | - Orvelin Roman
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah
| | - Ravi Ranjan
- Department of Biomedical Engineering, University of Utah, Salt Lake City, Utah; Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah; Division of Cardiovascular Medicine, Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - Lauren Krueger
- Office of Comparative Medicine, University of Utah, Salt Lake City, Utah
| | - Guillaume Hoareau
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah; Department of Emergency Medicine, University of Utah, Salt Lake City, Utah
| | - Craig H Selzman
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah; Division of Cardiothoracic Surgery, Department of Surgery, University of Utah, Salt Lake City, Utah
| | - Derek J Dosdall
- Department of Biomedical Engineering, University of Utah, Salt Lake City, Utah; Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah; Division of Cardiothoracic Surgery, Department of Surgery, University of Utah, Salt Lake City, Utah; Division of Cardiovascular Medicine, Department of Internal Medicine, University of Utah, Salt Lake City, Utah.
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Kawabata Y, Takai S, Sanematsu K, Yoshida R, Kawabata F, Shigemura N. The Antiarrhythmic Drug Flecainide Enhances Aversion to HCl in Mice. eNeuro 2023; 10:ENEURO.0048-23.2023. [PMID: 37696662 PMCID: PMC10515741 DOI: 10.1523/eneuro.0048-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 08/21/2023] [Accepted: 09/04/2023] [Indexed: 09/13/2023] Open
Abstract
Drug-induced taste disorders reduce quality of life, but little is known about the molecular mechanisms by which drugs induce taste disturbances. In this study, we investigated the short-term and long-term effects of the antiarrhythmic drug flecainide, which is known to cause taste dysfunction. Analyses of behavioral responses (licking tests) revealed that mice given a single intraperitoneal injection of flecainide exhibited a significant reduction in preference for a sour tastant (HCl) but not for other taste solutions (NaCl, quinine, sucrose, KCl and monopotassium glutamate) when compared with controls. Mice administered a single dose of flecainide also had significantly higher taste nerve responses to HCl but not to other taste solutions. Compared with controls, mice administered flecainide once-daily for 30 d showed a reduced preference for HCl without any changes in the behavioral responses to other taste solutions. The electrophysiological experiments using HEK293T cells transiently expressing otopetrin-1 (Otop1; the mouse sour taste receptor) showed that flecainide did not alter the responses to HCl. Taken together, our results suggest that flecainide specifically enhances the response to HCl in mice during short-term and long-term administration. Although further studies will be needed to elucidate the molecular mechanisms, these findings provide new insights into the pathophysiology of drug-induced taste disorders.
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Affiliation(s)
- Yuko Kawabata
- Section of Oral Neuroscience, Graduate School of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
| | - Shingo Takai
- Section of Oral Neuroscience, Graduate School of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
| | - Keisuke Sanematsu
- Section of Oral Neuroscience, Graduate School of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
- Research and Development Center for Five-Sense Devices, Kyushu University, Fukuoka 819-0395, Japan
- Oral Health/Brain Health/Total Health Research Center, Graduate School of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
| | - Ryusuke Yoshida
- Department of Oral Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8525, Japan
| | - Fuminori Kawabata
- Physiology of Domestic Animals, Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki 036-8561, Japan
| | - Noriatsu Shigemura
- Section of Oral Neuroscience, Graduate School of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
- Research and Development Center for Five-Sense Devices, Kyushu University, Fukuoka 819-0395, Japan
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Zhou SF, Liu JP, Chowbay B. Polymorphism of human cytochrome P450 enzymes and its clinical impact. Drug Metab Rev 2009; 41:89-295. [PMID: 19514967 DOI: 10.1080/03602530902843483] [Citation(s) in RCA: 502] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Pharmacogenetics is the study of how interindividual variations in the DNA sequence of specific genes affect drug response. This article highlights current pharmacogenetic knowledge on important human drug-metabolizing cytochrome P450s (CYPs) to understand the large interindividual variability in drug clearance and responses in clinical practice. The human CYP superfamily contains 57 functional genes and 58 pseudogenes, with members of the 1, 2, and 3 families playing an important role in the metabolism of therapeutic drugs, other xenobiotics, and some endogenous compounds. Polymorphisms in the CYP family may have had the most impact on the fate of therapeutic drugs. CYP2D6, 2C19, and 2C9 polymorphisms account for the most frequent variations in phase I metabolism of drugs, since almost 80% of drugs in use today are metabolized by these enzymes. Approximately 5-14% of Caucasians, 0-5% Africans, and 0-1% of Asians lack CYP2D6 activity, and these individuals are known as poor metabolizers. CYP2C9 is another clinically significant enzyme that demonstrates multiple genetic variants with a potentially functional impact on the efficacy and adverse effects of drugs that are mainly eliminated by this enzyme. Studies into the CYP2C9 polymorphism have highlighted the importance of the CYP2C9*2 and *3 alleles. Extensive polymorphism also occurs in other CYP genes, such as CYP1A1, 2A6, 2A13, 2C8, 3A4, and 3A5. Since several of these CYPs (e.g., CYP1A1 and 1A2) play a role in the bioactivation of many procarcinogens, polymorphisms of these enzymes may contribute to the variable susceptibility to carcinogenesis. The distribution of the common variant alleles of CYP genes varies among different ethnic populations. Pharmacogenetics has the potential to achieve optimal quality use of medicines, and to improve the efficacy and safety of both prospective and currently available drugs. Further studies are warranted to explore the gene-dose, gene-concentration, and gene-response relationships for these important drug-metabolizing CYPs.
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Affiliation(s)
- Shu-Feng Zhou
- School of Health Sciences, RMIT University, Bundoora, Victoria, Australia.
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Bechtold DA, Kapoor R, Smith KJ. Axonal protection using flecainide in experimental autoimmune encephalomyelitis. Ann Neurol 2004; 55:607-16. [PMID: 15122700 DOI: 10.1002/ana.20045] [Citation(s) in RCA: 154] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Axonal degeneration is a major cause of permanent neurological deficit in multiple sclerosis (MS), but no current therapies for the disease are known to be effective at axonal protection. Here, we examine the ability of a sodium channel-blocking agent, flecainide, to reduce axonal degeneration in an experimental model of MS, chronic relapsing experimental autoimmune encephalomyelitis (CR-EAE). Rats with CR-EAE were treated with flecainide or vehicle from either 3 days before or 7 days after inoculation (dpi) until termination of the experiment at 28 to 30 dpi. Morphometric examination of neurofilament-labeled axons in the spinal cord of CR-EAE animals showed that both flecainide treatment regimens resulted in significantly higher numbers of axons surviving the disease (83 and 98% of normal) compared with controls (62% of normal). These findings indicate that flecainide and similar agents may provide a novel therapy aimed at axonal protection in MS and other neuroinflammatory disorders.
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Affiliation(s)
- David A Bechtold
- Department of Neuroimmunology, King's College, London, United Kingdom
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Gal J, Desai DM, Meyer-Lehnert S. Reversed-phase LC resolutions of chiral antiarrhythmic agents via derivatization with homochiral isothiocyanates. Chirality 1990; 2:43-51. [PMID: 2119207 DOI: 10.1002/chir.530020107] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The search for new antiarrhythmic agents has been intense, because the established drugs for the treatment of cardiac arrhythmias are neither uniformly effective nor well-tolerated. Among the recently introduced new antiarrhythmic agents are tocainide (TOC), mexiletine (MEX), flecainide (FLE), and propafenone (PRO). Each of these drugs is a chiral amine used clinically as the racemic mixture. We have examined the high-performance liquid chromatographic chiral resolution of the above four drugs via derivatization with homochiral derivatizing agents (HDAs). The amino functionality of the drugs was reacted with four homochiral isothiocyanates, 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl isothiocyanate (TAGIT), (R)-alpha-methylbenzyl isothiocyanate (RAMBI), (S)-1-(1-naphthyl)ethyl isothiocyanate (SNEIT), and (R)-1-(2-naphthyl)ethyl isothiocyanate (RBEIT). Complete separation of the two peaks (resolution factor R = 1.5) was achieved with all four HDAs for TOC, with TAGIT, RBEIT, and RAMBI for MEX, with TAGIT and SNEIT for PRO, and only with TAGIT for FLE. SNEIT was used to develop analytical procedures for the determination of the enantiomeric composition of TOC in human urine and blood serum. The four HDAs offer several advantages over many other HDAs and should be useful in studies of enantioselective drug action and disposition.
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Affiliation(s)
- J Gal
- Division of Clinical Pharmacology, University of Colorado School of Medicine, Denver 80262
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Feinfeld DA, Frishman WH. Renal Considerations in Cardiovascular Drug Therapy. Cardiol Clin 1987. [DOI: 10.1016/s0733-8651(18)30520-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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