title: Organic cation/carnitine transporter family expression patterns in adult murine heart.
abstract: Organic cation/carnitine transporters transport carnitine, drugs, and xenobiotics (e.g. choline, acetylcarnitine, quinidine, and verapamil), and are expressed in muscle, heart, blood vessels, etc. To characterize expression patterns of mOctn1, -2, and -3 in adult murine heart, we applied our transporter-specific antibodies to mOctn1, -2, and -3, followed by secondary antibody and DAB peroxidase detection to adult murine heart sections counterstained with hematoxylin. All three transporters showed strong expression in cardiomyocytes, lamina fibrosa of cardiac valves, great arteries and intermuscular arterioles, and a striking differential expression in the vagal innervated sinoatrial and atrioventricular nodes. The hOCTN2 deficiency presents with carnitine-responsive cardiomyopathy. Octn1, -2, and -3 are expressed in many regions of murine heart with a pattern suggestive of potential roles in modulating myocardial bioenergetics, valvular function, and acetylcholine generation for parasympathetic vagal innervation of the cardiac conduction system. This distribution may play a role in the hypertrophic cardiomyopathy seen in hOCTN2 deficiency, and may also affect the absorption/elimination of organic cationic cardiac drugs.
authors.affiliation: Division of Neurology, Department of Pediatrics, Hospital for Sick Children, University of Toronto, Ontario, Canada.
authors.forename: Anne Marie
authors.initials: AM
authors.lastname: Lamhonwah
authors.forename: Jeannie
authors.initials: J
authors.lastname: Wong
authors.forename: Carolyn
authors.initials: C
authors.lastname: Tam
authors.forename: Lydia
authors.initials: L
authors.lastname: Mai
authors.forename: Ingrid
authors.initials: I
authors.lastname: Tein
mesh_terms: D000818:Animals; D001160:Arterioles / Q000378:metabolism; D001283:Atrioventricular Node / Q000378:metabolism; D002331:Carnitine / Q000378:metabolism; D002352:Carrier Proteins / Q000096:biosynthesis*; D002412:Cations / Q000378:metabolism; D006351:Heart Valves / Q000378:metabolism; D007150:Immunohistochemistry; D008565:Membrane Proteins / Q000096:biosynthesis*; D051379:Mice; D009206:Myocardium / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000378:metabolism; D027701:Organic Cation Transport Proteins / Q000096:biosynthesis*; D012849:Sinoatrial Node / Q000378:metabolism; D000074058:Solute Carrier Family 22 Member 5; D027981:Symporters
chemical_list: D002352:Carrier Proteins; D002412:Cations; D008565:Membrane Proteins; D027701:Organic Cation Transport Proteins; C498687:Slc22a21 protein, mouse; C491659:Slc22a4 protein, mouse; C492019:Slc22a5 protein, mouse; D000074058:Solute Carrier Family 22 Member 5; D027981:Symporters; D002331:Carnitine