title: Organic cation transporter 3 contributes to norepinephrine uptake into perivascular adipose tissue.
abstract: Perivascular adipose tissue (PVAT) reduces vasoconstriction to norepinephrine (NE). A mechanism by which PVAT could function to reduce vascular contraction is by decreasing the amount of NE to which the vessel is exposed. PVATs from male Sprague-Dawley rats were used to test the hypothesis that PVAT has a NE uptake mechanism. NE was detected by HPLC in mesenteric PVAT and isolated adipocytes. Uptake of NE (10 μM) in mesenteric PVAT was reduced by the NE transporter (NET) inhibitor nisoxetine (1 μM, 73.68 ± 7.62%, all values reported as percentages of vehicle), the 5-hydroxytryptamine transporter (SERT) inhibitor citalopram (100 nM) with the organic cation transporter 3 (OCT3) inhibitor corticosterone (100 μM, 56.18 ± 5.21%), and the NET inhibitor desipramine (10 μM) with corticosterone (100 μM, 61.18 ± 6.82%). Aortic PVAT NE uptake was reduced by corticosterone (100 μM, 53.01 ± 10.96%). Confocal imaging of mesenteric PVAT stained with 4-[4-(dimethylamino)-styrl]-N-methylpyridinium iodide (ASP(+)), a fluorescent substrate of cationic transporters, detected ASP(+) uptake into adipocytes. ASP(+) (2 μM) uptake was reduced by citalopram (100 nM, 66.68 ± 6.43%), corticosterone (100 μM, 43.49 ± 10.17%), nisoxetine (100 nM, 84.12 ± 4.24%), citalopram with corticosterone (100 nM and 100 μM, respectively, 35.75 ± 4.21%), and desipramine with corticosterone (10 and 100 μM, respectively, 50.47 ± 5.78%). NET protein was not detected in mesenteric PVAT adipocytes. Expression of Slc22a3 (OCT3 gene) mRNA and protein in PVAT adipocytes was detected by RT-PCR and immunocytochemistry, respectively. These end points support the presence of a transporter-mediated NE uptake system within PVAT with a potential mediator being OCT3.
authors.affiliation: Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan; and ayalalop@msu.edu.
authors.forename: Nadia
authors.identifier: http://orcid.org/0000-0001-8000-3997
authors.initials: N
authors.lastname: Ayala-Lopez
authors.affiliation: Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan; and.
authors.forename: William F
authors.initials: WF
authors.lastname: Jackson
authors.affiliation: Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan; and.
authors.forename: Robert
authors.initials: R
authors.lastname: Burnett
authors.affiliation: Department of Chemistry, University of Miami, Coral Gables, Florida.
authors.forename: James N
authors.initials: JN
authors.lastname: Wilson
authors.affiliation: Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan; and.
authors.forename: Janice M
authors.initials: JM
authors.lastname: Thompson
authors.affiliation: Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan; and.
authors.forename: Stephanie W
authors.initials: SW
authors.lastname: Watts
mesh_terms: D017667:Adipocytes / Q000187:drug effects / Q000378:metabolism*; D018759:Adrenergic Uptake Inhibitors / Q000494:pharmacology; D000818:Animals; D001013:Aorta, Thoracic; D001692:Biological Transport; D002851:Chromatography, High Pressure Liquid; D003345:Corticosterone / Q000494:pharmacology; D007150:Immunohistochemistry; D050152:Intra-Abdominal Fat / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008638:Mesenteric Arteries; D018613:Microscopy, Confocal; D009638:Norepinephrine / Q000378:metabolism*; D050484:Norepinephrine Plasma Membrane Transport Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D029362:Organic Anion Transporters, Sodium-Independent / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D018759:Adrenergic Uptake Inhibitors; D050484:Norepinephrine Plasma Membrane Transport Proteins; D029362:Organic Anion Transporters, Sodium-Independent; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; C482440:Sert1 protein, rat; C493226:Slc6a2 protein, rat; C114338:organic anion transport protein 3; D003345:Corticosterone; D009638:Norepinephrine
keywords: 4-[4-(dimethylamino)-styrl]-N-methylpyridinium iodide; adipocytes; catecholamines; high-performance liquid chromotography; norepinephrine uptake; perivascular adipose tissue