title: (±)3,4-methylenedioxyamphetamine inhibits the TEA-sensitive K⁺ current in the hippocampal neuron and the Kv2.1 current expressed in H1355 cells.
abstract: The whole-cell patch clamp method was used to study the effects of (±)3,4-methylenedioxyamphetamine (MDA) in hippocampal CA1 neurons from neonatal rats and in lung epithelial H1355 cells expressing Kv2.1. Extracellular application of MDA (30 μM) induced bursts of action potentials in hippocampal CA1 neurons exhibiting single spike action potentials without a bursting firing pattern, and promoted action potential bursts in hippocampal CA1 neurons exhibiting bursting firing of action potentials. Whereas MDA (30 and 100 μM) markedly decreased the delayed outward current in hippocampal CA1 neurons, MDA (100 μM) only slightly decreased the fast-inactivating K(+) current (I(A)) current. Furthermore, MDA (100 μM) substantially decreased the delayed outward current in the presence of 4-aminopyridine (4-AP; 3 mM), but did not significantly decrease the delayed outward current in the presence of tetraethylammonium (TEA; 30 mM). MDA (100 μM) also inhibited the current in H1355 cells expressing Kv2.1. Our results have shown that MDA inhibits the TEA-sensitive K(+) current in the hippocampus and the Kv2.1 current expressed in H1355 cells. These effects may contribute to the pharmacological and toxicological effects of MDA.
authors.affiliation: Department of Health Industry Management, Kainan University, Taoyuan, Taiwan.
authors.forename: Chia-Hsien
authors.initials: CH
authors.lastname: Lin
authors.affiliation: School of Chinese Medicine, China Medical University, Taichung, Taiwan.
authors.forename: Chin-Tsang
authors.initials: CT
authors.lastname: Yang
authors.affiliation: Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Ming-Cheng
authors.initials: MC
authors.lastname: Tsai
authors.affiliation: Graduate Institute of Acupuncture Science, China Medical University, Taichung, Taiwan.
authors.forename: Ya-Ting
authors.initials: YT
authors.lastname: Wu
authors.affiliation: Graduate Institute of Acupuncture Science, China Medical University, Taichung, Taiwan.
authors.forename: Iona
authors.initials: I
authors.lastname: MacDonald
authors.affiliation: Graduate Institute of Neural and Cognitive Sciences, China Medical University, Taichung, Taiwan.
authors.forename: Mei-Ling
authors.initials: ML
authors.lastname: Wang
authors.affiliation: Department of Applied Mathematics, College of Science, Chung Yuan Christian University, Chung Li, Taiwan.
authors.forename: Chien-Hua
authors.initials: CH
authors.lastname: Wu
authors.affiliation: Graduate Institute of Neural and Cognitive Sciences, China Medical University, Taichung, Taiwan. Electronic address: ymleung@mail.cmu.edu.tw.
authors.forename: Yuk-Man
authors.initials: YM
authors.lastname: Leung
authors.affiliation: Graduate Institute of Acupuncture Science, China Medical University, Taichung, Taiwan. Electronic address: yihungchen@mail.cmu.edu.tw.
authors.forename: Yi-Hung
authors.initials: YH
authors.lastname: Chen
mesh_terms: D015104:3,4-Methylenedioxyamphetamine / Q000494:pharmacology*; D000818:Animals; D000831:Animals, Newborn; D002460:Cell Line; D005786:Gene Expression Regulation; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D026902:Potassium Channel Blockers / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D020545:Respiratory Mucosa / Q000187:drug effects / Q000378:metabolism*; D051669:Shab Potassium Channels / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D019789:Tetraethylammonium / Q000494:pharmacology*
chemical_list: C496991:Kcnb1 protein, rat; D026902:Potassium Channel Blockers; D051669:Shab Potassium Channels; D015104:3,4-Methylenedioxyamphetamine; D019789:Tetraethylammonium
keywords: (±)3,4-Methylenedioxyamphetamine; Action potentials; Hippocampal neuron; K(+) current