title: Effects of seven drugs of abuse on action potential repolarisation in sheep cardiac Purkinje fibres.
abstract: Seven drugs of abuse have been examined for effects on the action potential in sheep isolated cardiac Purkinje fibres. Phencyclidine (5 microM) induced a significant increase (30.7%) in action potential duration at 90% repolarisation (APD(90)). Similarly, 10 microM 3,4-methylenedioxymethamphetamine (MDMA, 'Ecstasy') induced a significant increase in APD(90) of 12.1%. Although Delta(9)-tetrahydrocannabinol (0.1 microM) induced a small, but statistically significant, 4.8% increase in APD(90), no effects were observed at 0.01 or 1 microM. Cocaethylene (10 microM) induced a significant shortening of APD(90) (-23.8%). Cocaine (up to 1 microM), (+)-methamphetamine ('Speed'; up to 5 microM), and the heroin metabolite, morphine (up to 5 microM), had no statistically significant effects. The possible significance of these findings is discussed in the context of other recognised cardiac effects of the tested drugs.
authors.affiliation: Biomedical Sciences, Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, UK. rdsheridan@dstl.gov.uk
authors.forename: Robert D
authors.initials: RD
authors.lastname: Sheridan
authors.forename: Simon R
authors.initials: SR
authors.lastname: Turner
authors.forename: Graham J
authors.initials: GJ
authors.lastname: Cooper
authors.forename: John E H
authors.initials: JE
authors.lastname: Tattersall
mesh_terms: D000200:Action Potentials / Q000187:drug effects*; D000818:Animals; D003042:Cocaine / Q000031:analogs & derivatives* / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D013759:Dronabinol / Q000494:pharmacology; D013287:Illicit Drugs / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D008694:Methamphetamine / Q000494:pharmacology; D009020:Morphine / Q000494:pharmacology; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000494:pharmacology; D010622:Phencyclidine / Q000494:pharmacology; D011690:Purkinje Fibers / Q000187:drug effects* / Q000502:physiology; D012756:Sheep; D013997:Time Factors
chemical_list: D013287:Illicit Drugs; D008694:Methamphetamine; D009020:Morphine; D013759:Dronabinol; C066444:cocaethylene; D003042:Cocaine; D010622:Phencyclidine; D018817:N-Methyl-3,4-methylenedioxyamphetamine