title: Oxidized low density lipoproteins exert arrhythmogenic effects in rabbit Purkinje fibers.
abstract: The electrophysiological effects of oxidized low density lipoproteins (ox-LDLs) have been studied in rabbit Purkinje fibers using standard microelectrode techniques, in comparison with native LDLs (n-LDLs) and lysophosphatidylcholine (LPC). At the concentration of 100 micrograms protein/ml, ox-LDL but never n-LDL induced the abrupt occurrence of abnormal electrical activities during the basic stimulation of 1 Hz (6/13 fibers) and the development of either early afterdepolarizations (6/13 fibers) or abnormal automaticity (4/13 fibers) at low frequencies (0.1 and 0.03 Hz). Short trains of rapid stimulation (2, 3, 4 and 5 Hz) did not trigger delayed afterdepolarizations. However, early afterhyperpolarizations were commonly seen after each action potential. 30 microM LPC caused quite similar electrophysiological derangements. The results suggest that ox-LDLs may exert arrhythmogenic effects partly explained by their LPC content.
authors.affiliation: Laboratoire de Pharmacologie, Faculté de Médecine, Lille, France.
authors.forename: M M
authors.initials: MM
authors.lastname: Adamantidis
authors.forename: L
authors.initials: L
authors.lastname: Moreau-Guedon
authors.forename: F
authors.initials: F
authors.lastname: Martin-Nizard
authors.forename: H
authors.initials: H
authors.lastname: Sqalli-Houssaini
authors.forename: P
authors.initials: P
authors.lastname: Duriez
authors.forename: J C
authors.initials: JC
authors.lastname: Fruchart
authors.forename: B
authors.initials: B
authors.lastname: Dupuis
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D004558:Electric Stimulation; D006339:Heart Rate / Q000187:drug effects*; D006352:Heart Ventricles; D006801:Humans; D066298:In Vitro Techniques; D008077:Lipoproteins, LDL / Q000097:blood / Q000302:isolation & purification / Q000494:pharmacology*; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D010084:Oxidation-Reduction; D011690:Purkinje Fibers / Q000187:drug effects / Q000502:physiology*; D011817:Rabbits
chemical_list: D008077:Lipoproteins, LDL