title: Effects of dronedarone and amiodarone on plasma thyroid hormones and on the basal and postischemic performance of the isolated rat heart.
abstract: The present study investigated the effects of dronedarone and amiodarone on plasma thyroid hormones and the possible consequences on the response of the heart to ischemia. Amiodarone (30 mg/kg/day per os) or dronedarone (30 mg/kg/day per os) were administered for 2 weeks in normal and thyroxine-treated animals (25 microg/100 g body weight od sc, for 2 weeks), while animals without amiodarone and dronedarone served as controls. Isolated rat hearts were perfused in a Langendorff mode and subjected to 20 and 30 min of zero-flow global ischemia followed by 45 min of reperfusion. Functional changes were assessed by measuring left ventricular developed pressure (LVDP) under resting conditions and in response to ischemia-reperfusion, LVDP%, as well as the severity of ischemic contracture. Amiodarone resulted in increased T4, T4/T3 and rT3, whereas dronedarone did not alter the thyroid hormone profile in normal animals. In thyroxine-treated animals, amiodarone increased T4/T3 ratio but T4, T3 and rT3 levels were not altered. Basal functional parameters and ischemic contracture did not change by amiodarone and/or dronedarone neither in normal nor in thyroxine-treated hearts. In normal hearts, postischemic functional recovery, LVDP%, was not altered by amiodarone or dronedarone administration. LVDP% was statistically higher in thyroxine-treated hearts than in normal and this beneficial effect was not abolished by amiodarone or dronedarone treatment.
authors.affiliation: Department of Pharmacology, University of Athens, 75 Mikras Asias Ave., 11527 Goudi, Greece. cpantos@cc.uoa.gr
authors.forename: Constantinos
authors.initials: C
authors.lastname: Pantos
authors.forename: Iordanis
authors.initials: I
authors.lastname: Mourouzis
authors.forename: Martine
authors.initials: M
authors.lastname: Delbruyère
authors.forename: Vassiliki
authors.initials: V
authors.lastname: Malliopoulou
authors.forename: Stylianos
authors.initials: S
authors.lastname: Tzeis
authors.forename: Demosthenis D
authors.initials: DD
authors.lastname: Cokkinos
authors.forename: Nikos
authors.initials: N
authors.lastname: Nikitas
authors.forename: Hariclia
authors.initials: H
authors.lastname: Carageorgiou
authors.forename: Dennis
authors.initials: D
authors.lastname: Varonos
authors.forename: Dennis
authors.initials: D
authors.lastname: Cokkinos
authors.forename: Dino
authors.initials: D
authors.lastname: Nisato
mesh_terms: D000638:Amiodarone / Q000031:analogs & derivatives* / Q000494:pharmacology* / Q000627:therapeutic use; D000818:Animals; D000077764:Dronedarone; D006321:Heart / Q000187:drug effects* / Q000502:physiology; D066298:In Vitro Techniques; D008297:Male; D017202:Myocardial Ischemia / Q000188:drug therapy / Q000503:physiopathology; D051381:Rats; D017208:Rats, Wistar; D013963:Thyroid Hormones / Q000097:blood*
chemical_list: D013963:Thyroid Hormones; D000077764:Dronedarone; D000638:Amiodarone