title: Beta-blockade prevents ventricular failure following aortic regurgitation in rabbits.
abstract: This study investigated the effects of chronic beta-blockade on the pathophysiology of heart failure following induction of aortic regurgitation (AR). Nine rabbits with AR were administered propranolol continuously for 7 days (AR+P), 8 rabbits with AR received vehicle for the same period (AR+C), and 7 rabbits underwent sham operation. Cardiac output was lower and the left-ventricular end-diastolic pressure was higher in AR+C than in sham-operated rabbits, but there was no difference in the right-ventricular end-diastolic pressure between the two groups. Down-regulation of beta-adrenoceptors was observed in the left ventricle, but not in the right ventricle. All of these variables were reversed in AR+P. In left-ventricular failure produced by AR, (1) the augmentation of adrenergic drive occurred selectively in the left ventricle, and (2) propranolol blunted adrenergic drive and played a protective role against myocardial damage.
authors.affiliation: Department of Medicine, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Suzuki
authors.forename: T
authors.initials: T
authors.lastname: Yoshikawa
authors.forename: Y
authors.initials: Y
authors.lastname: Wainai
authors.forename: K
authors.initials: K
authors.lastname: Nagami
authors.forename: S
authors.initials: S
authors.lastname: Handa
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D001022:Aortic Valve Insufficiency / Q000188:drug therapy / Q000503:physiopathology*; D004195:Disease Models, Animal; D005260:Female; D015918:Infusion Pumps, Implantable; D007263:Infusions, Parenteral; D011433:Propranolol / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D011817:Rabbits; D011897:Random Allocation; D018754:Ventricular Dysfunction / Q000188:drug therapy / Q000503:physiopathology / Q000517:prevention & control*
chemical_list: D000319:Adrenergic beta-Antagonists; D011433:Propranolol