Journal of Applied Physiology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Appl Physiol 91: 1627-1637, 2001;
8750-7587/01 $5.00
This Article
Right arrow Full Text Free
Right arrow Full Text (PDF) Free
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via ISI Web of Science (6)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Houle, M. S.
Right arrow Articles by Billman, G. E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Houle, M. S.
Right arrow Articles by Billman, G. E.
Vol. 91, Issue 4, 1627-1637, October 2001

Enhanced in vivo and in vitro contractile responses to beta 2-adrenergic receptor stimulation in dogs susceptible to lethal arrhythmias

Melanie S. Houle1, Ruth A. Altschuld2, and George E. Billman1

Departments of 1 Physiology and Cell Biology and 2 Molecular and Cellular Biochemistry, The Ohio State University, Columbus, Ohio 43210

The response to beta -adrenergic receptor (beta -AR) stimulation was evaluated in both isolated cardiomyocytes (video edge detection) and the intact animal (echocardiography) in dogs either susceptible (S) or resistant (R) to ventricular fibrillation induced by a 2-min coronary occlusion during the last minute of exercise. In the intact animal, velocity of circumferential fiber shortening (Vcf) was evaluated both before (n = 27, S = 12 and R = 15) and after myocardial infarction. Before infarction, increasing doses of isoproterenol provoked similar contractile and heart rate responses in each group of dogs. Either beta 1-AR (bisoprolol) or beta 2-AR (ICI-118551) antagonists reduced the isoproterenol response, with a larger reduction noted after the beta 1-AR blockade. In contrast, after infarction, isoproterenol induced a significantly larger Vcf and heart rate response in the susceptible animals that was eliminated by beta 2-AR blockade. The single-cell isotonic shortening response to isoproterenol (100 nM) was also larger in cells obtained from susceptible compared with resistant dogs and was reduced to a greater extent by beta 2-AR blockade in the susceptible dog myocytes (S, -48%, n = 6; R, -15%, n = 9). When considered together, these data suggest that myocardial infarction provoked an enhanced beta 2-AR response in susceptible, but not resistant, animals.

sudden cardiac death; beta -adrenergic receptors; myocardial ischemia; inotropy; contractility; ventricular fibrillation


This article has been cited by other articles:


Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
B. J. Holycross, M. Kukielka, Y. Nishijima, R. A. Altschuld, C. A. Carnes, and G. E. Billman
Exercise training normalizes beta-adrenoceptor expression in dogs susceptible to ventricular fibrillation
Am J Physiol Heart Circ Physiol, November 1, 2007; 293(5): H2702 - H2709.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
G. E. Billman, M. Kukielka, R. Kelley, M. Moustafa-Bayoumi, and R. A. Altschuld
Endurance exercise training attenuates cardiac beta2-adrenoceptor responsiveness and prevents ventricular fibrillation in animals susceptible to sudden death
Am J Physiol Heart Circ Physiol, June 1, 2006; 290(6): H2590 - H2599.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online