AJP - Endo Fuel your research with LabChart
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
QUICK SEARCH:   [advanced]


     

Am J Physiol Endocrinol Metab (February 1, 2005). doi:10.1152/ajpendo.00588.2004
This Article
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
288/6/E1120    most recent
00588.2004v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
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 Google Scholar
Google Scholar
Right arrow Articles by An, D.
Right arrow Articles by Rodrigues, B.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by An, D.
Right arrow Articles by Rodrigues, B.
Submitted on December 13, 2004
Accepted on January 27, 2005

{beta}-agonist stimulation produces changes in cardiac AMPK and coronary lumen LPL only during increased workload

Ding An1*, Girsh Kewalramani1, Dake Qi1, Thomas Pulinilkunnil1, Sanjoy Ghosh1, Ashraf Abrahani1, Rich Wambolt2, Michael Allard2, Sheila M. Innis3, and Brian Rodrigues1

1 Department of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada
2 Departments of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
3 Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada

* To whom correspondence should be addressed. E-mail: dingan{at}interchange.ubc.ca.

Given the importance of LPL in cardiac and vascular pathology, the objective of the present study was to investigate whether the {beta}-agonist isoproterenol (ISO) influences cardiac LPL. Incubation of quiescent cardiomyocytes with ISO for 60 minutes had no effect on basal, intracellular or heparin-releasable (HR) LPL activity. Similarly, ISO did not change HR-LPL in Langendorff isolated hearts that do not beat against an afterload. In the intact animal, LPL activity at the vascular lumen increased significantly in the ISO treated group, together with a substantial increase in rate pressure product. This LPL increase was likely via mechanisms regulated by activation of AMPK and inactivation of ACC280. In glucose-perfused hearts, simply switching from Langendorff to the isolated working heart (that beats against an afterload) induced increases in AMPK and ACC280 phosphorylation and enhanced HR-LPL activity. Provision of insulin and albumin-bound palmitic acid to the working heart was able to reverse these effects. In these hearts, introduction of ISO to the buffer perfusate duplicated the effects seen when this {beta}-agonist was given in vivo. Our data suggest that ISO can influence HR-LPL, only during conditions of increased workload, mechanical performance and excessive energy expenditure, and likely in an AMPK dependent manner.




This article has been cited by other articles:


Home page
 J. Exp. Biol.Home page
L. Magnoni, E. Vaillancourt, and J.-M. Weber
In vivo regulation of rainbow trout lipolysis by catecholamines
J. Exp. Biol., August 1, 2008; 211(15): 2460 - 2466.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
R. Saeedi, H. L. Parsons, R. B. Wambolt, K. Paulson, V. Sharma, J. R. B. Dyck, R. W. Brownsey, and M. F. Allard
Metabolic actions of metformin in the heart can occur by AMPK-independent mechanisms
Am J Physiol Heart Circ Physiol, June 1, 2008; 294(6): H2497 - H2506.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Endocrinol. Metab.Home page
G. Wu, L. Zhang, J. Gupta, G. Olivecrona, and T. Olivecrona
A transcription-dependent mechanism, akin to that in adipose tissue, modulates lipoprotein lipase activity in rat heart
Am J Physiol Endocrinol Metab, October 1, 2007; 293(4): E908 - E915.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
V. W. Dolinsky and J. R. B. Dyck
Role of AMP-activated protein kinase in healthy and diseased hearts
Am J Physiol Heart Circ Physiol, December 1, 2006; 291(6): H2557 - H2569.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
Visit Other APS Journals Online
Copyright © 2005 by the American Physiological Society.