AJP - Heart AJP: Endocrinology and Metabolism
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Heart Circ Physiol 275: H1473-H1481, 1998;
0363-6135/98 $5.00
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
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 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 Pi, Y.
Right arrow Articles by Walker, J. W.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Pi, Y.
Right arrow Articles by Walker, J. W.
Vol. 275, Issue 4, H1473-H1481, October 1998

Role of intracellular Ca2+ and pH in positive inotropic response of cardiomyocytes to diacylglycerol

Yeqing Pi and Jeffery W. Walker

Department of Physiology, University of Wisconsin, Madison, Wisconsin 53706

Diacylglycerol has been hypothesized to mediate the positive inotropic response of myocardium to the alpha -adrenergic agonists angiotensin II and endothelin. The mechanism of action of diacylglycerol was examined here in adult rat ventricular myocytes by releasing dioctanoylglycerol (diC8) intracellularly from a caged compound while monitoring Ca2+ transients and pH with fluorescent indicators. DiC8 caused a three- to fourfold increase in twitch amplitude and a twofold increase in the systolic Ca2+ transient. No other parameter was consistently influenced by diC8, including the kinetics of Ca2+ cycling, the Ca2+ content of the sarcoplasmic reticulum, or the myofilament Ca2+ sensitivity. DiC8 also had no detectable effect on intracellular pH or Na+/H+ antiport activity. Consistent with this finding, the Na+/H+ exchange inhibitor N-ethylisopropyl amiloride was without effect on the positive inotropic response to diC8. The marked enhancement of systolic Ca2+ by diC8 suggests that the process of excitation-contraction coupling is an important and possibly preferred target of diacylglycerol-protein kinase C signaling in myocardium.

excitation-contraction coupling; fluorescent indicators; ventricular cells; sodium/hydrogen antiport


This article has been cited by other articles:


Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
A. F. Leite-Moreira, C. Bras-Silva, C. A. Pedrosa, and A. A. Rocha-Sousa
ET-1 increases distensibility of acutely loaded myocardium: a novel ETA and Na+/H+ exchanger-mediated effect
Am J Physiol Heart Circ Physiol, April 1, 2003; 284(4): H1332 - H1339.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Gastrointest. Liver Physiol.Home page
D. J. Turner, B. J. Segura, R. A. Cowles, W. Zhang, and M. W. Mulholland
Functional overlap of IP3- and cADP-ribose-sensitive calcium stores in guinea pig myenteric neurons
Am J Physiol Gastrointest Liver Physiol, July 1, 2001; 281(1): G208 - G215.
[Abstract] [Full Text] [PDF]

Home page
 Circ. Res.Home page
T. J. Kamp and J. W. Hell
Regulation of Cardiac L-Type Calcium Channels by Protein Kinase A and Protein Kinase C
Circ. Res., December 8, 2000; 87(12): 1095 - 1102.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
Y. Pi and J. W. Walker
Diacylglycerol and fatty acids synergistically increase cardiomyocyte contraction via activation of PKC
Am J Physiol Heart Circ Physiol, July 1, 2000; 279(1): H26 - H34.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
P. Narayan, R. M. Mentzer Jr., and R. D. Lasley
Phosphatase inhibitor cantharidin blocks adenosine A1 receptor anti-adrenergic effect in rat cardiac myocytes
Am J Physiol Heart Circ Physiol, January 1, 2000; 278(1): H1 - H7.
[Abstract] [Full Text] [PDF]


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