AJP - Heart Calcium Transients and Cell-Sarcomere
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Heart Circ Physiol 274: H1152-H1162, 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 Gambassi, G.
Right arrow Articles by Capogrossi, M. C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Gambassi, G.
Right arrow Articles by Capogrossi, M. C.
Vol. 274, Issue 4, H1152-H1162, April 1998

Opposing effects of alpha 1-adrenergic receptor subtypes on Ca2+ and pH homeostasis in rat cardiac myocytes

Giovanni Gambassi, Harold A. Spurgeon, Bruce D. Ziman, Edward G. Lakatta, and Maurizio C. Capogrossi

Laboratory of Cardiovascular Science, Gerontology Research Center, National Institute on Aging, National Institutes of Health, Baltimore, Maryland 21224

We examined the effect of alpha 1-adrenergic receptor (AR) subtypes on contraction, cytosolic Ca2+ concentration ([Ca2+]i), and cytosolic pH (pHi) of rat ventricular myocytes loaded with the Ca2+ indicator indo 1 or the pH indicator carboxy-seminaphthorhodafluor-1. Nonselective alpha 1-AR stimulation was effected with phenylephrine plus nadolol. alpha 1-AR subtype stimulation was achieved with alpha 1-AR and chloroethylclonidine (CEC) or with alpha 1-AR and WB-4101. Cells were in bicarbonate buffer with 0.5 mM Ca2+ and were electrically stimulated at 0.5 Hz. Results show that 1) nonselective alpha 1-AR stimulation increased twitch and [Ca2+]i transient amplitudes, myofilament response to Ca2+, and pHi; 2) alpha 1-AR plus CEC increased twitch and [Ca2+]i transient amplitudes and also enhanced myofilament response to Ca2+ via cytosolic alkalinization; 3) alpha 1-AR plus WB-4101 decreased twitch and [Ca2+]i transient amplitudes and also pHi; and 4) cytosolic acidification due to alpha 1-AR plus WB-4101 was abolished by protein kinase C inhibition (staurosporine pretreatment) or downregulation (prolonged exposure to phorbol esters). In summary, the net effects of alpha 1-adrenergic stimulation on contraction, [Ca2+]i, and pHi are due to opposing WB-4101- and CEC-sensitive alpha 1-AR subtype signaling pathways.

alpha -adrenoceptor subtypes; chloroethylclonidine; WB-4101; indo 1; cardiac inotropy; cytosolic pH


This article has been cited by other articles:


Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
G.-Y. Wang, D. T. McCloskey, S. Turcato, P. M. Swigart, P. C. Simpson, and A. J. Baker
Contrasting inotropic responses to {alpha}1-adrenergic receptor stimulation in left versus right ventricular myocardium
Am J Physiol Heart Circ Physiol, October 1, 2006; 291(4): H2013 - H2017.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
J. Bokenes, I. Sjaastad, and O. M. Sejersted
Artifactual contractions triggered by field stimulation of cardiomyocytes
J Appl Physiol, May 1, 2005; 98(5): 1712 - 1719.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
D. E. Montgomery, B. M. Wolska, W. G. Pyle, B. B. Roman, J. C. Dowell, P. M. Buttrick, A. P. Koretsky, P. Del Nido, and R. J. Solaro
alpha -Adrenergic response and myofilament activity in mouse hearts lacking PKC phosphorylation sites on cardiac TnI
Am J Physiol Heart Circ Physiol, June 1, 2002; 282(6): H2397 - H2405.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
B. M. Palmer, M. C. Olsson, J. M. Lynch, L. C. Mace, S. M. Snyder, S. Valent, and R. L. Moore
Chronic run training suppresses alpha -adrenergic response of rat cardiomyocytes and isovolumic left ventricle
Am J Physiol Heart Circ Physiol, December 1, 1999; 277(6): H2136 - H2144.
[Abstract] [Full Text] [PDF]


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