Document Detail


Protein kinase inhibitors reduce SR Ca transport in permeabilized cardiac myocytes.
MedLine Citation:
PMID:  8067437     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Phosphorylation of the sarcoplasmic reticulum (SR) protein phospholamban by adenosine 3',5'-cyclic monophosphate (cAMP)-dependent protein kinase (PKA) and Ca-calmodulin-dependent protein kinase (CaM-KII) stimulates Ca-adenosinetriphosphatase (ATPase) activity and SR Ca transport, but the role of CaM-KII-dependent phosphorylation is not well defined. We studied the PKA- and CaM-KII-dependent regulation of SR Ca transport in digitonin-permeabilized rabbit ventricular myocytes. SR Ca uptake and free Ca concentration were measured on line with indo 1 and Ca electrodes in the presence of 20 microM ruthenium red and 10 mM oxalate. neither N5,2'-w-dibutyryl-cAMP (up to 500 microM) nor the nonhydrolyzable cAMP agonist adenosine 3'5'-cyclic monophosphorothioate sodium salt (Sp-cAMP[S]; up to 275 microM) affected the maximum uptake rate (Vmax) or the dissociation constant (Kd) for Ca uptake. However, the PKA inhibitor H-89 significantly increased Kd (e.g., from 307 +/- 67 to 826 +/- 62 nM Ca at 40-65 microM H-89) without significantly affecting Vmax. Both CaM-KII inhibitors, KN-62 (60 microM) and a CaM-KII inhibitory peptide (10 microM), significantly decreased Vmax from 11.95 +/- 0.5 to 9.48 +/- 0.6 nmol.mg-1.min-1 and from 10.95 +/- 1.72 to 7.37 +/- 0.94 nmol.mg-1.min-1, respectively, without consistently changing Kd. The effects of H-89 on Kd and of KN-62 on Vmax were prevented by a monoclonal antibody to phospholamban 2D12 (consistent with the antibody removing the inhibitory effect of phospholamban on the SR Ca-ATPase).(ABSTRACT TRUNCATED AT 250 WORDS)
Authors:
A Mattiazzi; L Hove-Madsen; D M Bers
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  The American journal of physiology     Volume:  267     ISSN:  0002-9513     ISO Abbreviation:  Am. J. Physiol.     Publication Date:  1994 Aug 
Date Detail:
Created Date:  1994-09-21     Completed Date:  1994-09-21     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  0370511     Medline TA:  Am J Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  H812-20     Citation Subset:  IM    
Affiliation:
Department of Physiology, Loyola University Medical School, Maywood, Illinois 60153.
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MeSH Terms
Descriptor/Qualifier:
1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine* / analogs & derivatives*
Animals
Antibodies, Monoclonal / immunology
Biological Transport
Calcium / metabolism*
Calcium-Binding Proteins / immunology
Calcium-Calmodulin-Dependent Protein Kinases / antagonists & inhibitors
Cell Membrane Permeability
Cyclic AMP-Dependent Protein Kinases / metabolism
Enzyme Activation
Isoquinolines / antagonists & inhibitors
Myocardium / cytology,  metabolism*
Piperazines / antagonists & inhibitors
Protein Kinase Inhibitors*
Rabbits
Sarcoplasmic Reticulum / metabolism*
Sulfonamides*
Grant Support
ID/Acronym/Agency:
HL-30077/HL/NHLBI NIH HHS
Chemical
Reg. No./Substance:
0/Antibodies, Monoclonal; 0/Calcium-Binding Proteins; 0/Isoquinolines; 0/Piperazines; 0/Protein Kinase Inhibitors; 0/Sulfonamides; 0/phospholamban; 127191-97-3/KN 62; 127243-85-0/H 89; 7440-70-2/Calcium; 84477-87-2/1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; EC 2.7.11.11/Cyclic AMP-Dependent Protein Kinases; EC 2.7.11.17/Calcium-Calmodulin-Dependent Protein Kinases

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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