Role of phosphorylation of Thr17 residue of phospholamban in mechanical recovery during hypercapnic acidosis
Objectives: To assess the time course of phosphorylation of phospholamban residues, the underlying mechanisms determining these phosphorylations, and their functional impact on the mechanical recovery during acidosis. Methods: Langendorff perfused rat hearts were submitted to 30 min of hypercapnic...
Autores principales: | , , , , , |
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Formato: | Articulo |
Lenguaje: | Inglés |
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2005
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Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/84354 |
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I19-R120-10915-84354 |
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institution |
Universidad Nacional de La Plata |
institution_str |
I-19 |
repository_str |
R-120 |
collection |
SEDICI (UNLP) |
language |
Inglés |
topic |
Ciencias Médicas CaMKII Contractile function Myocardial acidosis Na+/Ca2+ exchanger Phospholamban phosphorylation |
spellingShingle |
Ciencias Médicas CaMKII Contractile function Myocardial acidosis Na+/Ca2+ exchanger Phospholamban phosphorylation Mundiña-Weilenmann, Cecilia Ferrero, Paola Viviana Said, María Matilde Vittone, Leticia Kranias, Evangelia G. Mattiazzi, Alicia Ramona Role of phosphorylation of Thr17 residue of phospholamban in mechanical recovery during hypercapnic acidosis |
topic_facet |
Ciencias Médicas CaMKII Contractile function Myocardial acidosis Na+/Ca2+ exchanger Phospholamban phosphorylation |
description |
Objectives: To assess the time course of phosphorylation of phospholamban residues, the underlying mechanisms determining these phosphorylations, and their functional impact on the mechanical recovery during acidosis.
Methods: Langendorff perfused rat hearts were submitted to 30 min of hypercapnic acidosis. Contractility, relaxation, and phosphorylation of phospholamban residues, immunodetected by specific antibodies, were determined.
Results: Acidosis produced a mechanical impairment followed by a spontaneous recovery, most of which occurred within the first 3 min of acidosis (early recovery). During this period, contractility and relaxation recovered by 67±9% and 77±11%, respectively, from its maximal depression, together with an increase in the Ca<SUP>2+</SUP>-calmodulin-dependent protein kinase II (CaMKII)-dependent phosphorylation of Thr<SUP>17</SUP>. The CaMKII inhibitor KN-93, at 1, 5 and 10 μM, decreased Thr<SUP>17</SUP> phosphorylation to basal levels and produced a similar impairment of the early relaxation recovery (50%). However, only 5 and 10 μM KN-93 inhibited the early contractile recovery and completely blunted the late mechanical recovery. Inhibition of the reverse mode of the Na<SUP>+</SUP>/Ca<SUP>2+</SUP> exchanger by KB-R7943 decreased Thr<SUP>17</SUP> phosphorylation but accelerated the early contractile recovery. Conclusions: CaMKII-dependent Thr<SUP>17</SUP> phosphorylation significantly increased at the beginning of acidosis, is responsible for 50% of the early relaxation recovery, and is linked to the activation of the reverse Na<SUP>+</SUP>/Ca<SUP>2+</SUP> mode. The early contractile recovery and the late mechanical recovery are dependent on CaMKII but independent of the phosphorylation of the Thr<SUP>17</SUP> residue of phospholamban. The reverse Na<SUP>+</SUP>/Ca<SUP>2+</SUP> mode has an additional negative effect that opposes the early mechanical recovery. |
format |
Articulo Articulo |
author |
Mundiña-Weilenmann, Cecilia Ferrero, Paola Viviana Said, María Matilde Vittone, Leticia Kranias, Evangelia G. Mattiazzi, Alicia Ramona |
author_facet |
Mundiña-Weilenmann, Cecilia Ferrero, Paola Viviana Said, María Matilde Vittone, Leticia Kranias, Evangelia G. Mattiazzi, Alicia Ramona |
author_sort |
Mundiña-Weilenmann, Cecilia |
title |
Role of phosphorylation of Thr17 residue of phospholamban in mechanical recovery during hypercapnic acidosis |
title_short |
Role of phosphorylation of Thr17 residue of phospholamban in mechanical recovery during hypercapnic acidosis |
title_full |
Role of phosphorylation of Thr17 residue of phospholamban in mechanical recovery during hypercapnic acidosis |
title_fullStr |
Role of phosphorylation of Thr17 residue of phospholamban in mechanical recovery during hypercapnic acidosis |
title_full_unstemmed |
Role of phosphorylation of Thr17 residue of phospholamban in mechanical recovery during hypercapnic acidosis |
title_sort |
role of phosphorylation of thr17 residue of phospholamban in mechanical recovery during hypercapnic acidosis |
publishDate |
2005 |
url |
http://sedici.unlp.edu.ar/handle/10915/84354 |
work_keys_str_mv |
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bdutipo_str |
Repositorios |
_version_ |
1764820488631091202 |