Influence of Na+-Independent Cl¯-HCO3¯ Exchange on the Slow Force Response to Myocardial Stretch

Previous work demonstrated that the slow force response (SFR) to stretch is due to the increase in calcium transients (Ca<SUP>2+</SUP>T) produced by an autocrine-paracrine mechanism of locally produced angiotensin II/endothelin activating Na<SUP>+</SUP>-H<SUP>+</SUP&...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Cingolani, Horacio Eugenio, Chiappe de Cingolani, Gladys Ethel, Ennis, Irene Lucía, Morgan, Patricio G., Álvarez, Bernardo Víctor, Casey, Joseph R., Dulce, Raúl Ariel, Pérez, Néstor Gustavo, Camilión de Hurtado, María Cristina
Formato: Articulo
Lenguaje:Inglés
Publicado: 2003
Materias:
Ciencias Médicas
AE3
Myocardial pHi
Myocardial stretch
Na+-Ca2+ exchange
Na+-H+ exchanger
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/84527
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-84527
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Ciencias Médicas
AE3
Myocardial pHi
Myocardial stretch
Na+-Ca2+ exchange
Na+-H+ exchanger
spellingShingle Ciencias Médicas
AE3
Myocardial pHi
Myocardial stretch
Na+-Ca2+ exchange
Na+-H+ exchanger
Cingolani, Horacio Eugenio
Chiappe de Cingolani, Gladys Ethel
Ennis, Irene Lucía
Morgan, Patricio G.
Álvarez, Bernardo Víctor
Casey, Joseph R.
Dulce, Raúl Ariel
Pérez, Néstor Gustavo
Camilión de Hurtado, María Cristina
Influence of Na+-Independent Cl¯-HCO3¯ Exchange on the Slow Force Response to Myocardial Stretch
topic_facet Ciencias Médicas
AE3
Myocardial pHi
Myocardial stretch
Na+-Ca2+ exchange
Na+-H+ exchanger
description Previous work demonstrated that the slow force response (SFR) to stretch is due to the increase in calcium transients (Ca<SUP>2+</SUP>T) produced by an autocrine-paracrine mechanism of locally produced angiotensin II/endothelin activating Na<SUP>+</SUP>-H<SUP>+</SUP> exchange. Although a rise in pH<SUB>i</SUB> is presumed to follow stretch, it was observed only in the absence of extracellular bicarbonate, suggesting pH<SUB>i</SUB> compensation through the Na<SUP>+</SUP>-independent Cl¯-HCO3¯ exchange (AE) mechanism. Because available AE inhibitors do not distinguish between different bicarbonate-dependent mechanisms or even between AE isoforms, we developed a functional inhibitory antibody against both the AE3c and AE3fl isoforms (anti-AE3Loop III) that was used to explore if pH<SUB>i</SUB> would rise in stretched cat papillary muscles superfused with bicarbonate after AE3 inhibition. In addition, the influence of this potential increase in pH<SUB>i</SUB> on the SFR was analyzed. In this study, we present evidence that cancellation of AE3 isoforms activity (either by superfusion with bicarbonate-free buffer or with anti-AE3Loop III) results in pH<SUB>i</SUB> increase after stretch and the magnitude of the SFR was larger than when AE was operative, despite of similar increases in [Na<SUP>+</SUP>]<SUB>i</SUB> and Ca<SUP>2+</SUP>T under both conditions. Inhibition of reverse mode Na<SUP>+</SUP>-Ca<SUP>2+</SUP> exchange reduced the SFR to the half when the AE was inactive and totally suppressed it when AE3 was active. The difference in the SFR magnitude and response to inhibition of reverse mode Na<SUP>+</SUP>-Ca<SUP>2+</SUP> exchange can be ascribed to a pH<SUB>i</SUB>-induced increase in myofilament Ca<SUP>2+</SUP> responsiveness.
format Articulo
Articulo
author Cingolani, Horacio Eugenio
Chiappe de Cingolani, Gladys Ethel
Ennis, Irene Lucía
Morgan, Patricio G.
Álvarez, Bernardo Víctor
Casey, Joseph R.
Dulce, Raúl Ariel
Pérez, Néstor Gustavo
Camilión de Hurtado, María Cristina
author_facet Cingolani, Horacio Eugenio
Chiappe de Cingolani, Gladys Ethel
Ennis, Irene Lucía
Morgan, Patricio G.
Álvarez, Bernardo Víctor
Casey, Joseph R.
Dulce, Raúl Ariel
Pérez, Néstor Gustavo
Camilión de Hurtado, María Cristina
author_sort Cingolani, Horacio Eugenio
title Influence of Na+-Independent Cl¯-HCO3¯ Exchange on the Slow Force Response to Myocardial Stretch
title_short Influence of Na+-Independent Cl¯-HCO3¯ Exchange on the Slow Force Response to Myocardial Stretch
title_full Influence of Na+-Independent Cl¯-HCO3¯ Exchange on the Slow Force Response to Myocardial Stretch
title_fullStr Influence of Na+-Independent Cl¯-HCO3¯ Exchange on the Slow Force Response to Myocardial Stretch
title_full_unstemmed Influence of Na+-Independent Cl¯-HCO3¯ Exchange on the Slow Force Response to Myocardial Stretch
title_sort influence of na+-independent cl¯-hco3¯ exchange on the slow force response to myocardial stretch
publishDate 2003
url http://sedici.unlp.edu.ar/handle/10915/84527
work_keys_str_mv AT cingolanihoracioeugenio influenceofnaindependentclhco3exchangeontheslowforceresponsetomyocardialstretch
AT chiappedecingolanigladysethel influenceofnaindependentclhco3exchangeontheslowforceresponsetomyocardialstretch
AT ennisirenelucia influenceofnaindependentclhco3exchangeontheslowforceresponsetomyocardialstretch
AT morganpatriciog influenceofnaindependentclhco3exchangeontheslowforceresponsetomyocardialstretch
AT alvarezbernardovictor influenceofnaindependentclhco3exchangeontheslowforceresponsetomyocardialstretch
AT caseyjosephr influenceofnaindependentclhco3exchangeontheslowforceresponsetomyocardialstretch
AT dulceraulariel influenceofnaindependentclhco3exchangeontheslowforceresponsetomyocardialstretch
AT pereznestorgustavo influenceofnaindependentclhco3exchangeontheslowforceresponsetomyocardialstretch
AT camiliondehurtadomariacristina influenceofnaindependentclhco3exchangeontheslowforceresponsetomyocardialstretch
bdutipo_str Repositorios
_version_ 1764820488854437889

Ejemplares similares