Reverse mode of the Na+-Ca2+ exchange after myocardial stretch : Underlying mechanism of the slow force response

This study was designed to gain additional insight into the mechanism of the slow force response (SFR) to stretch of cardiac muscle. SFR and changes in intracellular Na<SUP>+</SUP> concentration ([Na<SUP>+</SUP>]<SUB>i</SUB>) were assessed in cat papillary muscles...

Descripción completa

Detalles Bibliográficos
Autores principales: Pérez, Néstor Gustavo, Camilión de Hurtado, María Cristina, Cingolani, Horacio Eugenio
Formato: Articulo
Lenguaje:Inglés
Publicado: 2001
Materias:
Ciencias Médicas
Angiotensin II
Endothelin
Myocardial stretch
Na+-Ca2+ exchange
Na+-H+ exchange
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/84943
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-84943
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
Angiotensin II
Endothelin
Myocardial stretch
Na+-Ca2+ exchange
Na+-H+ exchange
spellingShingle Ciencias Médicas
Angiotensin II
Endothelin
Myocardial stretch
Na+-Ca2+ exchange
Na+-H+ exchange
Pérez, Néstor Gustavo
Camilión de Hurtado, María Cristina
Cingolani, Horacio Eugenio
Reverse mode of the Na+-Ca2+ exchange after myocardial stretch : Underlying mechanism of the slow force response
topic_facet Ciencias Médicas
Angiotensin II
Endothelin
Myocardial stretch
Na+-Ca2+ exchange
Na+-H+ exchange
description This study was designed to gain additional insight into the mechanism of the slow force response (SFR) to stretch of cardiac muscle. SFR and changes in intracellular Na<SUP>+</SUP> concentration ([Na<SUP>+</SUP>]<SUB>i</SUB>) were assessed in cat papillary muscles stretched from 92% to ≈98% of L<SUB>max</SUB>. The SFR was 120±0.6% (n=5) of the rapid initial phase and coincided with an increase in [Na<SUP>+</SUP>]<SUB>i</SUB>. The SFR was markedly depressed by Na<SUP>+</SUP>-H<SUP>+</SUP> exchanger inhibition, AT1 receptor blockade, nonselective endothelin-receptor blockade and selective ETA-receptor blockade, extracellular Na<SUP>+</SUP> removal and inhibition of the reverse mode of the Na<SUP>+</SUP>-Ca<SUP>2+</SUP> exchange by KB-R7943. KB-R7943 prevented the SFR but not the increase in [Na<SUP>+</SUP>]<SUB>i</SUB>. Inhibition of endothelin-converting enzyme activity by phosphoramidon suppressed both the SFR and the increase in [Na<SUP>+</SUP>]<SUB>i</SUB>. The SFR and the increase in [Na<SUP>+</SUP>]<SUB>i</SUB> after stretch were both present in muscles with their endothelium (vascular and endocardial) made functionally inactive by Triton X-100. In these muscles, phosphoramidon also suppressed the SFR and the increase in [Na<SUP>+</SUP>]<SUB>i</SUB>. The data provide evidence that the last step of the autocrine-paracrine mechanism leading to the SFR to stretch is Ca<SUP>2+</SUP> entry through the reverse mode of Na<SUP>+</SUP>-Ca<SUP>2+</SUP> exchange.
format Articulo
Articulo
author Pérez, Néstor Gustavo
Camilión de Hurtado, María Cristina
Cingolani, Horacio Eugenio
author_facet Pérez, Néstor Gustavo
Camilión de Hurtado, María Cristina
Cingolani, Horacio Eugenio
author_sort Pérez, Néstor Gustavo
title Reverse mode of the Na+-Ca2+ exchange after myocardial stretch : Underlying mechanism of the slow force response
title_short Reverse mode of the Na+-Ca2+ exchange after myocardial stretch : Underlying mechanism of the slow force response
title_full Reverse mode of the Na+-Ca2+ exchange after myocardial stretch : Underlying mechanism of the slow force response
title_fullStr Reverse mode of the Na+-Ca2+ exchange after myocardial stretch : Underlying mechanism of the slow force response
title_full_unstemmed Reverse mode of the Na+-Ca2+ exchange after myocardial stretch : Underlying mechanism of the slow force response
title_sort reverse mode of the na+-ca2+ exchange after myocardial stretch : underlying mechanism of the slow force response
publishDate 2001
url http://sedici.unlp.edu.ar/handle/10915/84943
work_keys_str_mv AT pereznestorgustavo reversemodeofthenaca2exchangeaftermyocardialstretchunderlyingmechanismoftheslowforceresponse
AT camiliondehurtadomariacristina reversemodeofthenaca2exchangeaftermyocardialstretchunderlyingmechanismoftheslowforceresponse
AT cingolanihoracioeugenio reversemodeofthenaca2exchangeaftermyocardialstretchunderlyingmechanismoftheslowforceresponse
bdutipo_str Repositorios
_version_ 1764820488748531714

Ejemplares similares