Reperfusion after Ichemia Causes Cytosolic Calcium Overload Due to Rapid Calcium Release from the Sarcoplasmic Reticulum

After a brief ischemic insult, a sustained contractile dysfunction occurs manifested as a sluggish recovery of pump function (myocardial stunning). Substantial evidence supports that myocardial dysfunction is triggered by Ca2+ overload during reperfusion (R). Previous results from different laborato...

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Autores principales: Valverde, Carlos Alfredo, Kornyeyev, Dmytro, Mattiazzi, Alicia Ramona, Escobar, Ariel L.
Formato: Articulo Comunicacion
Lenguaje:Inglés
Publicado: 2009
Materias:
Medicina
Calcium
Sarcoplasmic Reticulum
Ichemia
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/139279
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-139279
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Medicina
Calcium
Sarcoplasmic Reticulum
Ichemia
spellingShingle Medicina
Calcium
Sarcoplasmic Reticulum
Ichemia
Valverde, Carlos Alfredo
Kornyeyev, Dmytro
Mattiazzi, Alicia Ramona
Escobar, Ariel L.
Reperfusion after Ichemia Causes Cytosolic Calcium Overload Due to Rapid Calcium Release from the Sarcoplasmic Reticulum
topic_facet Medicina
Calcium
Sarcoplasmic Reticulum
Ichemia
description After a brief ischemic insult, a sustained contractile dysfunction occurs manifested as a sluggish recovery of pump function (myocardial stunning). Substantial evidence supports that myocardial dysfunction is triggered by Ca2+ overload during reperfusion (R). Previous results from different laboratories including our own, describe a cascade of events triggered by R that involves the activation of Na+/H+ and Na+/Ca2+ (NCX) exchangers, with enhanced Ca2+ influx. Whether this Ca2+ influx directly produces the increase in cytosolic Ca2+ or this increase occurs as a consequence of sarcoplasmic reticulum (SR) Ca2+ release triggered in turn by the Ca2+ influx, is not known. To address this issue, we performed 12 min of global no-flow ischemia followed by R in the isovolumic Langendorff perfused mouse heart positioned on a Pulsed Local Field Fluorescence microscope and loaded with fluorescent dyes (Rhod-2 or Mag-Fluo-4 to assess cytosolic or SR Ca2+, respectively). The results indicated an initial increase in diastolic Ca2+ during early R that gradually returned to pre-ischemic levels. This increase was associated with a decrease in SR Ca2+ content that recovered within 10 min, as a mirror image of the diastolic Ca2+ profile. Additional experiments in which caffeine pulses (20 mM) were applied, confirmed that SR Ca2+ content was greatly diminished at the onset of R and gradually recovered within 10 min of R. The present findings indicate that the increase in diastolic Ca2+ that occurs upon R is due to a SR Ca2+ release and not just because of the Ca2+ entry through the reverse NCX mode, as has been previously thought.
format Articulo
Comunicacion
author Valverde, Carlos Alfredo
Kornyeyev, Dmytro
Mattiazzi, Alicia Ramona
Escobar, Ariel L.
author_facet Valverde, Carlos Alfredo
Kornyeyev, Dmytro
Mattiazzi, Alicia Ramona
Escobar, Ariel L.
author_sort Valverde, Carlos Alfredo
title Reperfusion after Ichemia Causes Cytosolic Calcium Overload Due to Rapid Calcium Release from the Sarcoplasmic Reticulum
title_short Reperfusion after Ichemia Causes Cytosolic Calcium Overload Due to Rapid Calcium Release from the Sarcoplasmic Reticulum
title_full Reperfusion after Ichemia Causes Cytosolic Calcium Overload Due to Rapid Calcium Release from the Sarcoplasmic Reticulum
title_fullStr Reperfusion after Ichemia Causes Cytosolic Calcium Overload Due to Rapid Calcium Release from the Sarcoplasmic Reticulum
title_full_unstemmed Reperfusion after Ichemia Causes Cytosolic Calcium Overload Due to Rapid Calcium Release from the Sarcoplasmic Reticulum
title_sort reperfusion after ichemia causes cytosolic calcium overload due to rapid calcium release from the sarcoplasmic reticulum
publishDate 2009
url http://sedici.unlp.edu.ar/handle/10915/139279
work_keys_str_mv AT valverdecarlosalfredo reperfusionafterichemiacausescytosoliccalciumoverloadduetorapidcalciumreleasefromthesarcoplasmicreticulum
AT kornyeyevdmytro reperfusionafterichemiacausescytosoliccalciumoverloadduetorapidcalciumreleasefromthesarcoplasmicreticulum
AT mattiazzialiciaramona reperfusionafterichemiacausescytosoliccalciumoverloadduetorapidcalciumreleasefromthesarcoplasmicreticulum
AT escobarariell reperfusionafterichemiacausescytosoliccalciumoverloadduetorapidcalciumreleasefromthesarcoplasmicreticulum
bdutipo_str Repositorios
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