Transient Ca2+ depletion of the sarcoplasmic reticulum at the onset of reperfusion
Aims: Myocardial stunning is a contractile dysfunction that occurs after a brief ischaemic insult. Substantial evidence supports that this dysfunction is triggered by Ca2+ overload during reperfusion. The aim of the present manuscript is to define the origin of this Ca2+ increase in the intact heart...
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| Autores principales: | , , , , , |
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| Formato: | Articulo |
| Lenguaje: | Inglés |
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2010
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| Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/82441 |
| Aporte de: |
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I19-R120-10915-82441 |
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dspace |
| institution |
Universidad Nacional de La Plata |
| institution_str |
I-19 |
| repository_str |
R-120 |
| collection |
SEDICI (UNLP) |
| language |
Inglés |
| topic |
Ciencias Médicas Calcium Fluorescence Ischaemia/reperfusion Sarcoplasmic reticulum |
| spellingShingle |
Ciencias Médicas Calcium Fluorescence Ischaemia/reperfusion Sarcoplasmic reticulum Valverde, Carlos Alfredo Kornyeyev, Dmytro Ferreiro, Marcela Petrosky, Azadé D. Mattiazzi, Alicia Ramona Escobar, Ariel L. Transient Ca2+ depletion of the sarcoplasmic reticulum at the onset of reperfusion |
| topic_facet |
Ciencias Médicas Calcium Fluorescence Ischaemia/reperfusion Sarcoplasmic reticulum |
| description |
Aims: Myocardial stunning is a contractile dysfunction that occurs after a brief ischaemic insult. Substantial evidence supports that this dysfunction is triggered by Ca2+ overload during reperfusion. The aim of the present manuscript is to define the origin of this Ca2+ increase in the intact heart. Methods and results: To address this issue, Langendorff-perfused mouse hearts positioned on a pulsed local field fluorescence microscope and loaded with fluorescent dyes Rhod-2, Mag-fluo-4, and Di-8-ANEPPS, to assess cytosolic Ca2+, sarcoplasmic reticulum (SR) Ca2+, and transmembrane action potentials (AP), respectively, in the epicardial layer of the hearts, were submitted to 12 min of global ischaemia followed by reperfusion. Ischaemia increased cytosolic Ca2+ in association with a decrease in intracellular Ca2+ transients and a depression of Ca2+ transient kinetics, i.e. the rise time and decay time constant of Ca2+ transients were significantly prolonged. Reperfusion produced a transient increase in cytosolic Ca2+ (Ca2+ bump), which was temporally associated with a decrease in SR-Ca2+ content, as a mirror-like image. Caffeine pulses (20 mM) confirmed that SR-Ca2+ content was greatly diminished at the onset of reflow. The SR-Ca2+ decrease was associated with a decrease in Ca2+ transient amplitude and a shortening of AP duration mainly due to a decrease in phase 2. Conclusion: To the best of our knowledge, this is the first study in which SR-Ca2+ transients are recorded in the intact heart, revealing a previously unknown participation of SR on cytosolic Ca2+ overload upon reperfusion in the intact beating heart. Additionally, the associated shortening of phase 2 of the AP may provide a clue to explain early reperfusion arrhythmias. |
| format |
Articulo Articulo |
| author |
Valverde, Carlos Alfredo Kornyeyev, Dmytro Ferreiro, Marcela Petrosky, Azadé D. Mattiazzi, Alicia Ramona Escobar, Ariel L. |
| author_facet |
Valverde, Carlos Alfredo Kornyeyev, Dmytro Ferreiro, Marcela Petrosky, Azadé D. Mattiazzi, Alicia Ramona Escobar, Ariel L. |
| author_sort |
Valverde, Carlos Alfredo |
| title |
Transient Ca2+ depletion of the sarcoplasmic reticulum at the onset of reperfusion |
| title_short |
Transient Ca2+ depletion of the sarcoplasmic reticulum at the onset of reperfusion |
| title_full |
Transient Ca2+ depletion of the sarcoplasmic reticulum at the onset of reperfusion |
| title_fullStr |
Transient Ca2+ depletion of the sarcoplasmic reticulum at the onset of reperfusion |
| title_full_unstemmed |
Transient Ca2+ depletion of the sarcoplasmic reticulum at the onset of reperfusion |
| title_sort |
transient ca2+ depletion of the sarcoplasmic reticulum at the onset of reperfusion |
| publishDate |
2010 |
| url |
http://sedici.unlp.edu.ar/handle/10915/82441 |
| work_keys_str_mv |
AT valverdecarlosalfredo transientca2depletionofthesarcoplasmicreticulumattheonsetofreperfusion AT kornyeyevdmytro transientca2depletionofthesarcoplasmicreticulumattheonsetofreperfusion AT ferreiromarcela transientca2depletionofthesarcoplasmicreticulumattheonsetofreperfusion AT petroskyazaded transientca2depletionofthesarcoplasmicreticulumattheonsetofreperfusion AT mattiazzialiciaramona transientca2depletionofthesarcoplasmicreticulumattheonsetofreperfusion AT escobarariell transientca2depletionofthesarcoplasmicreticulumattheonsetofreperfusion |
| bdutipo_str |
Repositorios |
| _version_ |
1764820488284012546 |