Optical mapping of intra-sarcoplasmic reticulum Ca<sup>2+</sup> and transmembrane potential in the Langendorff-perfused rabbit heart

Lianguo Wang, Nicole M. De Jesus, Crystal M Ripplinger

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6 Scopus citations

Abstract

Sarcoplasmic reticulum (SR) Ca<sup>2+</sup> handling plays a key role in normal excitation-contraction coupling and aberrant SR Ca<sup>2+</sup> handling is known to play a significant role in certain types of arrhythmia. Because arrhythmias are spatially distinct, emergent phenomena, they must be investigated at the tissue level. However, methods for directly probing SR Ca<sup>2+</sup> in the intact heart remain limited. This article describes the protocol for dual optical mapping of transmembrane potential (V<inf>m</inf>) and free intra-SR [Ca<sup>2+</sup>] ([Ca2+]<inf>SR</inf>) in the Langendorff-perfused rabbit heart. This approach takes advantage of the low-affinity Ca<sup>2+</sup> indicator Fluo-5N, which has minimal fluorescence in the cytosol where intracellular [Ca<sup>2+</sup>] ([Ca<sup>2+</sup>]<inf>i</inf>)<inf>2+</inf> is relatively low but exhibits significant fluorescence in the SR lumen where [Ca<sup>2+</sup>]<inf>SR</inf> is in the millimolar range. In addition to revealing SR Ca<sup>2+</sup> characteristics spatially across the epicardial surface of the heart, this approach has the distinct advantage of simultaneous monitoring of V<inf>m</inf>, allowing for investigations into the bidirectional relationship between V<inf>m</inf> and SR Ca<sup>2+</sup> and the role of SR Ca<sup>2+</sup> in arrhythmogenic phenomena.

Original languageEnglish (US)
Article numbere53166
JournalJournal of Visualized Experiments
Volume2015
Issue number103
DOIs
StatePublished - Sep 10 2015

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Keywords

  • Arrhythmia
  • Calcium
  • Calcium-sensitive dye
  • Cardiac electrophysiology
  • Excitation-contraction coupling
  • Issue 103
  • Molecular biology
  • Optical mapping
  • Rabbit
  • Sarcoplasmic reticulum
  • Voltage-sensitive dye

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Chemical Engineering(all)
  • Immunology and Microbiology(all)
  • Neuroscience(all)

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