Cytoplasmic changes in cardiac cells during a contraction cycle detected by fluorescence polarization

Dror Fixler, Reuven Tirosh, Asher Shainberg, Motti Deutsch

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


Intracellular structural changes, occurring in a cardiac myocyte during a contraction cycle, were investigated by means of intracellular fluorescein fluorescence polarization (IFFP), in comparison to cytoplasmic concentration of Ca2+ [Ca2+]i measured by indo-1. A simple physical model is presented. It assumes a biphase intracellular matrix, differing in its potency to restrict hosting fluorescent probe mobility. The first is a mobile nonrestricting phase, made mostly of aqua (aqua zone), while the second is a mobile-restricting phase, allocated mainly at the proximity of the filament sites. Their physicochemical properties such as [Ca2+], viscosity, and pH, may differ, thereby influencing the hosting probe fluorescence characteristics differently. These possible influences were examined experimentally. Based on experimental data, the model enables the evaluation, to first order of approximation, of the relative number of fluorescent probes populating the two phases and the time variation viscosity (ηr(t)) of the mobile-restricting filament zones taking place throughout the contraction cycle.

Original languageEnglish
Pages (from-to)89-100
Number of pages12
JournalJournal of Fluorescence
Issue number2
StatePublished - 2001

Bibliographical note

Funding Information:
This work was supported by the Horwitz Foundation Grant.


  • Cardiac myocyte
  • Indo-1
  • Intracellular Ca
  • Ion concentration


Dive into the research topics of 'Cytoplasmic changes in cardiac cells during a contraction cycle detected by fluorescence polarization'. Together they form a unique fingerprint.

Cite this