TY - JOUR
T1 - Cytoplasmic changes in cardiac cells during a contraction cycle detected by fluorescence polarization
AU - Fixler, Dror
AU - Tirosh, Reuven
AU - Shainberg, Asher
AU - Deutsch, Motti
N1 - Funding Information:
This work was supported by the Horwitz Foundation Grant.
PY - 2001
Y1 - 2001
N2 - 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.
AB - 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.
KW - Cardiac myocyte
KW - Indo-1
KW - Intracellular Ca
KW - Ion concentration
UR - http://www.scopus.com/inward/record.url?scp=10844267974&partnerID=8YFLogxK
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AN - SCOPUS:10844267974
SN - 1053-0509
VL - 11
SP - 89
EP - 100
JO - Journal of Fluorescence
JF - Journal of Fluorescence
IS - 2
ER -