TY  - JOUR
A1  - Roder, Phillip
A1  - Hille, Carsten
ED  - Hille, Carsten
T1  - ANG-2 for quantitative Na+ determination in living cells by time-resolved fluorescence microscopy
JF  - Photochemical & Photobiological Sciences
N2  - Sodium ions (Na+) play an important role in a plethora of cellular processes, which are complex and partly still unexplored. For the investigation of these processes and quantification of intracellular Na+ concentrations ([Na+]i), two-photon coupled fluorescence lifetime imaging microscopy (2P-FLIM) was performed in the salivary glands of the cockroach Periplaneta americana. For this, the novel Na+-sensitive fluorescent dye Asante NaTRIUM Green-2 (ANG-2) was evaluated, both in vitro and in situ. In this context, absorption coefficients, fluorescence quantum yields and 2P action cross-sections were determined for the first time. ANG-2 was 2P-excitable over a broad spectral range and displayed fluorescence in the visible spectral range. Although the fluorescence decay behaviour of ANG-2 was triexponential in vitro, its analysis indicates a Na+-sensitivity appropriate for recordings in living cells. The Na+-sensitivity was reduced in situ, but the biexponential fluorescence decay behaviour could be successfully analysed in terms of quantitative [Na+]i recordings. Thus, physiological 2P-FLIM measurements revealed a dopamine-induced [Na+]i rise in cockroach salivary gland cells, which was dependent on a Na+-K+-2Cl− cotransporter (NKCC) activity. It was concluded that ANG-2 is a promising new sodium indicator applicable for diverse biological systems.
KW  - cockroach salivary-glands
KW  - intracellular na+
KW  - sodium green
KW  - periplaneta-americana
KW  - ventricular myocytes
KW  - lifetime microscopy
KW  - cytosolic sodium
KW  - acinar-cells
KW  - hela-cells
KW  - rat
Y1  - 2014
SN  - 1474-905X
VL  - 12
IS  - 13
SP  - 1699
EP  - 1710
PB  - The Royal Society of Chemistry
CY  - Cambridge
ER  -