ISSN:
1573-4994
Keywords:
1,6-Diphenyl-1,3,5-hexatriene (DPH)
;
living cells
;
phosphatidylcholine
;
phase fluorometry
;
steady-state fluorescence
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract The potential interest of DPH-PC was checked with a macrophagic cell line (P388D1). The uptake of DPH-PC was associated with a rapid increase in both fluorescence intensity and a slow decrease in anisotropy values. A flow cytometry comparative study with DPH revealed in both cases the existence of two cell subpopulations with different labeling levels. The analysis of fluorescence decay of DPH-PC showed two components. The fractional intensity of the main component (9.7 ns) is higher than 92%. The Lorentzian distribution of the main lifetime presents an important homogeneity. The observation that an increase in temperature induced a decrease in steady state anisotropy values but did not affect the lifetime suggests that the anisotropy variations effectively reflect modifications in the cohesion of probe micro-surroundings. A transmembrane diffusional phenomenon of a fraction of fluorescent phospholipids (205) was suggested by a study with a nonpermeant membrane quencher. The transmembrane diffusion was confirmed by extraction of the phospholipid analog with fatty acid free BSA. The use of inhibitors of endogenous phospholipase A2 showed a progressive hydrolysis of the fluorescent phospholipid. Nevertheless, the hydrolysis can be neglected in the case of short term interactions with cells (〈30 min). Therefore, it can be assumed that DPH-PC can be used as a membrane probe.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00865273
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