title: Influence of mitogenic activators on the structure of leukocytes.
abstract: The membrane structures of resting and activated peripheral blood mononuclear cells (leukocytes) were investigated using polarized light spectroscopy. Absorption, fluorescence and delayed luminescence spectra of leukocytes embedded in isotropic and stretched films of polyvinyl alcohol were measured. Polymer films were prepared using H2O and D2O. The perturbations of the membrane by the two mitogenic activators phytohaemagglutinin and phorbol-myristate-13-acetate were compared. Scattergrams taken using a flow cytometry method for both the resting and activated samples did not show leukocyte fragmentation or a change in the cell volume as a result of the first hour of activation. The polarized fluorescence spectra clearly showed a perturbation of the membrane structure by the activators. The absorption spectra were much less affected by activation. The delayed luminescence emission intensity of the leukocytes was low with a decay time of about 5 microseconds. The influence of phorbol-myristate-13-acetate addition on all spectral properties of the leukocytes was greater than that of phytohaemagglutinin at the same activator concentration. Polymer film deuteration influences the spectra, which shows the important role of water in maintaining the natural membrane structure. This influence is different in various regions of the emission spectrum, which shows that the various chromophores have different contacts with the environment.
authors.affiliation: Institute of Physics, Poznań University of Technology, Poland.
authors.forename: D
authors.initials: D
authors.lastname: Frackowiak
authors.forename: M
authors.initials: M
authors.lastname: Niedbalska
authors.forename: K
authors.initials: K
authors.lastname: Wiktorowicz
mesh_terms: D002462:Cell Membrane / Q000187:drug effects; D002478:Cells, Cultured; D017666:Deuterium Oxide; D005454:Fluorescence Polarization; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000187:drug effects*; D008163:Luminescent Measurements; D008934:Mitogens / Q000494:pharmacology*; D010835:Phytohemagglutinins / Q000494:pharmacology*; D012542:Scattering, Radiation; D013050:Spectrometry, Fluorescence; D013053:Spectrophotometry; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
chemical_list: D008934:Mitogens; D010835:Phytohemagglutinins; D017666:Deuterium Oxide; D013755:Tetradecanoylphorbol Acetate