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FLOW CYTOMETRIC ANALYSIS OF THE CELLULAR TOXICITY TRIBUTYLTIN
Citation:
Zucker, R., K. Elstein, R. Easterling, AND E. Massaro. FLOW CYTOMETRIC ANALYSIS OF THE CELLULAR TOXICITY TRIBUTYLTIN. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/D-90/043 (NTIS PB90220773), 1990.
Description:
Flow cytometric and light/fluorescence microscopic analyses indicate that tributyltin (TBT) alters the plasma membrane/cytoplasm complex of the murine erythroleukemic cell (MELC) in a dose dependent and time-dependent manner. he flow cytometric parameter axial light loss, a measure of cell volume, decreases in cells exposed to 5 uM TBT relative to control cells or cells exposed to 50 uM TBT. he flow cytometric parameter 90o light scatter, a function of refractive index and a measure of protein content increases as a function of TBT concentration above 0.5 uM, but less than 50 uM DNA distribution across the cell cycle cannot be resolved adequately by flow cytometry. lso, the cells become resistant to solubilization of the cell membrane/cytoplasm complex by nonionic detergents. elative to logarithmical growing cells, MELC in the stationary phase of the growth cycle and butyric acid-differentiated cells exhibit decreased plasma membrane permeability resulting in increased carboxyfluorescein (CF) retention derived from the intracellular hydrolysis of carboxyfluorescein diacetate (CFDA). imilarly, cells exposed to TBT concentrations below 50 uM exhibit increased cellular CF retention. Viability in terms of CFDA hydrolysis/CF retention and propidium iodide (PI) exclusion is not decreased by exposure to TBT concentrations below 1 uM. t doses between 5 and 50 uM, however, cells exhibit both CF and PI fluorescence simultaneously and are programmed for death. t TBT concentrations greater than 1.0 uM, MELC plasma membrane potential, measured with the cyanine dye, 3,3'-dihexyloxacarbocyanine iodide (DiOC6) decreases at the same time that the uptake of PI is observed. n conjunction with other data, the concentration-dependent increase in CF fluorescence, resistance to detergent-mediated solubilization of the plasma membrane/cytoplasm complex, and increase in 90o light scatter suggest fixation (protein denaturation, cross-linking, etc.) as a mechanism of the toxic action of TBT.
