title: Action of a cytotoxin from Pseudomonas aeruginosa on human leukemic cell lines. Increase in cell permeability to Ca2+ and Mn2+ and lack of stimulation of inositol lipid turnover.
abstract: Quin2 loaded human leukemic, JURKAT and K562 cells, were exposed to various doses of Pseudomonas aeruginosa cytotoxin. This cytotoxin induced an increase in quin2 fluorescence indicating an increase in the cytoplasmic free Ca2+ concentration. The rate of the fluorescence increase and the lag time before the response were dependent on the doses of the cytotoxin. Addition of MnCl2 to the cytotoxin-treated cells induced a decrease in the quin2 fluorescence at rates dependent on the doses of the cytotoxin. The cytotoxin did not stimulate the inositol lipid turnover in JURKAT cells, which was determined by the accumulation of [3H]inositol phosphates in myo-[2-3H]inositol-prelabeled cells in the presence of LiCl. These results indicate that the cytotoxin increases cell permeability to both Ca2+ and Mn2+ by direct breakdown of the permeability barrier of the plasma membrane.
mesh_terms: D000634:Aminoquinolines; D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D002463:Cell Membrane Permeability / Q000187:drug effects; D006801:Humans; D007295:Inositol Phosphates / Q000378:metabolism*; D007938:Leukemia / Q000378:metabolism*; D007951:Leukemia, Myeloid / Q000378:metabolism; D007956:Leukocidins / Q000494:pharmacology*; D008345:Manganese / Q000378:metabolism*; D010835:Phytohemagglutinins / Q000494:pharmacology; D013050:Spectrometry, Fluorescence; D013403:Sugar Phosphates / Q000378:metabolism*; D013601:T-Lymphocytes
chemical_list: D000634:Aminoquinolines; D007295:Inositol Phosphates; D007956:Leukocidins; D010835:Phytohemagglutinins; D013403:Sugar Phosphates; D008345:Manganese; C035739:Quin2; D002118:Calcium