title: Bleomycin increases superoxide production in the most active alveolar macrophage subpopulation.
abstract: Pig alveolar macrophages were separated into three subpopulations by density centrifugation. The most dense subpopulation of macrophages had the greatest rate of superoxide anion production of 4.4 +/- 2.6 nmol/1 x 10(6) cells/min. Bleomycin had its greatest effect on this subpopulation by increasing the rate by nearly 100% in cells stimulated with phorbol myristate acetate or phorbol dibutyrate. Bleomycin increased the maximum rate of superoxide production without changing the apparent Km of 0.012 microgram/ml. Bleomycin did not quantitatively effect phorbol dibutyrate binding to alveolar macrophages. The cells have 9.1 +/- 1.0 x 10(5) sites/cell with a KD of 16 nmol. Results indicate that bleomycin may enhance superoxide production by effecting steps distal to protein kinase C in the superoxide anion production pathway.
mesh_terms: D000818:Animals; D001761:Bleomycin / Q000494:pharmacology*; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D002499:Centrifugation, Density Gradient; D004306:Dose-Response Relationship, Immunologic; D008264:Macrophages / Q000166:cytology / Q000378:metabolism*; D010704:Phorbols / Q000493:pharmacokinetics / Q000494:pharmacology; D013481:Superoxides / Q000096:biosynthesis*; D013552:Swine
chemical_list: D010704:Phorbols; D001761:Bleomycin; D013481:Superoxides