title: Correlation between the presence of intracellular OK-432 and antitumor activity of peritoneal macrophages.
abstract: The mechanism of the generation of tumoricidal macrophages by intraperitoneal administration of OK-432 was investigated. An association between the presence of intracellular FITC-conjugated OK-432 and the increase of macrophage cytostatic activity was observed after i.p. administration of OK-432. When peritoneal exudate cells were fractionated on the basis of cell size by velocity sedimentation, a higher proportion of macrophages and a strong cytostatic activity were shown in the large cell fractions. Furthermore, in these fractions, increased numbers of macrophages with intracellular FITC conjugated and 3H-acetate labelled OK-432 were observed. Thus, the more cytocidal macrophages can be identified by the presence of intracellular microorganisms. A role for OK-432 in the direct activation of macrophages is suggested.
mesh_terms: D000818:Animals; D001688:Biological Products / Q000494:pharmacology*; D002460:Cell Line; D003602:Cytotoxicity, Immunologic / Q000187:drug effects*; D008264:Macrophages / Q000187:drug effects / Q000276:immunology*; D008325:Mammary Neoplasms, Experimental / Q000276:immunology; D051379:Mice; D008809:Mice, Inbred C3H; D010844:Picibanil / Q000494:pharmacology*
chemical_list: D001688:Biological Products; D010844:Picibanil