title: Ultrastructural study of the effect of bleomycin A2 on the nucleolus and its possibly related cytoplasmic constituents in Novikoff hepatoma cells.
abstract: Treatment of Novikoff hepatoma ascites cells with bleomycin A2, in vivo as well as in vitro, in varying doses produced marked alterations in nucleolar and cytoplasmic ultrastructural organization. A series of changes occur including formation of fibrillar centers, fragmentation of fibrillar nucleolar elements, appearance of microspherules, and the loss of fibrillar elements from these nucleoli. A bleomycin concentration of 10 mug/ml in vitro produced an increased number of fibrillar centers with well-defined nucleolonemas. At a concentration of 50 mug/ml, there was an increase in number and fragmentation of these fibrillar centers and many microspherules were found throughout the nucleolus. Approximately one-fourth of the cells contained cytoplasmic fibrillar bodies and amorphous fibrous tufts around the nuclear envelope. At a bleomycin concentration of 100 mug/ml, the nucleoli contained more granular elements and numerous microspherules. Almost 90% of the cells contained cytoplasmic fibrillar bodies. The effects of bleomycin in vivo (10 mg/kg) closely resemble those found in vitro with concentrations of 50 and 100 mug/ml.
mesh_terms: D000818:Animals; D001761:Bleomycin / Q000494:pharmacology* / Q000627:therapeutic use; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy*; D002466:Cell Nucleolus / Q000187:drug effects*; D003593:Cytoplasm / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D008113:Liver Neoplasms / Q000188:drug therapy*; D008297:Male; D008854:Microscopy, Electron; D009374:Neoplasms, Experimental / Q000188:drug therapy; D051381:Rats
chemical_list: D001761:Bleomycin