title: Labeled bleomycin as a tumor localizing agent III. Selectivity of tumor tissue uptake of the different forms of [57Co] bleomycin A2 and B2.
abstract: The cell uptake of the different forms (I and II) of [57Co]bleomycin A2 and B2 was studied in a Rhabdomyosarcoma cell culture. The results show that the uptake of form I appears to be significantly higher than the uptake of form II. The evidence presented indicates that form I is formed in vivo as well as in vitro from form II by biotransformation. Transferrin stimulates the uptake of Co-bleomycin B2 form I only. As a result of trypsin treatment, it is suggested that form II binds only on the outer cell membrane and is not able to pass this membrane.
mesh_terms: D000818:Animals; D001711:Biotransformation; D001761:Bleomycin / Q000378:metabolism* / Q000494:pharmacology / Q000031:analogs & derivatives; D001769:Blood; D002478:Cells, Cultured; D003037:Cobalt Radioisotopes; D066298:In Vitro Techniques; D007668:Kidney / Q000378:metabolism; D009374:Neoplasms, Experimental / Q000378:metabolism; D051381:Rats; D012208:Rhabdomyosarcoma / Q000378:metabolism*; D014168:Transferrin / Q000494:pharmacology; D014357:Trypsin
chemical_list: D003037:Cobalt Radioisotopes; D014168:Transferrin; C030187:cobalt bleomycin; D001761:Bleomycin; D014357:Trypsin