Accession Number : ADA021834


Title :   The Chemical and Biological Properties of Isolated Radiolabeled Bleomycin Components,


Corporate Author : ARMED FORCES RADIOBIOLOGY RESEARCH INST BETHESDA MD


Personal Author(s) : Eckelman,W. C. ; Rzeszotarski,W. J. ; Siegel,B. A. ; Kubota,H. ; Chelliah,M.


Report Date : DEC 1975


Pagination or Media Count : 15


Abstract : Cobalt-57 bleomycin is a diagnostically useful radiopharmaceutical but little is known about the nature of its individual fractions in regard to their metal binding capacity and their in vivo distribution. Bleomycin was separated by high-performance liquid chromatography (HPLC) into four major components. These components were labeled and the distribution studied in tumor-bearing rats at 2 and 24 hours. In vivo radiochemical purity was also determined. Of the nine HPLC systems studied, Porasil A eluted with a 0.3 percent ammonium formate-methanol mobile phase gave the best separation of the fractions. These fractions were copper-free and retained their biological activity and purity. An in vitro competitive binding study of 57Co bleomycin with either 57Co HSA or 57Co EDTA showed the labeled bleomycin to be a strong chelate. The biological distribution in tumor-bearing rats showed significantly higher concentration in tumors at 2 hours for fractions A2 and B2 as compared to the bleomycin mixture. The other fractions, A1 and demethyl-A2, had lower tumor concentrations than the bleomycin mixture.


Descriptors :   *LABELED SUBSTANCES, *ANTIBIOTICS, *DIAGNOSTIC AGENTS, EXPERIMENTAL DATA, RATS, NEOPLASMS, DIAGNOSIS(MEDICINE), TABLES(DATA), DRUGS, IN VIVO ANALYSIS, CHEMICAL ANALYSIS, PHARMACOLOGY, CHROMATOGRAPHY, COBALT COMPOUNDS, LABORATORY ANIMALS, CHELATE COMPOUNDS.


Subject Categories : PHARMACOLOGY


Distribution Statement : APPROVED FOR PUBLIC RELEASE