title: Determination of peplomycin in mouse tissues and biofluids by radioimmunoassay.
abstract: Peplomycin, an antitumour antibiotic analogue of bleomycin, was measured in mouse tissues using a rapid radioimmunoassay. Antiserum, obtained by immunizing rabbits with peplomycin-bovine serum albumin conjugate, showed no significant cross-reactivity with the closely related peplomycin analogues bleomycin and liblomycin, nor with a number of other structurally unrelated antitumour drugs. The assay is sensitive and can detect peplomycin levels as low as 2 ng ml-1. The relative intra- and inter-assay standard deviation is < or = 5%, indicating good assay reproducibility. Peplomycin levels in mouse tissues were easily determined without extraction. Fifteen minutes after administration of a single intraperitoneal dose of peplomycin at 8.5 mg kg-1 (1/10 of LD50), high drug levels were found in plasma (46 micrograms ml-1), kidneys (38 micrograms g-1), urine and bladder (32 micrograms ml-1), followed by gastrointestinal tract (13 micrograms g-1), lung (8 micrograms g-1), spleen (3.7 micrograms g-1), heart (3.6 micrograms g-1), gall bladder (2.7 micrograms g-1), liver (2 micrograms g-1), and brain (0.6 microgram g-1). The total amount of drug in all these organs accounted for more than 80% of the dose administered. We conclude that the radioimmunoassay is sensitive and reproducible and is an ideal tool for measuring peplomycin in tissues and biofluids for pharmacological studies.
authors.affiliation: Department of Medical Oncology, University of Texas M.D. Anderson Cancer Center, Houston 77030.
authors.forename: J R
authors.initials: JR
authors.lastname: Lin
authors.forename: N S
authors.initials: NS
authors.lastname: Brown
authors.forename: R A
authors.initials: RA
authors.lastname: Newman
authors.forename: D H
authors.initials: DH
authors.lastname: Ho
mesh_terms: D000818:Animals; D007114:Immunization; D007274:Injections, Intraperitoneal; D051379:Mice; D017663:Peplomycin / Q000008:administration & dosage / Q000032:analysis* / Q000097:blood / Q000652:urine; D011863:Radioimmunoassay / Q000379:methods; D013696:Temperature; D014018:Tissue Distribution
chemical_list: D017663:Peplomycin