title: Development of a radioimmunoassay procedure for 4-acetamidobiphenyl, a metabolite of the chemical carcinogen 4-aminobiphenyl, in urine.
abstract: The synthetic chemical 4-aminobiphenyl (4-ABP) has been shown to be a bladder carcinogen in both man and animals. A valid radioimmunoassay for a metabolite of 4-ABP has been developed as a means to monitor potential human exposure to 4-ABP. The antibody was produced by the immunization of two female New Zealand White rabbits and was found to be highly specific for 4-acetamidobiphenyl (4-AABP), the acetylated metabolite of 4-ABP. At an initial dilution of 1/5000, the antisera bound 45% of the [125I]-labeled derivative of 4-ABP. This derivative was prepared by coupling 4-hemisuccinamidobiphenyl (4-HSBP) with tyramine, and then radioiodinating this compound using the enzymatic lactoperoxidase method. The dose of 4-acetamidobiphenyl which would displace 50% of the labeled hapten initially bound to the antiserum, was about 1 ng (4.8 pmol). Scatchard analysis of the standard curve binding data indicated the presence of at least two populations of binding sites. The equilibrium association constant for the higher binding affinity component was 2.8 x 10(8) Liters/mole. A series of 210 randomly selected human urine control samples were analyzed and a nonspecific background contribution of 1.67 +/- 0.07 ng (mean + S.E.) of "4-acetamidobiphenyl"/mL urine was found.
mesh_terms: D000611:Aminobiphenyl Compounds / Q000652:urine*; D000818:Animals; D002273:Carcinogens / Q000378:metabolism*; D005260:Female; D006801:Humans; D007106:Immune Sera; D007457:Iodine Radioisotopes; D011817:Rabbits; D011863:Radioimmunoassay / Q000379:methods*
chemical_list: D000611:Aminobiphenyl Compounds; D002273:Carcinogens; D007106:Immune Sera; D007457:Iodine Radioisotopes