19-nortestosterone, a model for the use of anabolic steroid conjugates in raising antibodies for radioimmunoassay.
1. The raising of antibodies in Soay sheep to an immunogenic conjugate of 19-nortestosterone-3-(O-carboxymethyl)oxime with bovine serum albumin is described. 2. High titre plasma so obtained can be used for the radioimmunoassay of 19-nortestosterone. 3. Cross-reactivities of the antibody with endogenous steroids is confined to testosterone (20-25%) and 17beta-estradiol (1-2%). Cross-reactivities with a range of other 17beta-hydroxy synthetic anabolic steroids and with some potential 17beta-hydroxy metabolites of 19-nortestosterone vary between 2-3% for 5beta-estrane-3alpha,17beta-diol and 26% for 1-dehydrotestosterone. There is limited cross-reactivity (ca. 1-2%) with anabolic steroids with 17beta-hydroxy, 17alpha-methyl substituents. 4. 19-Nortestosterone (phenyl propionate) administered to a horse (1 mg/kg, intra-muscular) gives urinary metabolites readily detectable by radioimmunoassay, for more than 4 days.
D000818:Animals; D000906:Antibodies; D000918:Antibody Specificity; D004958:Estradiol / Q000276:immunology; D005260:Female; D006736:Horses; D009277:Nandrolone / Q000032:analysis / Q000276:immunology* / Q000378:metabolism; D011863:Radioimmunoassay; D012710:Serum Albumin, Bovine; D012756:Sheep; D013329:Structure-Activity Relationship; D013739:Testosterone / Q000276:immunology
D000906:Antibodies; D012710:Serum Albumin, Bovine; D013739:Testosterone; D004958:Estradiol; D009277:Nandrolone