title: Quantitation of delta 4-reduced metabolite of norethindrone in human plasma by HPLC-RIA.
abstract: An HPLC-RIA method for the measurement of the delta 4-reduced metabolite of norethindrone is described. The sensitivity of the method was such as to permit the quantitation of pg amounts (30 pg with an inter-assay CV of less than 7%). Nineteen volunteers received a single oral dose of 1 mg of norethindrone and, blood samples withdrawn at timed intervals, were pooled for each time period and assayed. The plasma concentrations of the dihydro metabolite ranged from 460 pg/ml at 30 min to 20 pg/ml at 24h.
mesh_terms: D001711:Biotransformation; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D006801:Humans; D009640:Norethindrone / Q000097:blood*; D010084:Oxidation-Reduction; D011863:Radioimmunoassay / Q000379:methods
chemical_list: D009640:Norethindrone