Radioimmunoassay of urinary testosterone glucuronoside

Abstract

A simple method is described for the determination of testosterone glucuronoside in urine without prior hydrolysis or extraction. Appropriate amounts (5 μl male, 50 μ1 female urine) are dried at 100 °C to eliminate nonspecific binding by urinary proteins. The residues are cooled, redissolved in buffer and equilibrated with antiserum to testosterone-17β-glucosiduronate-bovine serum albumin and tritiated testosterone glucuronoside. The unbound steroid is removed with dextran-coated charcoal. The total random theoretical percentage error was calculated as 7 %. The inter and intra assay precision were 18 and 9 % respectively. Daily urine collections from 8 complete menstrual cycles have been analysed and the results related to the peak of urinary LH. In seven subjects, there was a visible peak of testosterone glucuronoside at mid cycle (LH peak ± 1 day), in six a distinct peak in the luteal phase, and in five a smaller peak during the follicular phase. The levels of testosterone glucuronoside in groups of healthy men and women were 273 ± 169 and 19 ± 10 μg/24 hrs. The corresponding range of values by a gas-liquid chromatographic method were 204 ± 102 and 14 ± 8. The values are discussed.