Influence of Daily Variation in the Metabolism of Dehydroisoandrosterone Upon the Determination of Its Secretory Rate

Abstract

This study was undertaken to determine the influence of daily variation in the metabolism of dehydroisoandrosterone upon the determination of its secretory rate. For this purpose, 7α-H³-dehydroisoandrosterone was injected at one time of day and 4-C¹⁴- dehydroisoandrosterone was injected at another time of the same day in 4 experiments. The H³/C¹⁴ ratios in the urinary metabolites of dehydroisoandrosterone were determined and compared with those of the injected tracers. The results indicate that there is no demonstrable variation during the day in the catabolism of dehydroisoandrosterone to urinary androsterone or etiocholanolone. There was moderate variation in the conversion to urinary dehydroisoandrosterone, but of insufficient magnitude to affect significantly the estimation of the secretory rate of dehydroisoandrosterone from the specific activity of urinary dehydroisoandrosterone.