The metabolism in man of (3H)-5alpha-16-androsten-3alpha-ol and of (3H)-5alpha-16-androsten-3-one.

The in vitro metabolism in man of two 16-androstene steroids, 5alpha-16-androsten-3-one and 5alpha-16-androsten-3alpha-ol, has been studied using 3H-labelled tracers. 4 healthy subjects (2 of each sex) were chosen, and each labelled steroid was administered, by a single injection, to 1 man and 1 woman. Disappearance of (3H)-3alpha-androstenol in the subjects receiving this compound followed a curve which indicated a two-pool distribution in both cases; metabolic clearance rates for these subjects were found to be 3,790 1/24 h in the man and 3,120 1/24 h in the woman. Blood production rates calculated for the 3alpha-androstenol-treated subjects were 875 microgram/24 h in the man and 1,780 microgram/24 h in the woman. Recovery of 3H in the urine of all 4 subjects was very low, between 28 and 42%. Conversion of the injected precursors to urinary 3alpha-androstenol was 13.5 and 12.7% in the 2 men and 6.1 and 5.9% in the 2 women. The male subjects were found to have a lower 24-hour urinary 3alpha-androstenol output (570 and 387 microgram/24 h) than the average for men of their age. The urinary 3alpha-androstenol output in the women was 225 and 276 microgram/24 h, and was within the normal range for women. The urine production rates of 3alpha-androstenol were 2,470 and 4,090 microgram/24 h in the male and female subjects, respectively; the difference between the blood and urine production rates of this compound are thought to indicate the direct secretion of conjugates. Urine production rates of 5alpha-androstenone (measured as 3alpha-androstenol) were 2,370 and 4,340 microgram/24 h in the male and female subjects, respectively.