Measurement of unconjugated testosterone, 5α-dihydrotestosterone and oestradiol in human urine

Abstract

Radioimmunoassay methods for measuring unconjugated testosterone, 5α-dihydro testosterone and oestradiol in human urine are described. The methods have been evaluated and precision, accuracy, recovery and specificity found to be satisfactory. Normal males had mean (range) 24-h values of 377 (76–1154) ng, 138 (51–408) ng and 8.9 (3.2–19) ng for testosterone, 5α-dihydrotestosterone and oestradiol, respectively. Normal females in the early follicular phase of the menstrual cycle had mean (range) 24-h values of 92 (33–260) ng, 39 (11–82) ng and 24 (5.7–75) ng for testosterone, 5α-dihydro testosterone and oestradiol, respectively. Urinary levels of the unconjugated hormones in normal females on oral contraceptives, a small group of hirsute females, and a few normal postmenopausal women are given. While the postmenopausal women had similar values for the androgens to the normal female group the hirsute group had much higher average values which were widely scattered and overlapped with the normal group. The women on oral contraceptives had higher excretion of both androgens than the normal group. There was no difference between values in night and day collections. A highly significant overall correlation ( p < 0.001) was found between testosterone and 5α-dihydro testosterone values. Both androgens showed a significant correlation ( p < 0.02) with urinary creatinine excretion. Unconjugated oestradiol levels showed a poor correlation with the levels of either androgen or the creatinine excretion. Simultaneously obtained serum levels within each group correlated poorly with the urinary levels.