The Measurement of l Iß, 17ß-Dihydroxy-4-androsten-3-one (llß-Hydroxytestosterone) by Radioimmunoassay in Human Plasma

Summary: A radioimmunoassay (RIA) is described for the measurement of llß,17ß-dihydroxy-4-androsten-3-one (llß-hydroxytestosterone) in human plasma. The reliability criteria of the new RIA were similar to those of other steroid hormone radioimmunoassays. The mean plasma llß,17ß-dihydroxy-4-androsten-3-one level for healthy young subjects was 1.31 ± 0.32 nmol/1 (x ± SD) in males and 1.19 ± 0.35 nmol/1 in females at 8 a. m.; during the night, there was a marked decrease, and at 11 p. m. the recorded values were 0.41 ± 0.15 nmol/1 and 0.46 ± 0.14 nmol/1, respectively. During the corticotropin Stimulation test, llß,17ß-dihydroxy-4-androsten-3-one increased from 1.03 ± 0.33 nmol/1 to 1.31 ± 0.41 nmol/1, while in dexametha-sone suppression tests a decrease from 2.04 ± 0.82 nmol/1 to 0.25 ± 0.05 nmol/1 was seen. In contrast, | chorionic gonadotropin administration on 3 consecutive days did not influence plasma concentrations of f 11 ß,17ß-dihydroxy-4-androsten-3-one. Radioimmunoassay zur Messung von llßf i7ß-Dihydroxy-4-androsten-3-on (llß-Hydroxytestosteron) im Plasma des Mensche