-
Views
-
Cite
Cite
HILDEGARD WILSON, MORTIMER B. LIPSETT, Metabolism of Epitestosterone in Man, The Journal of Clinical Endocrinology & Metabolism, Volume 26, Issue 8, 1 August 1966, Pages 902–914, https://doi.org/10.1210/jcem-26-8-902
Close - Share Icon Share
Production rates of epitestosterone (17α-hydroxy-4-androsten-3-one) measured in 4 normal men by the urinary isotope dilution technique averaged 220 μg/day. This was 3 % of the simultaneously determined testosterone production rate of 6.8 mg/day. Administration of human chorionic gonadotropin and of corticotropin increased epitestosterone production by 21 and 29 %, respectively. The daily excretion of epitestosterone in the normal men was ⅓ to ½ that of testosterone. In 3 patients with endocrine abnormalities epitestosterone excretion was elevated and it was 5 times greater than testosterone in 2 of them. Metabolites were sought following an intravenous dose of 6.7 mg labeled epitestosterone. Recovery of radioactivity in raw urine for the 2 days following averaged 92 %. Approximately 50 % of the injected radioactivity was recovered in all neutral extract fractions, mostly as glucuronides. Unchanged epitestosterone glucuronide accounted for almost half of the extracted radioactivity, etiocholanolone plus androsterone represented only about 2%, while 2 transformation products, probably 5β-androstane-3α,17α-diol and 5α-androstane-3α,17α-diol, accounted for about 5%. The sulfate fraction yielded 2.5% of the total epitestosterone recovered. Since both oxidation of the 17α-OH group and reduction of the α,β-unsaturated 3-ketone occur only to a limited extent, epitestosterone is poorly metabolized in man. Plasma testosterone is not a precursor of urinary epitestosterone, and epitestosterone is not metabolized to either 16-androsten-3α-ol or to testosterone.
