THE ASSAY OF ORALLY ADMINISTERED ANDROGENS USING THE CHICK'S COMB

ABSTRACT A method for the assay of androgens is described whereby the test material mixed with the food is fed for 7 days starting with day-old chicks and the comb weight used as the end-point. When testosterone was assayed against itself, the mean potency ratio for 24 trials, using from 36 to 80 chicks per trial, was 105% (range 69% to 141%). Statistically significant differences could not be found for the slopes, and λ varied from 0.13 to 0.40 (mean = 0.248). The following relative potencies (testosterone = 100) were found: 19-nortestosterone 76, androst-4-ene-3,17-dione 71, methyltestosterone 63, 11α-hydroxy-androst-4-ene-3,17-dione 57, 11β-hydroxy-androst-4-ene-3,17-dione 39, adrenosterone 32, androstane-3,17-dione 24, 17β-hydroxyandrostan-3-one 14, dehydroepiandrosterone 7, epiandrosterone 6, 17α-methyl-androst-5-ene3β,17β-diol 5.