Conjugation of C-14-diethylstilbestrol by chicken liver in vitro

SummaryChicken liver was incubated with C14-labeled diethylstilbestrol (C14-DES). Without incubation 94.6% of the radioactivity was extracted with ethanol while after incubation only 82.6% was removed from the tissue. Partition of the radioactivity between water and ether at pH 7 gave 7% of the counts in water from unincubated tissue and 75% of the counts in water after incubation. Hydrolysis of the aqueous portion with β-glucuronidase and paper chromatography established that the material was conjugated DES. Assay of the extracts for uterotropic activity using immature mice indicated that the conjugate was but 8% as potent as the free compound although incubation caused a 50% loss of estrogenic potency.