title: Ethynyl cleavage of 17 alpha-ethynylestradiol in the rhesus monkey.
abstract: 17 alpha-Ethynylestradiol (EE2)[20,21-14C] and [9,11-3H] were administered by intragastric intubation to three adult female rhesus monkeys. Quantification of the tritium isotope indicated that the peak plasma radioactivity (3.4-6.8% of dose) occurred between 30 and 60 min, whereas 36-39% of the administered tritium appeared in the urine in the first 96 hr. Fecal excretion was 9.17.0% during the same period. Fractionation and isolation of the urinary conjugates were accomplished by chromatography on Sephadex LH-20 followed by HPLC. Cochromatography of radioactive fractions with authentic steroid glucuronide standards gave presumptive evidence for the presence of ethynylestradiol and estrone glucuronides. Following hydrolysis, the tritium-labeled natural estrogens, estrone and estradiol-17 beta, were identified with reverse-isotope recrystallization, demonstrating that the de-ethynylation of EE2 had occurred.
mesh_terms: D000818:Animals; D001711:Biotransformation; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004997:Ethinyl Estradiol / Q000378:metabolism* / Q000652:urine; D005243:Feces / Q000032:analysis; D005260:Female; D005965:Glucuronates / Q000378:metabolism; D008253:Macaca mulatta; D013997:Time Factors
chemical_list: D005965:Glucuronates; D004997:Ethinyl Estradiol