title: Effects of oestrogen on urinary thyrosine excretion.
abstract: The day to day variation and the effects of oestrogen on the urinary excretion of thyroxine (T-4) were studied in euthyroid women and men. Serial urinary T-4 values over a period of 28 consecutive days were found to lie within relatively narrow limits except for a transient increase during menstruation in women. During oestrogen therapy urinary T-4 was unchanged, but an appreciable rise was seen after stopping oral ovulation inhibitors in women. A similar effect was seen in men after three days' treatment with 20 mug/day of ethinyloestradiol. The increased urinary T-4 excretion on oestrogen withdrawal reached a maximum in one to three days. This response contrasted with that produced by phenytoin, a drug known to bind to thyroxine binding globulin, and which resulted in increased urinary T-4 excretion during the period that it was being administered.
mesh_terms: D000328:Adult; D003276:Contraceptives, Oral / Q000494:pharmacology; D004967:Estrogens / Q000494:pharmacology*; D004997:Ethinyl Estradiol / Q000494:pharmacology; D005260:Female; D006801:Humans; D008297:Male; D008598:Menstruation; D010672:Phenytoin / Q000494:pharmacology; D013960:Thyroid Function Tests; D013974:Thyroxine / Q000097:blood / Q000652:urine*; D013975:Thyroxine-Binding Proteins; D014284:Triiodothyronine / Q000378:metabolism
chemical_list: D003276:Contraceptives, Oral; D004967:Estrogens; D013975:Thyroxine-Binding Proteins; D014284:Triiodothyronine; D004997:Ethinyl Estradiol; D010672:Phenytoin; D013974:Thyroxine