title: [Placental permeability in rats and rabbits for thyroid hormones at different periods of pregnancy].
abstract: Upon the introduction of 14C-thyroxine in the rats on the 20th day of pregnancy, about 1/7 of the introduced radioactivity is found in the blood serum of the foetus; the labelled hormone is found in the foetus organs. The permeability of placenta at different times of pregnancy was also studied in rabbits. The placenta was shown to be permeable on the 23rd and 28th days of pregnancy, whereas earlier (16-17th days of development) negligible amounts of the labelled thyroxine introduced in the mother are found in the foetus organs.
mesh_terms: D000818:Animals; D002250:Carbon Radioisotopes; D005260:Female; D005333:Fetus / Q000378:metabolism; D010920:Placenta / Q000187:drug effects*; D011247:Pregnancy; D011817:Rabbits; D051381:Rats; D013974:Thyroxine / Q000378:metabolism; D014018:Tissue Distribution
chemical_list: D002250:Carbon Radioisotopes; D013974:Thyroxine
vernacular_title: Pronitsaemost' platsenty krys i krolikov dlia tireoidnykh gormonov na raznykh srokakh beremennosti.