Fetal hypophysis as the main source of serum TSH in fetal rat.
Decapitation performed at days 17-18 leads to a drastic drop (82%) in blood TSH of 19 and 21-day-old rat fetuses below the mother's level. 125I-TSH injected at 21 days into the mother's bloodstream is not found in fetal blood. The fetal hypophysis is the main source of fetal plasmatic TSH.
D000818:Animals; D005260:Female; D005312:Fetal Blood / Q000378:metabolism*; D007457:Iodine Radioisotopes; D008431:Maternal-Fetal Exchange; D010902:Pituitary Gland / Q000196:embryology* / Q000502:physiology; D011247:Pregnancy; D051381:Rats; D011919:Rats, Inbred Strains; D013972:Thyrotropin / Q000097:blood*
D007457:Iodine Radioisotopes; D013972:Thyrotropin