title: The clearance of ACTH from the plasma of adult and fetal sheep.
abstract: The disappearance of 125-I-ACTH from the circulation of 4 pregnant and fetal sheep has been followed after a single injection to the ewe or fetus. The mean metabolic clearance rate for the fetus and the ewe was 55 and 34 ml/min/kg respectively, giving a half-life in each case of about 1 min. The higher fetal than maternal arterial plasma ACTH concentration has been ascribed to a higher rate of secretion rather than a reduced rate of clearance compared with the ewe. There was no evidence of placental transfer of immunologically reactive ACTH.
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000008:administration & dosage / Q000097:blood*; D000818:Animals; D005260:Female; D005333:Fetus; D005938:Glucocorticoids / Q000097:blood; D006207:Half-Life; D007275:Injections, Intravenous; D007457:Iodine Radioisotopes; D008431:Maternal-Fetal Exchange; D008657:Metabolic Clearance Rate; D011247:Pregnancy; D011863:Radioimmunoassay; D012756:Sheep; D013997:Time Factors
chemical_list: D005938:Glucocorticoids; D007457:Iodine Radioisotopes; D000324:Adrenocorticotropic Hormone