title: Permeability of the sheep placenta to 125I-arginine vasopressin.
abstract: We studied the permeability of the ovine placenta to AVP. 125I-AVP (9.3 +/- 1.9 mU) with approximately 82 (+/- 17.3) X 10(6) counts per 5 min were infused intravenously in 6 pregnant ewes. Six blood samples were collected at 10-min intervals over a 1-hour period from chronically catheterized maternal and fetal sheep. 125I-AVP in maternal and fetal plasma samples (1 ml each) were counted in a gammacounter for 5 min. Maternal counts decreased from 9,300 to 2,500 counts per 5 min over the hour following infusion but no increase in radioactivity could be measured in fetal blood, indicating that the sheep placenta is impermeable to 125I-AVP.
mesh_terms: D000818:Animals; D001127:Arginine Vasopressin / Q000378:metabolism*; D005260:Female; D005312:Fetal Blood / Q000378:metabolism; D008431:Maternal-Fetal Exchange; D010539:Permeability; D011247:Pregnancy; D012756:Sheep
chemical_list: D001127:Arginine Vasopressin