title: Release of a substance from the human placenta having digoxin-like immunoreactivity.
abstract: 1. The human placental lobule, perfused with a constant flow (5 mL/min) of Krebs' solution after delivery at term, released into the fetal perfusate a digoxin-like substance, as measured by a fluorescence polarization immunoassay. 2. Initially the venous concentration was 360 +/- 66.7 pmol/L digoxin equivalents. This level did not change significantly during fetal vasoconstriction induced by prostaglandin F2 alpha infusion and persisted for the duration of the experiment (1.5-2 h). 3. Infusion into the fetal circulation of Fab fragments of sheep antibodies to digoxin caused vasodilatation, indicated by a fall in perfusion pressure. 4. Thus a digoxin-like immunoreactive substance, previously reported to be present in the placenta, is released into the fetal circulation and may play a role in placental control of fetal vascular tone.
authors.affiliation: Discipline of Reproductive Medicine, University of Newcastle, Callaghan, New South Wales, Australia.
authors.forename: A
authors.initials: A
authors.lastname: Di Grande
authors.forename: A L
authors.initials: AL
authors.lastname: Boura
authors.forename: M A
authors.initials: MA
authors.lastname: Read
authors.forename: L S
authors.initials: LS
authors.lastname: Malatino
authors.forename: W A
authors.initials: WA
authors.lastname: Walters
mesh_terms: D000293:Adolescent; D000328:Adult; D001798:Blood Proteins / Q000378:metabolism*; D002298:Cardenolides; D004077:Digoxin; D015237:Dinoprost / Q000494:pharmacology; D005260:Female; D005312:Fetal Blood / Q000378:metabolism; D016231:Fluorescence Polarization Immunoassay; D006801:Humans; D010477:Perfusion; D010920:Placenta / Q000098:blood supply / Q000187:drug effects / Q000378:metabolism*; D012503:Saponins; D014661:Vasoconstriction / Q000187:drug effects; D014664:Vasodilation; D014680:Veins
chemical_list: D001798:Blood Proteins; D002298:Cardenolides; D012503:Saponins; C034504:digoxin-like factors; D004077:Digoxin; D015237:Dinoprost