title: Chorionic gonadotropin secretion by human embryos in vitro.
abstract: Embryos (n = 38) from an in vitro fertilization (IVF) program, unsuitable for transfer or cryopreservation, were maintained in culture for 14 days. The time course of hCG secretion into culture fluid was compared to observed embryo development. The earliest significant hCG rise was detected at day 7 post insemination for a partially hatched blastocyst, with hCG levels increasing 50-fold following blastocyst attachment to the surface of the culture vessel. Secretion of hCG was amplified by the addition of serum. There was no significant free alpha hCG or beta hCG secretion between days 6-12. We conclude that hCG production depends on the pathway of cytotrophoblast differentiation and commences with the appearance of the G1 phase in embryonic cells at the late blastocyst stage.
authors: Department of Pathology, Royal Women's Hospital, Melbourne, Australia.
authors: D L
authors: DL
authors: Hay
authors: A
authors: A
authors: Lopata
mesh_terms: D006063:Chorionic Gonadotropin / Q000378:metabolism*; D018997:Chorionic Gonadotropin, beta Subunit, Human; D004622:Embryo, Mammalian / Q000378:metabolism*; D005314:Embryonic and Fetal Development; D015292:Glycoprotein Hormones, alpha Subunit / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D010446:Peptide Fragments / Q000378:metabolism
chemical_list: D006063:Chorionic Gonadotropin; D018997:Chorionic Gonadotropin, beta Subunit, Human; D015292:Glycoprotein Hormones, alpha Subunit; D010446:Peptide Fragments