Progesterone dependence and extratrophoblastic origin of pregnancy-associated plasma protein-A (PAPP-A) in early pregnancy.
Pregnancy-associated plasma protein-A (PAPP-A) is a macromolecular glycoprotein produced in increasing concentration as pregnancy advances. PAPP-A is not specific to pregnancy since measurable levels have been found in non-pregnant females and in males. In non-pregnant females, PAPP-A is probably produced by the endometrium. The origin of PAPP-A in pregnant women is still controversial. In-vitro trophoblast and decidual explants both produce PAPP-A. So far, it is not known if the same applies to the in-vivo situation and to what extent these two tissues contribute to the circulating levels of PAPP-A. This study compares the circulating concentrations of PAPP-A and beta-hCG and progesterone in different pathological situations. In hydatidiform moles, beta-hCG levels are very high demonstrating an intense trophoblastic activity, whereas PAPP-A levels remain in the normal range. With spontaneous abortions, beta-hCG levels decline to very low values whereas PAPP-A continues to increase. These observations furnish indirect evidence for a major contribution to circulating PAPP-A levels by extratrophoblastic sites. Furthermore, PAPP-A levels decrease after administration of an anti-progesterone (RU486) either in-vivo or in-vitro. This is considered as a proof that PAPP-A levels in early pregnancy are progesterone dependent.
P
P
Bischof
A M
AM
Schindler
R
R
Wyss
W L
WL
Herrmann
P C
PC
Sizonenko
D000021:Abortifacient Agents, Steroidal; D000026:Abortion, Habitual / Q000097:blood; D000028:Abortion, Induced; D000293:Adolescent; D000328:Adult; D006063:Chorionic Gonadotropin / Q000097:blood; D046508:Culture Techniques; D003656:Decidua / Q000378:metabolism; D004963:Estrenes; D005260:Female; D006801:Humans; D006828:Hydatidiform Mole / Q000097:blood; D008875:Middle Aged; D015735:Mifepristone; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000378:metabolism*; D011261:Pregnancy Trimester, First; D011266:Pregnancy-Associated Plasma Protein-A / Q000378:metabolism*; D011374:Progesterone / Q000097:blood*; D011388:Prolactin / Q000097:blood; D014327:Trophoblasts / Q000378:metabolism*; D014594:Uterine Neoplasms / Q000097:blood
D000021:Abortifacient Agents, Steroidal; D006063:Chorionic Gonadotropin; D004963:Estrenes; D011257:Pregnancy Proteins; D015735:Mifepristone; D011374:Progesterone; D011388:Prolactin; D011266:Pregnancy-Associated Plasma Protein-A