Presence of pro-opiomelanocortin peptides and corticotropin-releasing factor in human placenta.
Immunoreactive adrenocorticotropin (ACTH), beta-endorphin (BEP) and corticotropin-releasing factor (CRF) were detected in human term placenta obtained from elective Caesarian surgery. The concentrations of ACTH, BEP and CRF in placenta detected by radioimmunoassay (RIA) were 2.83 +/- 0.36, 0.52 +/- 0.05 and 0.56 +/- 0.15 ng/g wet weight of tissue respectively. Pro-opiomelanocortin (POMC) peptides were also detected in the amnion and chorion membranes and in the decidua. The concentrations of ACTH were 1.72 +/- 0.20, 4.43 +/- 0.39 and 5.80 +/- 0.17 ng/g and the levels of BEP were 0.42 +/- 0.18, 0.65 +/- 0.20 and 3.66 +/- 1.10 ng/g in the amnion, chorion and decidua respectively. In contrast to placenta, immunoreactive CRF was not detected in the amnion, chorion and decidua. Immunoreactive N-acetylated BEP was also not detected in all the placental subfractions. Comparison of the amounts of both ACTH and BEP in the various placental components indicated the following distribution: decidua > chorion > placenta > amnion. In decidua, POMC peptides were present in an equi-molar ratio but in the other three placental fractions, ACTH levels were three to five-fold higher than BEP. In immunohistochemical studies, only a positive staining for ACTH was obtained for decidua. Our results confirm the presence of POMC peptides and CRF in placenta and their physiological roles in pregnancy and parturition.
Ng
M L
ML
Department of Biochemistry, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia.
Healy
D L
DL
Rajna
A
A
Fullerton
M
M
O'Grady
C
C
Funder
J W
JW
D000324:Adrenocorticotropic Hormone / Q000378:metabolism; D000328:Adult; D003346:Corticotropin-Releasing Hormone / Q000378:metabolism*; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D010455:Peptides / Q000378:metabolism; D010920:Placenta / Q000378:metabolism* / Q000473:pathology; D011247:Pregnancy; D011333:Pro-Opiomelanocortin / Q000378:metabolism*; D001615:beta-Endorphin / Q000031:analogs & derivatives / Q000378:metabolism
D010455:Peptides; D001615:beta-Endorphin; D011333:Pro-Opiomelanocortin; C035101:N-acetyl-beta-endorphin; D000324:Adrenocorticotropic Hormone; D003346:Corticotropin-Releasing Hormone