title: Maternal plasma corticotropin-releasing factor (CRF) and CRF-binding protein (CRF-BP) levels in post-term pregnancy: effect of prostaglandin administration.
abstract: OBJECTIVE
  Placental corticotropin-releasing factor (CRF) affects myometrial contractility and the secretion of several uterotonins such as prostaglandins (PGs); however, the activity of CRF is counteracted by CRF-binding protein (CRF-BP). At term and pre-term labor, CRF levels in maternal plasma are highest whereas those of CRF-BP are falling, and the cause of this fall is unknown. Thus, in this study, we investigated the effect of PG administration for labor induction on maternal plasma CRF and CRF-BP concentrations.
  
  
  METHODS
  Maternal plasma CRF and CRF-BP levels were assayed before and after (2 h later) induction of labor by intracervical administration of prostaglandin E(2) (PGE(2)), and at delivery in a group of healthy post-term pregnancies (n=18). Controls were women at term out of labor (n=22), who subsequently progressed to deliver a healthy singleton baby.
  
  
  METHODS
  CRF was measured by two-site immunoradiometric assay, and CRF-BP was assayed by radioimmunoassay.
  
  
  RESULTS
  Maternal plasma CRF levels were significantly (P<0.0001) lower and CRF-BP significantly (P<0.0005) higher in post-term than in term pregnancies. With respect to induction of labor, 2 mg PGE(2) were sufficient to increase maternal plasma CRF levels at delivery (P<0.005). While 0.5 mg PGE(2) significantly decreased maternal plasma CRF-BP levels at delivery (P<0.001), 2.0 mg PGE(2) significantly reduced CRF-BP concentrations both after 2 h (P<0.05) and at delivery (P<0.0001).
  
  
  CONCLUSIONS
  In the light of the well-known stimulation of prostaglandin release by CRF, these data suggest a positive feedback effect of PGE(2) on maternal CRF release during induced labor.
authors.affiliation: Department of Pediatrics, Section of Obstetrics and Gynecology, Obstetrics and Reproductive Medicine, University of Siena, Policlinico Le Scotte Viale Bracci, 53100, Siena, Italy. florio@unisi.it
authors.forename: P
authors.initials: P
authors.lastname: Florio
authors.forename: P J
authors.initials: PJ
authors.lastname: Lowry
authors.forename: C
authors.initials: C
authors.lastname: Benedetto
authors.forename: L
authors.initials: L
authors.lastname: Galleri
authors.forename: M
authors.initials: M
authors.lastname: Torricelli
authors.forename: A
authors.initials: A
authors.lastname: Giovannelli
authors.forename: R
authors.initials: R
authors.lastname: Battista
authors.forename: F M
authors.initials: FM
authors.lastname: Reis
authors.forename: F
authors.initials: F
authors.lastname: Petraglia
mesh_terms: D000328:Adult; D002352:Carrier Proteins / Q000097:blood*; D003346:Corticotropin-Releasing Hormone / Q000097:blood*; D015232:Dinoprostone / Q000008:administration & dosage* / Q000378:metabolism; D025461:Feedback, Physiological / Q000187:drug effects; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007751:Labor, Induced / Q000379:methods*; D010120:Oxytocics / Q000008:administration & dosage* / Q000378:metabolism; D036801:Parturition / Q000097:blood / Q000187:drug effects; D011247:Pregnancy; D011273:Pregnancy, Prolonged / Q000097:blood*; D014590:Uterine Contraction / Q000187:drug effects / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D010120:Oxytocics; C067133:corticotropin releasing factor-binding protein; D003346:Corticotropin-Releasing Hormone; D015232:Dinoprostone