title: [Concentration of follistatin in maternal serum at term and its expression in placenta].
abstract: OBJECTIVE
  To investigate the possible origin and role of follistatin (FS) in pregnancy.
  
  
  METHODS
  The maternal serum FS levels in menstrual cycle, first trimester (8 - 12 weeks) and term (38 - 41 weeks) were determined by a specific two-site enzyme-linked immunosorbent assay (ELISA). Reverse transcription-polymerase chain reaction (RT-PCR) method was utilized to semi-quantitatively determine FS mRNA levels in the ovaries and placentas.
  
  
  RESULTS
  Maternal serum FS level at term was significantly higher than that in the first trimester of pregnancy and that in normal women during the menstrual cycle (180 +/- 26) micro g/L, (4.4 +/- 2.1) micro g/L, (1.5 +/- 2.2) micro g/L, (respectively P < 0.001). Both placentas and ovaries expressed FS mRNA. Semi-quantitative RT-PCR showed that the expression levels of FS mRNA in placenta were higher than that in ovary of same period, but lower than that in ovary of menstrual phase (0.8 +/- 0.4, 0.4 +/- 0.3, 0.93 +/- 0.13, respectively P < 0.05).
  
  
  CONCLUSIONS
  Fetal-placental unit may be the major source of maternal serum FS. The relatively higher levels of FS in the placentas at term may reflect important roles in modulating the development of embryo and the function of placenta.
authors.affiliation: Department of Obstetrics and Gynecology, Second Affiliated Hospital, China Medical University, Shenyang 110001, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Shang
authors.forename: Liang
authors.initials: L
authors.lastname: Zhao
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.forename: Zhong-hui
authors.initials: ZH
authors.lastname: Liu
mesh_terms: D000328:Adult; D005260:Female; D038681:Follistatin / Q000097:blood* / Q000235:genetics; D006801:Humans; D010053:Ovary / Q000378:metabolism; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D038681:Follistatin; D012333:RNA, Messenger