title: Methods to observe and weaken the influence of pregnancy-associated plasma protein-A on endothelial cell function.
abstract: OBJECTIVE
  To investigate the effect of pregnancy-associated plasma protein-A (PAPP-A) on human umbilical vein endothelial cell (HUVEC) contraction and relaxation function. We also investigated some effects of pregnancy serum, which was voluntarily provided by women who were 9 months pregnant, on PAPP-A function and endothelial cell function.
  
  
  METHODS
  HUVECs were cultured in vitro with PAPP-A at 0, 50, 100, and 200 ng/mL for 0, 12, 24, 48 hours. HUVECs were also pretreated for 12 hours with pregnancy serum before in vitro culture in the presence or absence of PAPP-A (50 ng/mL). Nitric oxide (NO) levels in cell supernatants were assessed using spectrophotometry. Endothelin-1 (ET-1) levels were determined using immunohistochemistry assays and quantified by mean optical density (MOD).
  
  
  RESULTS
  The NO levels of HUVECs in the PAPP-A groups were significantly lower compared to the control group (P<0.05), whereas ET-1 levels in PAPP-A HUVECs were significantly higher compared to the control group (P<0.05.) Additionally, these effects were dose-dependent. The NO levels of HUVECs in the PAPP-A groups with pregnancy serum were higher compared to the control group (P<0.05). ET-1 levels in PAPP-A HUVECs with pregnancy serum were lower than in the control group (P<0.05).
  
  
  CONCLUSIONS
  PAPP-A may affect HUVEC contraction and relaxation by reducing NO secretion and increasing ET-1 levels. In addition, pregnancy serum may affect PAPP-A function on vascular endothelial cells.
authors.affiliation: Department of Cardiology, Third Xiangya Hospital of Central South University, Changsha, China.
authors.forename: Li-ping
authors.initials: LP
authors.lastname: Peng
authors.affiliation: Department of Cardiology, Third Xiangya Hospital of Central South University, Changsha, China yangkanxy3@gmail.com.
authors.forename: Kan
authors.initials: K
authors.lastname: Yang
authors.affiliation: Department of Cardiology, Third Xiangya Hospital of Central South University, Changsha, China.
authors.forename: Wei-hong
authors.initials: WH
authors.lastname: Jiang
authors.affiliation: Department of Nephrology, Third Xiangya Hospital of Central South University, Changsha, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Yi
mesh_terms: D000704:Analysis of Variance; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D019332:Endothelin-1 / Q000378:metabolism; D005260:Female; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects*; D006801:Humans; D009569:Nitric Oxide / Q000378:metabolism; D011247:Pregnancy / Q000097:blood; D011266:Pregnancy-Associated Plasma Protein-A / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D019332:Endothelin-1; D009569:Nitric Oxide; D011266:Pregnancy-Associated Plasma Protein-A; C579283:PAPPA protein, human
keywords: endothelin-1; nitric oxide; pregnancy serum; pregnancy-associated plasma protein-A (PAPP-A); vascular endothelial cell