title: The effect of heparin on pregnancy associated plasma protein-A concentration in healthy, non-pregnant individuals.
abstract: OBJECTIVE
  The objective of this study was to determine the differences in pregnancy associated plasma protein-A (PAPP-A) concentrations in heparin naive and heparin treated healthy men and non-pregnant women, to find a possible difference in different age groups, and to determine the response in PAPP-A concentration to repeated injections of unfractionated heparin.
  
  
  METHODS
  Twenty-five healthy, non-pregnant volunteers divided into five groups (determined by gender and age) received 5000 IU unfractionated heparin intravenously. Five young men received an additional 5000 IU after 90 and 180 min. Blood samples to determine PAPP-A concentration and APTT were drawn at different time points.
  
  
  RESULTS
  Injection of heparin elicited increase in and rapid normalization of PAPP-A concentrations in all subjects. The group of 20-30-year-old never-pregnant women had lower responses than the individuals of the four other groups. The difference was not significant (p > 0.05). Repeated injections of heparin caused additional peaks in PAPP-A concentration of about the same sizes as the first peak. We observed an increase in time to normalization of PAPP-A concentration (from 75-90 min to 90-150 min) and APTT levels with repeated injections.
  
  
  CONCLUSIONS
  We observed a rapid normalization of PAPP-A. Our result has a great similarity to the half-life of unfractionated heparin. This result combined with the finding of equally sized peaks in PAPP-A concentration, and that all of this was found in healthy, non-pregnant individuals, suggests that heparin might compete for a binding-site on PAPP-A or with PAPP-A itself for a common receptor in healthy arterial vessels.
authors.affiliation: Department of Cardiology, Nordsjællands Hospital Hillerød, Dyrehavevej 29, DK-3400 Hillerød, Denmark. Electronic address: camillahbj@gmail.com.
authors.forename: Camilla H B
authors.initials: CH
authors.lastname: Jespersen
authors.affiliation: Department of Cardiology, Nordsjællands Hospital Hillerød, Dyrehavevej 29, DK-3400 Hillerød, Denmark.
authors.forename: Kirstine R
authors.initials: KR
authors.lastname: Vestergaard
authors.affiliation: Department of Cardiology, Herlev Hospital, Herlev Ringvej 75, DK-2730 Herlev, Denmark.
authors.forename: Morten
authors.initials: M
authors.lastname: Schou
authors.affiliation: Department of Immunology and Microbiology, University of Southern Denmark, JB Winsløws Vej 21-25, DK-5000 Odense C, Denmark.
authors.forename: Børge
authors.initials: B
authors.lastname: Teisner
authors.affiliation: Department of Cardiology, Herlev Hospital, Herlev Ringvej 75, DK-2730 Herlev, Denmark.
authors.forename: Kasper
authors.initials: K
authors.lastname: Iversen
mesh_terms: D000328:Adult; D000367:Age Factors; D004305:Dose-Response Relationship, Drug; D005260:Female; D006493:Heparin / Q000008:administration & dosage*; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D011266:Pregnancy-Associated Plasma Protein-A / Q000378:metabolism*; D012737:Sex Factors
chemical_list: D006493:Heparin; D011266:Pregnancy-Associated Plasma Protein-A; C579283:PAPPA protein, human
keywords: Healthy individuals; PAPP-A; Unfractionated heparin