title: Profile of neurokinin B concentrations in maternal and cord blood in normal pregnancy.
abstract: OBJECTIVE
  Neurokinin B (NKB) is a neuropeptide with a vasopressor effect belonging to the tachykinin family. This neuropeptide has attracted attention since recent reports indicated that it is also secreted in the placenta and is probably a cause of pre-eclampsia. To provide a basis for elucidation of the relationship between pre-eclampsia and NKB, this study aimed to clarify the trend of changes in blood NKB levels during normal pregnancy by measuring NKB concentrations in maternal blood during various gestational periods and in umbilical blood.
  
  
  METHODS
  Fifty-nine normal pregnant women, 12 normal puerperal women and 24 nonpregnant women were studied. The normal pregnant women comprised of 24 at 8-20 weeks' gestation (early), 11 at 28-34 weeks (middle) and 24 at 35-40 weeks (late). Plasma was separated from peripheral blood samples, umbilical venous blood samples (n = 24) and umbilical arterial blood samples (n = 9). Peptide fractions were extracted from each plasma sample and NKB concentrations were measured by the radioimmunoassay method.
  
  
  RESULTS
  The NKB concentration in early pregnancy was not significantly different from that in the nonpregnant state. During pregnancy, the blood NKB concentration increased with advance in gestational week, and a correlation was demonstrated by a linear regression equation. The concentration during puerperium was significantly lower than that in late pregnancy. The umbilical blood concentration was significantly higher than the maternal blood concentration in late pregnancy. There was no significant difference between umbilical venous and arterial blood.
  
  
  CONCLUSIONS
  This study demonstrated that NKB secreted from the placenta during pregnancy enters both the maternal and fetal circulation. These results suggest that NKB may modulate fetoplacental haemodynamics through a paracrine mechanism.
authors.affiliation: Department of Obstetrics and Gynecology, Chiba University Hospital, Chiba University School of Medicine, Chiba-shi, Japan.
authors.forename: Rie
authors.initials: R
authors.lastname: Sakamoto
authors.forename: Hisao
authors.initials: H
authors.lastname: Osada
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Iitsuka
authors.forename: Kentarou
authors.initials: K
authors.lastname: Masuda
authors.forename: Kenshi
authors.initials: K
authors.lastname: Kaku
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Seki
authors.forename: Souei
authors.initials: S
authors.lastname: Sekiya
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D005260:Female; D005312:Fetal Blood / Q000378:metabolism*; D005865:Gestational Age; D006801:Humans; D015287:Neurokinin B / Q000097:blood*; D049590:Postpartum Period / Q000097:blood; D011247:Pregnancy / Q000097:blood*; D011264:Pregnancy Trimesters / Q000097:blood; D014469:Umbilical Arteries / Q000378:metabolism; D014471:Umbilical Veins / Q000378:metabolism
chemical_list: D015287:Neurokinin B