Changes in amino acids and nitric oxide concentration in cerebrospinal fluid during labor pain

Neurochem Res. 2006 Sep;31(9):1127-33. doi: 10.1007/s11064-006-9133-8. Epub 2006 Aug 29.


This study analyzes the relationship between amino acids and pain perception during active labor. Cerebrospinal fluid (CSF) levels of the excitatory amino acids (EAAs)-glutamate, aspartate and their amide forms, inhibitory amino acids (IAAs)-glycine, gamma-amino butyric acid (GABA) and taurine and nitric oxide (NO) related compounds-arginine and citrulline (by-product of NO synthesis) were compared between pregnant women at term pregnancy with labor pain (n = 38) and without labor pain (Caesarian section; n = 30). The levels of aspartate, glycine, GABA and citrulline were significantly higher; whilst taurine was significantly lower in the labor pain group. These findings suggest that aspartate and NO are associated with labor pain. An inhibitory role for the IAA taurine and a pronociceptive role for glycine in labor pain are proposed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acids / cerebrospinal fluid*
  • Female
  • Humans
  • Labor Pain / cerebrospinal fluid*
  • Nitric Oxide / cerebrospinal fluid*
  • Pregnancy


  • Amino Acids
  • Nitric Oxide