title: Increased cerebrospinal fluid concentration of aspartate but decreased concentration of nitric oxide breakdown products in women experiencing visceral pain during active labour.
abstract: The aim of the present study was to investigate some putative neurotransmitters involved in nociception and pain in parturients during active labour experiencing intense visceral pain. The concentration of the excitatory amino acid aspartate was significantly increased, and there was a tendency for an increase in glutamate, in lumbar cerebrospinal fluid (CSF) of parturients in active vaginal labour compared with control patients without pain subjected to elective caesarean section. The CSF concentration of the nitric oxide breakdown product nitrate was significantly decreased in parturients compared with control patients and healthy volunteers. No significant differences in the concentrations of substance P, substance P-endopeptidase or met-enkephalin were detected between parturients and controls. Our data suggest a paradoxical negative relationship between CSF concentrations of excitatory amino acids and nitric oxide in labour pain. The mechanisms behind this finding is unclear at present.
authors.affiliation: Department of Anesthesiology and Intensive Care, Karolinska Hospital/Institute, Stockholm, Sweden.
authors.forename: C
authors.initials: C
authors.lastname: Olofsson
authors.forename: A
authors.initials: A
authors.lastname: Ekblom
authors.forename: G
authors.initials: G
authors.lastname: Ekman-Ordeberg
authors.forename: L
authors.initials: L
authors.lastname: Irestedt
authors.forename: F
authors.initials: F
authors.lastname: Nyberg
authors.forename: U
authors.initials: U
authors.lastname: Ungerstedt
authors.forename: P
authors.initials: P
authors.lastname: Wiklund
mesh_terms: D000328:Adult; D000368:Aged; D000698:Analgesia; D001224:Aspartic Acid / Q000134:cerebrospinal fluid*; D002585:Cesarean Section; D036861:Delivery, Obstetric / Q000379:methods; D004744:Enkephalin, Methionine / Q000134:cerebrospinal fluid; D005260:Female; D006801:Humans; D007743:Labor, Obstetric / Q000134:cerebrospinal fluid / Q000502:physiology*; D008666:Metalloendopeptidases / Q000134:cerebrospinal fluid; D008875:Middle Aged; D009569:Nitric Oxide / Q000134:cerebrospinal fluid*; D010146:Pain / Q000134:cerebrospinal fluid*; D017698:Postmenopause; D011247:Pregnancy; D012016:Reference Values; D013373:Substance P / Q000134:cerebrospinal fluid
chemical_list: D001224:Aspartic Acid; D009569:Nitric Oxide; D013373:Substance P; D004744:Enkephalin, Methionine; D008666:Metalloendopeptidases; C029610:substance P degrading enzyme