Identification of nociceptin in human cerebrospinal fluid: comparison of levels in pain and non-pain states.
We have measured plasma and cerebrospinal fluid (CSF) concentrations of nociceptin, the endogenous agonist of the orphan opioid receptor-like receptor (ORL-1). We studied two groups of ten patients presenting for elective Caesarean section (Group E) or in established labour and requiring combined spinal epidural anaesthesia for pain relief (Group L). Nociceptin was identified in all CSF samples with mean +/- SD concentrations of 52.49 +/- 34.25 and 63.39 +/- 33.26 pg/ml in groups E and L, respectively. Nociceptin was identified in 16/20 plasma samples with mean +/- SD concentrations of 7.59 +/- 21.58 and 13 73 +/- 23.79 pg/ml in groups E and L, respectively. CSF concentrations were significantly higher than plasma concentrations and there were no differences between groups E and L. These data report the first measurements of CSF nociceptin in man and show no association with the acute pain of labour.
Brooks
H
H
NHS Division of Anaesthesia, Leicester Royal Infirmary, Leicester, LE1 5WW, UK Parke-Davis Neuroscience Research Centre, Cambridge University Forvie Site, Robinson Way, Cambridge, CB2 2QB, UK University Department of Anaesthesia and Pain Management, Leicester Royal Infirmary, Leicester, LE 1 5WW, UK.
Elton
D C
DC
Smart
D
D
Rowbotham
J D
JD
McKnight
T A
TA
Lambert
G D
GD
D000328:Adult; D000767:Anesthesia, Epidural; D002585:Cesarean Section; D005260:Female; D006801:Humans; D007743:Labor, Obstetric / Q000134:cerebrospinal fluid / Q000502:physiology; D008297:Male; D018847:Opioid Peptides / Q000134:cerebrospinal fluid*; D009994:Osmolar Concentration; D010146:Pain / Q000134:cerebrospinal fluid* / Q000503:physiopathology; D010166:Palliative Care / Q000379:methods; D011247:Pregnancy; D011863:Radioimmunoassay; D012016:Reference Values; D000097629:Nociceptin
D018847:Opioid Peptides; D000097629:Nociceptin