title: Effect of intravenous general anaesthesia with epidural block on the expression of pre-endogenous opioid peptide genes.
abstract: OBJECTIVE
  To measure the plasma concentrations of three endogenous opioid peptides and the levels of preproenkephalin (PPE) and preprodynorphin (PPD) mRNA in peripheral blood lymphocytes of patients during scheduled surgery performed under intravenous general anaesthesia combined with an epidural block.
  
  
  METHODS
  Patients were anaesthetized and arterial blood was collected at 0 (baseline), 20, 40, 60, and 80 min during surgery. The plasma concentrations of β-endorphin, leucine-enkephalin and dynorphin A were measured using radioimmunoassay. Reverse transcription-polymerase chain reaction was used to measure the levels of PPD and PPE mRNA in peripheral blood lymphocytes collected during surgery.
  
  
  RESULTS
  Fifteen patients participated in this prospective study. The plasma concentrations of β-endorphin were significantly lower at all time-points compared with the baseline value. The plasma concentrations of leucine-enkephalin and dynorphin A were significantly lower at 40, 60, and 80 min compared with baseline. The PPD/β-actin ratio was significantly lower at 80 min compared with baseline, while the PPE/β-actin ratio showed no significant change.
  
  
  CONCLUSIONS
  The level of mRNA from two pre-endogenous opioid peptide genes either decreased or remained unchanged during surgery under intravenous general anaesthesia with epidural block, suggesting that patients remained pain free during surgery.
authors.affiliation: Department of Anaesthesiology, Cancer Hospital, Shanghai Medical College, Fudan University, Shanghai, China chzhygg@sina.cn.
authors.forename: Zhi-Yang
authors.initials: ZY
authors.lastname: Chen
authors.affiliation: Department of Anaesthesiology, Taizhou First People's Hospital, Taizhou, Zhejiang Province, China.
authors.forename: Huaqing
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Anaesthesiology, Taizhou First People's Hospital, Taizhou, Zhejiang Province, China.
authors.forename: Weiping
authors.initials: W
authors.lastname: Xu
authors.affiliation: Department of Anaesthesiology, Taizhou First People's Hospital, Taizhou, Zhejiang Province, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Xu
authors.affiliation: Department of Anaesthesiology, Taizhou First People's Hospital, Taizhou, Zhejiang Province, China.
authors.forename: Xinchun
authors.initials: X
authors.lastname: Fu
mesh_terms: D000005:Abdomen / Q000601:surgery; D000328:Adult; D000767:Anesthesia, Epidural; D000768:Anesthesia, General; D018686:Anesthetics, Intravenous; D002045:Bupivacaine; D004399:Dynorphins / Q000097:blood* / Q000235:genetics; D004743:Enkephalin, Leucine / Q000097:blood* / Q000235:genetics; D004745:Enkephalins / Q000097:blood* / Q000235:genetics; D005260:Female; D005283:Fentanyl; D015870:Gene Expression; D006801:Humans; D008297:Male; D008874:Midazolam; D008875:Middle Aged; D010146:Pain / Q000097:blood / Q000235:genetics / Q000503:physiopathology / Q000517:prevention & control*; D011446:Prospective Studies; D011498:Protein Precursors / Q000097:blood* / Q000235:genetics; D012333:RNA, Messenger / Q000097:blood* / Q000235:genetics; D011863:Radioimmunoassay; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014673:Vecuronium Bromide; D001615:beta-Endorphin / Q000097:blood* / Q000235:genetics
chemical_list: D018686:Anesthetics, Intravenous; D004745:Enkephalins; D011498:Protein Precursors; D012333:RNA, Messenger; C036448:pre-prodynorphin; D004743:Enkephalin, Leucine; D001615:beta-Endorphin; D004399:Dynorphins; D014673:Vecuronium Bromide; C033660:preproenkephalin; D008874:Midazolam; D005283:Fentanyl; D002045:Bupivacaine
keywords: Pre-endogenous opioid peptides; dynorphin A; epidural block; intravenous general anaesthesia; leucine-enkephalin; β-endorphin