title: Does analgesia and condition influence immunity after surgery? Effects of fentanyl, ketamine and clonidine on natural killer activity at different ages.
abstract: OBJECTIVE
  Cellular immunity varies in the perioperative period. We evaluated the effects of fentanyl, clonidine and ketamine at different time points after surgery and in animals in different conditions (young vs. old).
  
  
  METHODS
  Rats undergoing laparotomy under sevoflurane anaesthesia were assigned to receive saline, fentanyl (40 microg kg(-1)), clonidine (10 microg kg(-1)) or ketamine (10 mg kg(-1)) 1 h before surgery. Natural killer (NK) activity was quantified at different time points (immediately or after 18, 24, 48, 72 h and 8 days) in vitro by the lysis of YAC-1 cells. In-vivo assessment included counting the number of lung metastases induced by the MADB-106 cells.
  
  
  RESULTS
  During the first 24 h after surgery, a rapid increase in NK activity was noted, followed by a significant depression returning to baseline at 8 days. Analgesics show specific effects: fentanyl depressed NK activity with or without surgery. Clonidine depressed NK activity in nonoperated animals and during the first 24 h after surgery. Ketamine depressed NK activity in nonoperated animals but, after surgery, this activity varied with the same time course as saline. Ketamine and clonidine significantly reduced the number of lung metastases in operated animals. Ketamine significantly reduced the number of metastases in old nonoperated animals. Finally, ageing has a significant negative influence.
  
  
  CONCLUSIONS
  Surgery, analgesics and co-existing conditions significantly influence cellular immunity. The importance of these changes varies with time. Fentanyl had a worse influence than clonidine and ketamine, but seemed equally protective against the development of metastases.
authors.affiliation: Department of Anesthesiology, Université Catholique de Louvain, St Luc Hospital, Brussels, Belgium. forgetpatrice@yahoo.fr
authors.forename: Patrice
authors.initials: P
authors.lastname: Forget
authors.forename: Valérie
authors.initials: V
authors.lastname: Collet
authors.forename: Patricia
authors.initials: P
authors.lastname: Lavand'homme
authors.forename: Marc
authors.initials: M
authors.lastname: De Kock
mesh_terms: D000367:Age Factors; D000698:Analgesia / Q000009:adverse effects* / Q000639:trends; D000818:Animals; D003000:Clonidine / Q000633:toxicity; D005283:Fentanyl / Q000633:toxicity; D007111:Immunity, Cellular / Q000187:drug effects / Q000276:immunology; D007649:Ketamine / Q000633:toxicity; D007694:Killer Cells, Natural / Q000187:drug effects* / Q000276:immunology*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012307:Risk Factors
chemical_list: D007649:Ketamine; D003000:Clonidine; D005283:Fentanyl