title: Neuroprotective effects of racemic ketamine and (S)-ketamine on spinal cord injury in rat.
abstract: BACKGROUND
  The aim of this study was to investigate and to compare the potential neuroprotective effects of racemic ketamine, (S)-ketamine and methylprednisolone after an experimental spinal cord injury model in rats.
  
  
  METHODS
  Fifty-nine Wistar albino rats were divided into three main groups as acute stage (A), subacute stage (SA) and sham groups and then acute and subacute stage groups were divided into four groups regarding the used drug as control (CONT), racemic ketamine (RK), (S)-ketamine (SK) and methylprednisolone (MP) groups. A dorsal laminectomy was performed; and spinal cord injury was induced by using a temporary aneurysm clip. Four hours later from the clip compression, except those of the sham and control groups, the drugs (60 mg/kg racemic ketamine, 60 mg/kg (S)-ketamine or 30 mg/kg methylprednisolone) were administered intraperitoneally. At 72th h and 7th days of the study, the spinal cords of rats were removed from T8 level to the conus medullaris level. The specimens were and evaluated histopathologically, tissue lipid peroxidation (LPO) and myeloperoxidation (MPO) levels were measured and biochemically.
  
  
  RESULTS
  The histopathological results were similar both in the acute and in the subacute stage groups. There was a statistically significant difference among all groups regarding the tissue LPO levels (p<0.001). There was a statistically significant difference between the CONT-A group and the MP-A, RK-A and SK-A groups (p=0.004, p<0.001 and p=0.007, respectively) in acute stage and between the CONT-SA group and SK-SA group (p=0.002) in subacute stage. There was a statistically significant difference among all groups regarding the tissue MPO levels (p=0.001). The median MPO levels were similar among acute stage groups (p=0.057), but there was a statistical difference among subacute stage groups (p=0.046).
  
  
  CONCLUSIONS
  (S)-ketamine is more effective than methylprednisolone and racemic ketamine to reduce the LPO levels in subacute stage of spinal cord injury in rats. And, it is as effective as methylprednisolone in preventing secondary spinal cord injury histopathologically.
authors.affiliation: Kirikkale University, School of Medicine, Department of Anaestesiology and Reanimation, Kirikkale, Turkey. arzuhct@hotmail.com
authors.forename: Emine Arzu
authors.initials: EA
authors.lastname: Kose
authors.forename: Bulent
authors.initials: B
authors.lastname: Bakar
authors.forename: Sebnem Kupana
authors.initials: SK
authors.lastname: Ayva
authors.forename: Kamer
authors.initials: K
authors.lastname: Kilinc
authors.forename: Alpaslan
authors.initials: A
authors.lastname: Apan
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D007274:Injections, Intraperitoneal; D007649:Ketamine / Q000008:administration & dosage / Q000494:pharmacology*; D007796:Laminectomy; D015227:Lipid Peroxidation / Q000187:drug effects*; D008297:Male; D008775:Methylprednisolone / Q000008:administration & dosage / Q000494:pharmacology*; D009043:Motor Activity; D009048:Motor Skills / Q000187:drug effects*; D018696:Neuroprotective Agents / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013119:Spinal Cord Injuries / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology
chemical_list: D018696:Neuroprotective Agents; D007649:Ketamine; D008775:Methylprednisolone