title: Ketamine inhibits proliferation of neural stem cell from neonatal rat hippocampus in vitro.
abstract: OBJECTIVE
  Ketamine is a widely used anesthetic in obstetric and pediatric anesthesia. In the developing brain, the widespread neuron apoptosis triggered by ketamine has been demonstrated. However, little is known about its effect on neural stem cells (NSCs) function. This study aimed to investigate the effect of ketamine on proliferation of NSCs from neonatal rat hippocampus.
  
  
  METHODS
  Neural stem cells were isolated from the hippocampus of Sprague-Dawley rats on postnatal day 3. In dose-response experiments, cultured neural stem cells (NSCs) were exposed to different concentrations of ketamine (0-1000 µM) for 24 hrs. The proliferative activity of NSCs was evaluated by 5-Bromo-2'-deoxyuridine (BrdU) incorporation assay. Apoptosis of neural stem cells were assessed using caspase-3 by western blot. The intracellular Ca(2+) concentration ([Ca(2+)]i) in NSCs was analyzed by flow cytometry. The activation of protein kinase C-α (PKCα) and the phosphorylation of extracellular signal-regulated kinases 1/2 (ERK1/2) were measured by western blot analysis.
  
  
  RESULTS
  Clinical relevant concentration of ketamine (10, 20 and 50 µM) did not markedly alter the proliferation of NSCs from neonatal rat hippocampus in vitro. However, ketamine (200, 500, 800 and 1000μM) significantly inhibited the proliferation of NSCs and did not affect the expression of caspase-3. Meanwhile, ketamine (200, 500, 800 and 1000μM) also markedly decreased [Ca(2+)]i as well as suppressed PKCα activation and ERK1/2 phosphorylation in NSCs. A combination of subthreshold concentrations of ketamine (100 μM) and Ca(2+) channel blocker verapamil (2.5 μM), PKCα inhibitor chelerythrine (2.5 μM) or ERK1/2 kinase inhibitor PD98059 (5 μM) significantly produced suprathreshold effects on PKCα activation, ERK1/2 phosphorylation and NSC proliferation.
  
  
  CONCLUSIONS
  Ketamine inhibited proliferation of NSCs from neonatal rat hippocampus in vitro. Suppressing Ca(2+)-PKCα-ERK1/2 signaling pathway may be involved in this inhibitory effect of ketamine on NSCs proliferation.
authors.affiliation: Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical College, Xuzhou, P R. China.
authors.forename: Yu-Qing
authors.initials: YQ
authors.lastname: Wu
authors.forename: Tuo
authors.initials: T
authors.lastname: Liang
authors.forename: He
authors.initials: H
authors.lastname: Huang
authors.forename: Yang-Zi
authors.initials: YZ
authors.lastname: Zhu
authors.forename: Pan-Pan
authors.initials: PP
authors.lastname: Zhao
authors.forename: Chun-Mei
authors.initials: CM
authors.lastname: Xu
authors.forename: Lu
authors.initials: L
authors.lastname: Liu
authors.forename: Xiao-Tian
authors.initials: XT
authors.lastname: Shi
authors.forename: Yu
authors.initials: Y
authors.lastname: Hu
authors.forename: Li
authors.initials: L
authors.lastname: Huang
authors.forename: Cheng-Hua
authors.initials: CH
authors.lastname: Zhou
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects; D002118:Calcium / Q000378:metabolism; D053148:Caspase 3 / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism; D007649:Ketamine / Q000494:pharmacology*; D020935:MAP Kinase Signaling System / Q000187:drug effects; D058953:Neural Stem Cells / Q000187:drug effects* / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D051571:Protein Kinase C-alpha / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D007649:Ketamine; D051571:Protein Kinase C-alpha; D053148:Caspase 3; D002118:Calcium