title: Low-concentration lidocaine rapidly inhibits axonal transport in cultured mouse dorsal root ganglion neurons.
abstract: BACKGROUND
  Axonal transport plays a critical role in supplying materials for a variety of neuronal functions such as morphogenetic plasticity, synaptic transmission, and cell survival. In the current study, the authors investigated the effects of the analgesic agent lidocaine on axonal transport in neurites of cultured mouse dorsal root ganglion neurons. In relation to their effects, the effects of lidocaine on the growth rate of the neurite were also examined.
  
  
  METHODS
  Isolated mouse dorsal root ganglion cells were cultured for 48 h until full growth of neurites. Video-enhanced microscopy was used to observe particles transported within neurites and to measure the neurite growth during control conditions and in the presence of lidocaine.
  
  
  RESULTS
  Application of 30 microM lidocaine immediately reduced the number of particles transported in anterograde and retrograde axonal directions. These effects were persistently observed during the application (26 min) and were reversed by lidocaine washout. The inhibitory effect was dose-dependent at concentrations from 0.1 to 1,000 microM (IC50 = 10 microM). In Ca2+-free extracellular medium, lidocaine failed to inhibit axonal transport. Calcium ionophore A23187 (0.1 microM) reduced axonal transport in both directions. The inhibitory effects of lidocaine and A23187 were abrogated by 10 microM KN-62, a Ca2+-calmodulin-dependent protein kinase II inhibitor. Application of such low-concentration lidocaine (30 microM) for 30 min reduced the growth rate of neurites, and this effect was also blocked by KN-62.
  
  
  CONCLUSIONS
  Low-concentration lidocaine rapidly inhibits axonal transport and neurite growth via activation of calmodulin-dependent protein kinase II.
authors.affiliation: Department of Anesthesiology, Kitasato University School of Medicine, Sagamihara, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Kanai
authors.forename: H
authors.initials: H
authors.lastname: Hiruma
authors.forename: T
authors.initials: T
authors.lastname: Katakura
authors.forename: S
authors.initials: S
authors.lastname: Sase
authors.forename: T
authors.initials: T
authors.lastname: Kawakami
authors.forename: S
authors.initials: S
authors.lastname: Hoka
mesh_terms: D000779:Anesthetics, Local / Q000494:pharmacology*; D000818:Animals; D001370:Axonal Transport / Q000187:drug effects*; D002118:Calcium / Q000378:metabolism; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000502:physiology; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D005260:Female; D005727:Ganglia, Spinal / Q000187:drug effects* / Q000502:physiology; D008012:Lidocaine / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D016501:Neurites / Q000187:drug effects / Q000502:physiology
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D002118:Calcium