title: [Effects of gabapentin on high-voltage-activated calcium current in dorsal root ganglion neurons in rats].
abstract: OBJECTIVE
  To compare the effects of gabapentin on high-voltage-activated calcium (HVA) current in dorsal root ganglion (DRG) neurons in normal and nerve-injured rats and understand the reasons of their differences.
  
  
  METHODS
  Pathogen-free male SD rats (weight 180 - 220 mg) aged 4 - 6 weeks were used. The animals were anesthetized with intraperitoneal pentobarbital sodium 50 mg/kg. L(5) spinal nerve was ligated between DRG and sciatic nerve and cut distal to the ligature. The animals were decapitated at Day 14 post-operation. L(5) (SNL-L(5) group) and L(4) DRGs (SNL-L(4) group) were respectively isolated and the ganglionic neurons enzymatically dissociated. The control group of rats was not operated. The lumbar DRG neurons of normal rats were treated similarly. The HVA-Ca(2+) current was recorded by the technique of whole cell patch clamp.
  
  
  RESULTS
  Compared with the SNL-L(4) group [(16.0 ± 1.9)%, (26.9 ± 2.0)%, (27.4 ± 2.3)%] and the control group, gabapentin inhibited the peak calcium current highlier at 10, 100 and 300 µmol/L in the SNL-L(5) group [(18.5 ± 1.7)%, (32.0 ± 2.6)%, (32.7 ± 2.8)%] (P < 0.05). The steady-state inactivation curves shifted to more hyperpolarized potentials in the SNL-L(5) group. The N-type relative contribution to the gabapentin-sensitive HVA-Ca(2+) current was markedly elevated in the SNL-L(5) group compared with that in other two groups (P < 0.05).
  
  
  CONCLUSIONS
  Gabapentin enhances the inhibition of HVA-Ca(2+) current in injured DRG neurons following spinal nerve ligation in rats. The alteration in the activation of electrophysiological properties and the increase of N-type relative contribution to the total HVA-Ca(2+) current may be involved in the mechanism.
authors.affiliation: Department of Anesthesiology, Nanjing General Hospital of Nanjing Military Command, Nanjing, China.
authors.forename: Xiao-di
authors.initials: XD
authors.lastname: Sun
authors.forename: Min-min
authors.initials: MM
authors.lastname: Zhu
authors.forename: Xiao-dong
authors.initials: XD
authors.lastname: Chen
authors.forename: Dan
authors.initials: D
authors.lastname: Li
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wang
authors.forename: Hang
authors.initials: H
authors.lastname: Xiao
authors.forename: Jian-guo
authors.initials: JG
authors.lastname: Xu
authors.forename: Man-lin
authors.initials: ML
authors.lastname: Duan
mesh_terms: D000588:Amines / Q000494:pharmacology*; D000818:Animals; D020864:Calcium Channels, N-Type / Q000187:drug effects* / Q000502:physiology; D002478:Cells, Cultured; D003509:Cyclohexanecarboxylic Acids / Q000494:pharmacology*; D000077206:Gabapentin; D005727:Ganglia, Spinal / Q000187:drug effects* / Q000502:physiology; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D018408:Patch-Clamp Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
chemical_list: D000588:Amines; D020864:Calcium Channels, N-Type; D003509:Cyclohexanecarboxylic Acids; D005680:gamma-Aminobutyric Acid; D000077206:Gabapentin