[Effect of ketamine on high-voltage-activated calcium currents in rat hippocampal neurons].
OBJECTIVE
To investigate the effect of ketamine on the high-voltage-activated calcium currents (ICa(HVA)) in rat hippocampal neurons.


METHODS
Neurons were cultured from Wistar rat hippocampus. ICa(HVA) was recorded using whole-cell patch clamp technique. After application with ketamine at different concentrations (10, 30, 100, 300, and 1000 μmol/L), the effect of ketamine on ICa(HVA) was evaluated.


RESULTS
ICa(HVA) was inhibited by ketamine in a concentration-dependent manner. Ketamine at 10 μmol/L showed no effect on ICa(HVA). Four concentrations of ketamine (30, 100, 300,and 1000 μmol/L) reduced the peak ICa(HVA) currents by (17.5 ∓ 4.5)%, (25.5 ∓ 6.9)%, (38.5 ∓ 4.1)%, and (42.3 ∓ 4.6)% respectively,with a mean half maximal inhibitory concentration of 68.2 μmol/L and Hill coefficient of 0.47. The maximal activation membrane potential was shifted to (5.3 ∓ 0.8) from (5.4 ∓ 0.9). The half maximal activation membrane potential of inactivation curve was shifted from(-26.7 ∓ 3.9) mV to(-32.8 ∓ 4.2) mV.


CONCLUSIONS
Ketamine can remarkably inhibit calcium currents in the central neurons,which may explain at least partly the action of ketamine on central nervous system.
Tan
Hong-Yu
HY
Department of Anesthesiology, PUMC Hospital, CAMS and PUMC, Beijing 100730, China.
Ma
Shi-Ping
SP
Ye
Tie-Hu
TH
Wang
Xiao-Liang
XL
D000818:Animals; D015220:Calcium Channels / Q000187:drug effects* / Q000502:physiology; D002478:Cells, Cultured; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D007649:Ketamine / Q000494:pharmacology*; D008564:Membrane Potentials / Q000187:drug effects; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar
D015220:Calcium Channels; D007649:Ketamine