Abstract: Objective To investigate the effect of ketamine on the low-voltage-activated calcium currents [ICa(LVA)]in rat hippocampal neurons. Methods Hippocampal neurons were isolated from Wistar rats and cultured. ICa(LVA) was recorded using whole-cell patch clamp technique. Different concentrations of ketamine were added to the culture. The effect of ketamine on ICa(LVA) was evaluated. Results ICa(LVA) was inhibited by ketamine in a concentration-dependent manner. Ketamine at the concentration of 10 μmol /L had no effect on ICa(LVA). Ketamine at the concentration of 30, 100, 300 μmol/L and 1 000 μmol/L reduced peak ICa(LVA) by(12±4)%, (19±4)%, (32±3)%, (31±2)% respectively. The IC50 was at 110 μmol/L and Hill coefficient was 0.14. V1/2 of activation curve was shifted from (-8±0) mV to (-10±2) mV. The V1/2 of inactivation curve was shifted from (-42±6) mV to (-48±6) mV. Conclusions Ketamine produces significant inhibition of ICa(LVA) in hippocampal neurons which may partly explain the action of ketamine on central nervous system.
|