Dual effects of pentobarbital on rat sacral dorsal commissural neurons in vitro
Abstract
AIM: To study the effects of pentobarbital (PB) on acutely dissociated rat sacral dorsal commissural neurons (SDCN).
METHODS: Nystatin-perforated patch clamp recording was used.
RESULTS: (1) At a holding potential of -40 mV, PB induced inward Cl- current (IPB) in a concentration-dependent manner with a EC50 (95% confidence limits) of 416 (385-477) mumol.L-1 and a Hill coefficient of 1.08. (2) Picrotoxin reversibly blocked IPB. (3) The reversal potential of IPB was close to the Cl- equilibrium potential. (4) PB enhanced GABA-induced Cl- influx (IGABA). In the presence of PB 30 mumol.L-1, the EC50 (95% confidence limits) of IGABA decreased from 6.9 (5.4-8.4) mumol.L-1 to 3.5 (2.9-4.1) mumol.L-1.
CONCLUSION: PB had dual effects on SDCN, facilitated GABAA receptor-mediated currents and at higher concentrations induced Cl- influx itself.
Keywords:
METHODS: Nystatin-perforated patch clamp recording was used.
RESULTS: (1) At a holding potential of -40 mV, PB induced inward Cl- current (IPB) in a concentration-dependent manner with a EC50 (95% confidence limits) of 416 (385-477) mumol.L-1 and a Hill coefficient of 1.08. (2) Picrotoxin reversibly blocked IPB. (3) The reversal potential of IPB was close to the Cl- equilibrium potential. (4) PB enhanced GABA-induced Cl- influx (IGABA). In the presence of PB 30 mumol.L-1, the EC50 (95% confidence limits) of IGABA decreased from 6.9 (5.4-8.4) mumol.L-1 to 3.5 (2.9-4.1) mumol.L-1.
CONCLUSION: PB had dual effects on SDCN, facilitated GABAA receptor-mediated currents and at higher concentrations induced Cl- influx itself.