Dual effects of pentobarbital on rat sacral dorsal commissural neurons in vitro.
OBJECTIVE
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.


CONCLUSIONS
PB had dual effects on SDCN, facilitated GABAA receptor-mediated currents and at higher concentrations induced Cl- influx itself.
Pang
Z P
ZP
Department of Anatomy, K K Leung, Brain Research Centre, Fourth Military Medical University, Xi-an, China.
Xu
T L
TL
Hu
G Y
GY
Li
J S
JS
D000759:Adjuvants, Anesthesia / Q000494:pharmacology*; D000818:Animals; D000831:Animals, Newborn; D018118:Chloride Channels / Q000187:drug effects*; D018757:GABA Modulators / Q000494:pharmacology; D066298:In Vitro Techniques; D009474:Neurons / Q000502:physiology; D018408:Patch-Clamp Techniques; D010424:Pentobarbital / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000502:physiology*; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
D000759:Adjuvants, Anesthesia; D018118:Chloride Channels; D018757:GABA Modulators; D005680:gamma-Aminobutyric Acid; D010424:Pentobarbital