Intrathecal diazepam suppresses nociceptive reflexes and potentiates electroacupuncture effects in pentobarbital-anesthetized rats.

Using noxious heat-evoked tail flick in rats anesthetized with pentobarbital infusion, we studied the effects of diazepam applied intrathecally. This drug caused a marked suppression of nociceptive reflexes in a dose-dependent manner. In addition, a small non-suppressive dose of diazepam potentiated electroacupuncture effects. These results are discussed in terms of gamma-aminobutyric acid (GABA) since it is known that diazepam enhances binding of GABA to its receptor and hence potentiates inhibitory effects of GABA in the spinal cord. The possible synergism of diazepam and pentobarbital is also discussed.