The Relationship Between Analgesia Effect of Ketamine and Spinal NMDA Receptors

Aim To explore the relationship between the analgesic effect of Ketamine and NMDA receptors in order to improve the clinical anesthesic effect of Ketamine.Methods 160 mice were randomly divided into 2 groups(hot-plategroup and writhing test group).Each group contained 2 medium groups(comparison group and Ketamine group).Moreover,each medium group contained 4 small groups of 10 mice.The comparison group was intrathecally injected with ACSF or different concentrations of NMDA;the Ketamine group was also intrathecally injec ted with the same substance 5min after injection of Ketamine The effect of NMDA on pain threshold in hot-plate and writhing times in the mice injected with ketamine was observed.Results NMDA didn't affect the pain threshold and the writhing times in hot-plate,but could increase the writhing times(P0.05)and shorten the pain threshold of the mice injected with Ketamine.Conclusion NMDA intrathecal injection can resist the analgesic effect of Ketamine,and spinal NMDA receptors can mediate the effect of Ketamine.