THE RELATIONSHIP BETWEEN ANALGESIC EFFECT OF KETAMINE AND OPIOID RECEPTOR

[Objective]To discuss the relationship between analgesic effects of ketamine and opioid receptor.[Methods]120 mice were randomly divided into two groups:hot-plate group and writhing test group,and each group was further divided into control group and ketamine group with 10 mice in each subgroup. The control group was treated with intraperitoneal injection of normal saline and different concentrations of naloxone respectively. The ketamine group was treated with intraperitoneal injection of 20 mg/kg ketamine,5 minutes later,the mice were respectively injected with normal saline and different concentrations of naloxone. The effects of intraperitoneal injection of naloxone on the HPPT(pain threshold in hot plate test)and writhing times were observed.[Results]The intraperitoneal injection of naloxone had no significant effect on the writhing times of the mice injected with ketamine(P﹥0.01),but could decrease the HPPT(P﹤0.01).[Conclusions]The analgesic effect of ketamine to thermal stimulation has effect on opioid receptor,while the analgesic effect to chemical stimulation has little effect on opioid receptor.