静脉注射士的宁对氯胺酮镇痛作用的影响

EFFECTS OF INTRAVENOUS INJECTION OF STRYCHNINE ON ANALGESIC EFFECT OF KETAMINE

[目的]探讨甘氨酸受体与氯胺酮镇痛作用的关系。[方法]在热板、扭体法实验中,观察不同剂量的士的宁对氯胺酮小鼠痛阈及扭体次数的影响。[结果]腹腔注射氯胺酮10mg/kg对小鼠热板法痛阈无影响(P﹥0.05),20、40mg/kg可使小鼠痛阈增加(P﹤0.05);腹腔注射氯胺酮10mg/kg对小鼠扭体次数无影响(P﹥0.05),20、40mg/kg均可使小鼠扭体次数减少﹙P﹤0.05);静脉注射士的宁0.25μg对腹腔注射氯胺酮(40mg/kg)小鼠痛阈无影响﹙P﹥0.05);0.5、0.75、1.0μg可使氯胺酮小鼠痛阈减少﹙P﹤0.05);士的宁(0.25、0.5、0.75、1.0μg)静脉注射对氯胺酮(40mg/kg)小鼠的扭体次数无影响﹙P﹥0.05)。[结论]氯胺酮在热板法和扭体法中产生的镇痛作用是不相同的,提示前者可能涉及甘氨酸受体,而后者与甘氨酸受体关系不大。

[Objective] To discuss the relationship between glycine receptor and analgesic effect of ketamine. [Methods] The changes of pain threshold in hot-plate test and writhing test were examined, and the effects of intravenous injection of strychnine at different doses on the rats injected with ketamine were observed. [ Results] Intraperitoneal injection of Ket （ 10 mg/kg） had no effect on pain threshold in hot-plate test （P〉 0.05）, but intraperitoneal injection of Ket （20 mg/kg or 40 mg/ kg） increased the HPPT of the rats （P 〈 0.05） ; intraperitoneal injection of Ket （10 mg/kg） had no effect on writhing times （P 〉 0.05）, whereas intraperitoneal injection of Ket （20 mg/kg or 40 mg/kg） decreased writhing times （P〈 0.05） . Intravenous injection of Strychnine （0.25μg） had no effect on the HPPT of the rats injected with Ket （40 mg/kg） （P 〉 0.05）, while intravenous injection of Strychnine （0.5. 0.75, 1.0 μg） decreased the HPPT （P〈 0.05）; and intravenous injection of Strychnine （0.25, 0.5, 0.75. 1.0μg） had no effect on writhing times （P 〉 0.05）. [Conclusions] Analgesic effect of ketamine in hotplate test and writhing test are different, which indicates that the former may involve glycine receptor while the later has little relation with glycine receptor.