Atosiban及纳洛酮对缩宫素镇痛作用的影响

Role of atosiban and naloxone in analgesic effects of oxytocin

目的观察atosiban和纳洛酮对缩宫素(oxytocin,OT)中枢痛觉调制作用的影响。方法雄性SD大鼠随机分为鞘内注射组和侧脑室注射组2个大组。每个大组又分为7个剂量组:生理盐水+OT组(C组);atosiban+OT高、中、低剂量组;纳洛酮+OT高、中、低剂量组。各组大鼠在切割给药后的10 min、30 min、1 h、3 h、6 h、12 h、24 h进行机械性痛阈测定,检测其变化情况。结果鞘内和侧脑室内预注射atosiban大鼠在注射OT后各时间点痛阈均低于C组(P<0.05);预注射纳洛酮大鼠注射中、低剂量OT后痛阈较C组大鼠降低(P<0.05);预注射纳洛酮大鼠注射0.25 nmol OT后其痛阈与C组差异无统计学意义(P>0.05)。结论鞘内和侧脑室内预注射atosiban可以阻断OT的镇痛作用,纳洛酮部分阻断OT镇痛效应。

Objective To study the role of atosiban and naloxone in the analgesic effects of oxytocin （OT）. Methods Male SD rats were divided randomly into 2 groups, i. th group and i. c. v group. And both groups subdivided as below ： N. S ＋ OT （ control group, C） ;atosiban ＋ OT low, medium and high dose groups;naloxone ＋ OT low, medium and high dose groups. And the mechanical pain threshold was tested 10 min,30 min,1 h,3 h,6 h, 12 h,24 h after incision in all of the rats. Results I. th and i. c. v administration of atosiban could thoroughly inhibit the analgesia effect of OT（ P 〈 0.05 ） ; compared with control group, the pain threshold of rats with naloxone only decreased after low and medium doses of OT（ P 〈 0.05 ） ; the pain threshold had no significant differences between the high dose OT treated rats and the control group（ P 〉 0.05 ）. Conclusions The analgesic effect of OT can be totally inhibited by i. t. h or i. e. v atosiban, but partly depressed by naloxone.