异丙酚对大鼠化学性内脏痛的抗伤害性刺激作用

Antinociceptive Effect of Propofol on Chemical Visceral Pain in Rats

目的 观察异丙酚对内脏痛大鼠行为的影响及其持续时间。方法 以腹腔注射醋酸引起的大鼠扭体反应作为内脏痛的实验模型。雄性SD大鼠 50只随机均分为脂肪乳剂 1ml/kg、异丙酚 5mg/kg、异丙酚 10mg/kg、异丙酚 2 0mg/kg、硫喷妥钠 5mg/kg共 5组。注药后即放入玻璃观察箱 ,计数 3 0min内出现的扭体次数。 结果 大鼠在腹腔注射 2 %醋酸 3ml/kg后 ,均出现扭体反应 ,脂肪乳剂对照组 3 0min内扭体平均次数为 2 4.1± 5.7;异丙酚 10mg/kg、2 0mg/kg腹腔注射后 3 0min内大鼠扭体次数分别为 16.7± 2 .9、10 .8± 4.6,两组之间有显著性差异 (P <0 .0 1) ,与脂肪乳剂组间也均有差异 (P <0 .0 5,P <0 .0 1) ;硫喷妥钠 5mg/kg腹腔注射后 3 0min之内大鼠扭体次数为 3 1.6± 5.0 ,与脂肪乳剂组及异丙酚 10mg/kg组比较有显著性差异 (P <0 .0 1)。 结论 亚睡眠剂量异丙酚能以剂量依赖方式抑制醋酸所致大鼠内脏伤害性刺激的感受 ,其持续时间为 2 0min ;等效剂量的硫喷妥钠有痛觉过敏作用 ;

Objective To investigate the effect and duration of subhypnotic propofol on chemical visceral pain in rats. Methods Chemical visceral pain model was established in male SD rats weighing 180-240g ( n =50) by intraperitoneal injection (ip) of 2% acetic-acid (3 ml/kg). Rats were randomly divided into emulsion (1 ml/kg) control group (group C, n=10), propofol 5mg/kg group (group P5, n=10), propofol 10mg/kg group (group P10, n=10), propofol 20 mg/kg group (group P20, n=10) and thiopental sodium 5mg/kg group (group T5, n=10). All drugs were administered ip 1 min after acetic-acid ip. The animals were then placed into an individual observation chamber to measure the writhing response. The numbers of writhes were counted every 5 min in duration of 30 min. Results All rats writhed after acetic-acid ip. The number of writhe was 24.1±5.7 in group C. Propofol at doses of 10 mg/kg and 20 mg/kg significantly ( P <0.05 and P <0.01) reduced the number of writhe with average numbers of 16.7±2.9 and 10.8±4.6 respectively. Propofol at dose of 5 mg/kg had no antinociceptive effect compared to that of emulsion. There were significant differences in the number of writhes among the groups of different doses of propofol. The mean writhing number in group T5 was 31.6±5.0, which was significantly ( P <0.01) higher than that in group C. Conclusions These results suggest that propofol at subhypnotic doses have an antinociceptive effect on chemical visceral pain induced by aceptic-acid ip. The antinociception of propofol was dose-dependent with duration of 15-20min. Thiopental sodium at equivalent dose of propofol 10 mg/kg has no antinociceptive effect, but a hyperalgesic effect.