盐酸羟考酮超前镇痛对福尔马林致痛模型大鼠疼痛行为和大鼠血液NO及P物质浓度的影响

Effect of oxycodone hydrochloride in preemptive analgesia on pain behaviors induced by formalin and concentration of NO and substance P in blood in rat pain model

通过刺激前应用盐酸羟考酮观察福尔马林致痛模型大鼠的镇痛效果和血液中NO及P物质浓度的变化,探讨盐酸羟考酮超前镇痛的作用机制。选取健康成年Wistar大鼠32只,雌雄各半,体质量250~300 g,随机分为4组(每组8只),正常空白对照组(A组)腹腔注射0.9%氯化钠溶液2 m L;福尔马林模型组(B组)用微量注射器抽取5%福尔马林100μL注入大鼠右侧后爪掌心皮下致痛;盐酸羟考酮致痛前给药组(C组),福尔马林致痛前30 min腹腔注射盐酸羟考酮0.2 mg·kg-1;盐酸羟考酮致痛后给药组(D组),福尔马林致痛后30 min腹腔注射盐酸羟考酮0.2 mg·kg-1。致痛后1,10,20,30,45,60,90 min观察动物疼痛行为改变,以累积疼痛评分评定疼痛行为。致痛后90 min用水合氯醛麻醉大鼠,心脏采血3 m L测定其NO及P物质浓度的变化。根据大鼠行为学改变及疼痛评分的结果显示,本试验造模成功。疼痛评分值:致痛后10 min,C组比B组明显减小(P<0.05);60~90 min,C、D组与B组比较明显减小(P<0.05)。血液标本中NO浓度C、D组与B组比较明显降低,差异有统计学意义(P<0.01),C组和D组比较,差异也有统计学意义(P<0.05);血液中P物质浓度C、D组与B组比较明显降低,差异也有统计学意义(P<0.001),C组和D组比较,差异也有统计学意义(P<0.05)。结果表明,大鼠福尔马林致痛模型致痛前和致痛后30 min腹腔注射盐酸羟考酮均有明显的镇痛作用,镇痛效果与降低血液中NO及P物质的浓度相关,二者比较,致痛前30min给药即超前镇痛作用更显著。

In this research,oxycodone hydrochloride was applied before stimulation to observe the town carbuncle effect of formalin induced pain model rats and the concentration changes of NO and substance P,which help to discuss the mechanism of action of oxycodone hydrochloride advance town carbuncle. 32 healthy adult Wistar rats( male and female,body quality 250-300 g) were randomly divided into 4 groups( n = 8),normal control group( group A) with intraperitoneal injection of 0. 9% sodium chloride solution2 m L; formalin model group( group B) with claw palm subcutaneous induced pain on the right side of rats with microinjector contained 5% formalin 100 μL; oxycodone hydrochloride induced before drug group( group C) with formalin 0. 2 mg·kg- 1intraperitoneal injection of oxycodone hydrochloride 30 min before injected formalin; oxycodone hydrochloride induced pain after drug group( D group) with hydrochloride 0.2 mg·kg- 1intraperitoneal injection of oxycodone 30 min after formalin injection. The changes of the animal pain behavior were observed when the pain induced after 1,10,20,30,45,60,90 min,with cumulative pain score to evaluate the pain behavior. 90 min after the pain induced,rats were anesthetized with chloral hydrate,and 3 m L of heart blood sample was collected to determine the concentration changes of the NO and P substance. The studies of rat behavior change and pain score results showed that the experimental model has been successes made. 10 min after induced pain,the pain score value in C group decreased significantly than that in B group( P < 0. 05); 60-90 min after the induced pain,the pain score value between group C,D decreased obviously compared to that of group B( P < 0. 05); NO concentrations of blood samples of C,D group were decreased greatly compared with B group,the difference was statistically significant( P < 0.01),and the differences between C and D group were also statistically significant( P < 0. 05); substance P concentrations of C,D group decreased greatly compared with B group,the difference was statistically significant( P < 0. 001),and the differences between C and D group were also statistically significant( P <0. 05). The results showed that there were obvious analgesic effect of oxycodone hydrochloride in formalin rat pain model induced by intraperitoneal injection 30 min before and after formalin induced pain,and the analgesic effect is associated with the decreasing concentration of NO and P substances in the blood,and with the comparision of the administration after 30 min,30 min before the pain induced,which is a more preemptive analgesia has a better effect.