冰片外用对大鼠后肢穿刺伤急性疼痛的抑制作用

目的研究冰片外用对大鼠外伤引起的急性疼痛的抑制作用及机制。方法将45只SD大鼠随机分为假手术组、手术组及外用冰片组3组,假手术组仅对手术部位进行皮肤脱毛,建立手术组及外用冰片组大鼠后肢穿刺伤疼痛模型,外用冰片组术后创面外用冰片粉末300 mg。观察外用冰片组和手术组术后不同时间点继发机械痛阈、继发热痛阈水平和脊髓背角Fos蛋白阳性细胞数量（FPIN）的差异。结果假手术组在整个实验过程中痛阈变化与基础值比较差异无统计学意义（P〉0.05）。外用冰片组术后继发机械痛阈、继发热痛阈值均高于手术组,FPIN（22.6±6.7）低于手术组（36.2±5.8）,差异均有统计学意义（P〈0.05）。结论冰片外用于损伤部位,通过抑制损伤处伤害性感受器的传入信号对外伤后引发的急性疼痛产生抑制作用。

External Application of Borneol to Inhibit Acute Pain after Injury in Rats

Objective To study external application and mechanism of borneol to inhibit the acute pain after trauma in rats.Methods 45 SD rats were randomly divided into 3 groups,which were sham operation group,surgery group and borneol group respectively.Rats in sham operation group only received epilation on their surgical site,while a model of hind limb pain after penetrating injury in the surgical group and borneol group was established,and the borneol group received borneol topical powder 300 mg on wounded part after surgery.The difference of the secondary mechanical pain threshold,secondary thermal pain threshold and Fos protein immunoreactive cell number（FPIN） of spinal dorsal horn in both borneol group and surgery group were observed.Results Changes of pain threshold from baseline showed no significant difference in the sham group during the experiment（P 0.05）.Both the secondary mechanical pain threshold and secondary thermal pain threshold in borneol group were higher than that in surgery group at each time point,FPIN was（22.6±6.7）in borneol group,lower than that in surgery group（36.2±5.8）,and the differences were statistically significant（P0.05）.Conclusion Inhibiting the afferent signal sent out by local nociceptors,the borneol applied to the wounded part can reduce acute pains.