局部应用胰岛素对小鼠创面髓过氧化物酶及丙二醛的影响

Effect of topical application of insulin on wound myeloperoxidase and malondialdehyde level in mice excision wounds

目的观察小鼠创面局部应用小剂量胰岛素对创面髓过氧化物酶、丙二醛的影响,从对炎症调控角度探索胰岛素促进创面愈合的机制。方法 48只C57BL/6J小鼠背部两侧对称部位造成两个全层皮肤缺损创面。按自身对照方法,每只小鼠背部两个创面随机分为胰岛素组和对照组。伤后即刻及伤后每24h,胰岛素组创面局部应用0.03U胰岛素(20μl生理盐水配置),对照组应用20μl生理盐水。随机选取12只小鼠用药至创面愈合,观察愈合时间和速率。余36只小鼠于伤后1、2、3d分别处死12只后取创面及创周5mm组织,免疫印记化学发光法检测创面髓过氧化物酶(MPO)、生化方法检测丙二醛(MDA)含量。结果胰岛素组创面愈合时间显著短于对照组(P<0.05);伤后第5、7天胰岛素组的创面愈合百分率显著高于对照组(P<0.05)。伤后第2、3天胰岛素组和对照组创面MPO含量分别为1.52±0.37、1.95±0.53和1.2±049、1.25±0.39,两组比较差异有统计学意义(P<0.05)。胰岛素组与对照组创面MDA含量在伤后1、2、3d比较,差异均无统计学意义。结论胰岛素在增强创面杀菌功能的同时减轻细胞损伤,可能是胰岛素促进创面愈合的机制之一。

Objective To observe the effects of topical application of low dose of insulin on myeloperoxidase （MPO） and malondialdehyde （MDA） level of wound, and to explore the mechanism of insulin accelerated wound healing from the view of regulating inflammatory response. Methods It was a self-control trail. Two 5 mm diameter exeisional wounds were made on the back of the C57BL/6J mice. The two wounds on each mouse were randomized to insulin group and control group, respectively treated with 0. 03 U insulin （ diluted in 20μl saline） and 20 μl saline immediately and every 24 hours. Wounds tissues along with 5 mm adjacent normal skin were collected at first three consecutive days after wounding. Healing time and process were recorded and monitored in 12 mice. Wounds MPO levels were detected by Western-blotting, wounds MDA level were determined by biochemical assay. Results The healing time of insulin group was significantly shorter than control group （ P 〈 0.05 ）. Accordingly, a higher healing rate was found in insulin group compared with healing rate in control group （ P 〈 0.05 ）. Densitometric analysis showed that optical density of MPO level in insulin group at day 2 and day 3 after wounding was 1.52 ±0.37 and 1.95 ±0.53, which were obviously higher than that of control group （ 1.2 ±049 and 1.25 ±0.39 ）. No significant differences of MDA level at the first three days after wounding were found between the two groups. Conclusions Insulin stimulates polymorphonuclear cell function while protects cells from the damage of oxygen free radical. The effect of insulin might be involved in insulin induced accelerated healing.