锌_7-金属硫蛋白对深Ⅱ度烧伤创面脂质过氧化反应的影响

Effect of Zn_7-metallothionein on lipid peroxidation of rats following deep Ⅱ skin burns

背景:研究表明锌-金属硫蛋白具有明显的清除氧自由基和保护生物大分子的功能。目的:观察锌7-金属硫蛋白对大鼠深Ⅱ度烧伤创面脂质过氧化反应的影响及在创面愈合中的作用。设计、时间及地点:随机对照动物实验,于2008-10/2009-01在解放军第三军医大学大坪医院野战外科研究所第二研究室完成。材料:健康雄性Wistar大鼠78只,随机分为2组,锌7-金属硫蛋白保护组、生理盐水组各36只,各组观察时相点为伤后12,24,48h及7,14,21d,每时相点6只。方法:将大鼠背部置于98℃水中8s,造成大鼠背部15%的深Ⅱ度烫伤创面。2组均于伤后即刻给药,锌7-金属硫蛋白保护组与生理盐水组分别外敷单层纱布浸润的浓度为1×10-5mol/L的锌7-金属硫蛋白以及等渗盐水,第1天每4h换药1次,第2,3天每8h换药1次,此后每日换药1次,直至创面愈合。主要观察指标:伤后7d开始采用硬纸片质量间接法测创面愈合率。伤后各时相点取创面组织标本(创面已愈合则取瘢痕组织),分别测羟脯氨酸、丙二醛含量和超氧化物歧化酶活性。结果:伤后7,14,18,21d锌7-金属硫蛋白组创面愈合率高于生理盐水组(P<0.05);且锌7-金属硫蛋白组伤后48h,7d,14d,超氧化物歧化酶活性降低程度和丙二醛含量升高程度与生理盐水组比较差异有显著性意义(P<0.05);锌7-金属硫蛋白组在伤后48h,7d羟脯氨酸含量减少程度显著低于生理盐水组(P<0.05),且在14d时含量已接近正常水平。结论:锌7-金属硫蛋白对大鼠深Ⅱ度烧伤创面有促愈合作用,其促愈机制与使用锌7-金属硫蛋白后创面脂质过氧化反应程度减轻有关。

BACKGROUND： Zn7-metallothionein （ZnT-MT） can remove oxygen-derived free radicals and protect biomacromolecule. OBJECTIVE： To study the effects of ZnT-MT on lipid peroxidation and wound surface healing of rats with deep grade Ⅱ skin burns. DESIGN, TIME AND SETTING： A randomized controlled animal experiment was performed at the Second Laboratory of Battle Surgery Institute, Daping Hospital, the Third Military Medical University of Chinese PLA between October 2008 and January 2009. MATERIALS： A total of 78 healthy male Wistar rats were randomly divided into ZnT-MT group and saline group, with 36 rats per group. Then, the observation was performed at six different time points, including 12, 24, 48 hours, 7, 14, and 21 days, with 6 rats at each time point. METHODS： Back of rats was stored in water at 98 ℃ for 8 s to establish 15% deep grade Ⅱ burning models. ZnF-MT at the concentration of 1 × 10^-5 mol/L was immediately administrated in the Zn7-MT group, while saline was used in the saline group. The-bandage was changed every 4 hours on the first day, every 8 hours on the second and third days, and then every day till the wound surface was healed. MAIN OUTCOME MEASURES： Healing rate was indirectly measured using hard slip at day 7 post-burning; the contents of hydroxyproline （HYP） and malondialdehyde （MDA） and activity of superoxide dismutase （SOD） were detected at each time point. RESULTS： The wound healing rate in the ZnF-MT group was significantly higher than saline group （P 〈 0.05） at 7, 14, 18, and 21 days after burning. While, at 48 hours, 7 days and 14 days after burning, the SOD activity was decreased but MDA content was increased in the Zn7-MT group, which was significant difference compared to saline group （P 〈 0.05）. At 48 hours and 7 days after burning, the HYP content was decreased in the Zn7-MT group, but it was still higher than saline group （P 〈 0.05）; moreover, the HYP content reached the normal level at day 14 post-burning. CONCLUSION： Zn7-MT can promote the wound healing of deep grade Ⅱskin burns significantly, which is related to that Zn7-MT can relieve lipid peroxidation of the burned wound.