锌-金属硫蛋白对烫伤大鼠迟延复苏红细胞膜损伤的保护作用

Protective effects of Zn-metallothionein on erythrocyte membrane of rats with severe scalding after delayed resuscitation

目的 探讨锌 金属硫蛋白 (Zn MT)对抗严重烫伤动物延迟复苏后出现的氧化应激效应。 方法 采用大鼠 30 %总体表面积Ⅲ度烫伤模型 ,将 2 7只大鼠平均分成正常对照组、延迟复苏组、及Zn MT保护组。烫伤 4h后在保护组动物所补液体中 ,加入Zn MT (1× 10 -5mol/L)。伤后 2 4h取血 ,用电子自旋共振标记物马来酰亚胺标记红细胞膜 ,检测红细胞膜蛋白构象。取血清 ,加入黄嘌呤 ,黄嘌呤氧化酶及自旋共振自旋捕集剂二甲基吡啶氮氧化物以判断血清中超氧化物歧化酶 (SOD)含量变化。 结果 各组大鼠红细胞膜蛋白强弱固定化比值分别为 0 35 2± 0 0 4 3、0 4 0 9± 0 0 2 7及0 386± 0 0 6 2 ,旋转相关时间 (s)分别为 1 30 0± 0 2 10、1 5 76± 0 190及 1 381± 0 2 10 ,与正常对照组相比 ,延迟复苏组大鼠红细胞膜蛋白构象明显改变 ,膜蛋白运动速度明显减慢 ,给予Zn MT后 ,膜蛋白构象改变及膜蛋白运动速度降低的程度明显减轻。各组大鼠血清中SOD相对含量分别为 73 2 %±1 4 %、4 8 8%± 3 8%、6 6 8%± 3 2 % ,与正常对照组相比 ,延迟复苏组动物血清SOD含量明显降低 ,而Zn MT治疗组动物血清SOD含量降低的程度明显减少 ,说明烫伤延迟复苏组动物体内生成过多的氧自由基能被Zn MT清除。 结论 Zn

Objective To study the antagonism of Zn metallothionein (Zn MT) to oxidative stress of rats with severe scalding after delayed resuscitation. Methods 27 Wistar rats were randomly divided into three groups: normal control; burn with delayed fluid resuscitation group; and Zn MT protected group. The rats were scalded with 30% total body surface area (TBSA) third degree burn. Four hours after injury, they were resuscitated, but Zn MT(1×10 -5 mol/L) was given in the third group rats. 24 hours after they were scalded, blood was taken, RBCs were separated and labeled with electron spin resonance (ESR) spin label 3 maleimido proxyl to detect membrane protein conformation. The serum was collected and added into the reaction system of xanthine, xanthine oxidase and ESR spin trap 5,5 dimethylpyroline N oxide to assay the levels of superoxide dismutase (SOD) by ESR. Results The ratios of strong solidity and weak solidity of RBC membrane proteins in the three groups were 0 352±0 043, 0 409±0 027, and 0 386±0 062 respectively, and the revolved times of membrane proteins were 1 300±0 210, 1 576±0 190 and 1 381±0 210 seconds respectively. Compared to the first group, the membrane protein conformation in the second group was changed remarkably, and the speed of membrane protein movement decreased significantly. However, those changes were alleviated obviously by Zn MT. The SOD levels in serum of the three groups rats were 73 2%±1 4%, 48 8%±3 8% and 66 8%±3 2% respectively. Compared to the normal control group, the SOD levels in serum of the second group decreased obviously. However, an excess of oxygen free radicals produced after injury could be scavenged by Zn MT. Conclusion RBC membrane proteins of rats with severe scalding after delayed resuscitation were injured by oxygen free radicals produced after injury, and Zn MT could alleviate this injury.