烧伤后红细胞膜粘弹性改变对心肌局部血流量的影响

The influence of the change in postburn erythrocyte membrane viscoelasticity on the regional myocardial blood flow

目的 观察烧伤后红细胞膜粘弹性的动态变化特征及其对心肌局部血流量的影响。 方法 大鼠 30 %TBSAⅢ度烧伤模型 ,采用微管吸吮法测定伤前 ,伤后 1、3、6、12、2 4、48h红细胞膜的弹性模量和粘性系数等力学参数。同时利用氢清除法测定心肌局部血流量。 结果 伤后 3h红细胞膜粘弹性显著升高 ,6h达高峰 ,以后逐渐下降至 2 4h接近正常值。伤后 1h ,心肌局部血流量显著降低 ,6h达最低点 ,以后逐渐增高 ,至 48h接近正常值。两者呈显著负相关。 结论 烧伤后红细胞膜变形能力下降 ,此结果导致心肌局部血流量降低 。

Objective To explore the characteristics of the dynamic change in postburn erythrocyte membrane viscoelasticity and its influence on the regional myocardial blood flow. Methods Wistar rats inflicted with 30% TBSA Ⅲ degree scalding on the back were employed as the model. The mechanical indices of erythrocytic membrane,such as elastic modulus and the coefficient of viscosity,were determined with micropipe sucking methods at preburn and 1,3,6,12,24 and 48 postburn hours (PBHs). The regional myocardial blood flow was simultaneously monitored with hydrogen clearance methods. Results The erythrocyt membrane viscoelasticity increased sharply at 3 PBH, reached the peak level at 6 PBH and decreased gradually thereafter to near normal level at 24 PBH. The regional myocardial blood flow decreased obviously at 1 PBH, it reached the lowest level at 6 PBH and bounced back to near normal level at 48 PBHs. The change in the viscoelasticity was significantly and negatively correlated to that of the regional myocardial blood flow. Conclusion The deformability of postburn erythrocyte membrane decreased, leading to the decrease in the regional myocardial blood flow. This might be one of the important reasons of postburn myocardial injury.