应用自旋标记-顺磁共振技术观察烧伤早期心肌细胞膜蛋白变化

Early cardiac myocyte membrane changes in severely burned rats: a spin labelingESR study

目的：研究严重烧伤大鼠早期心肌细胞膜蛋白结构和运动的变化。方法：用３－甲基马来酰亚胺氮氧自由基（３ＭＰ）标记膜蛋白巯基，利用自旋标记－顺磁共振技术，观察膜蛋白旋转相关时间（τｃ）及强固定化与弱固定化组分谱线高度比值（ｈｓ／ｈｗ）的变化。结果：伤后２和６ｈ膜蛋白ｈｓ／ｈｗ显著增大，伤后１～１２ｈ膜蛋白旋转相关时间τｃ显著增大。结论：严重烧伤后早期即出现心肌细胞膜蛋白结构和功能的变化，表现为膜蛋白构象改变，膜蛋白运动受限。这些变化可以直接影响细胞膜蛋白的功能。

Objective: To demonstrate the mechanism of early cardiac myocyte membrane damage at molecular level in severely burned rats. Methods: SD rats were randomly divided into shamburn and burn groups. A 30%TBSA burn was created in burn group. Hearts were obtained at different time postburn. Cardiac myocytes isolated by collagenase using Langendoff perfusion apparatus were spin labeled with 3maleidoproxyl. The hs/hw ratio and rotational correlation time were measured according to the spin labelingESR spectra. Results: The hs/hw ratio of 2 and 6 h postburn groups increased significantly postburn compared with that of shamburn group, and so did the rotational correlation time(τc) in 1 to 12 h postburn groups. Conclusion: There are structural and functional changes in cardiac myocyte membrane after burn injury. They are characterized by increase of hs/hw ratio and rotational correlation time. They could affect the normal performance of cardiac function.