放射延迟伤口愈合机制的初步研究

目的：初步探索放射延迟伤口愈合的机制。方法：用光镜、电镜及原位末端标记法并结合图象分析技术,观察大鼠创伤组和放射复合创伤组伤口病理形态学、伤口面积和伤口区细胞数量、细胞凋亡等方面的变化。结果：（1）照射后伤口愈合：早期炎症反应明显受抑,创面渗出物减少,出血、坏死明显;中期肉芽组织生长成熟减慢,伤口收缩受到抑制;后期上皮覆盖滞后,与单伤且相比愈合时间明显延长。伤口面积测定显示：在伤口愈合过程中伤照组面积始终大于单伤组。（2）肉芽组织中细胞数量测定：照射后伤口区细胞数量的增多明显滞后于单伤组,部分成纤维细胞出现变性、坏死。（3）细胞凋亡在伤口愈合中的发生规律分析：与单伤组相比,伤照组细胞凋亡出现较早、频率较高、消失推迟。结论：大剂量辐射确实可延迟伤口愈合;辐射后细胞数量、形态及功能异常,尤其是细胞凋亡发生过度,可能是导致辐射延迟伤口愈合的延迟伤口愈合的重要机制。

Preliminary analysis of delayed wound healing induced by radiation

Objective:To analyze the mechanism of delayed wound healing induced by radiation.Methods:Using microscope,transmission electron microscope(TEM),in situ terminal labeling (TUNEL) with image analysis technique,we observed the changes in pathomorphology,wound area,cell quantity and apoptosis in the wound of trauma and traumaradiation combined wound of rats.Results:(1) In early stage of wound healing after radiation,inflammation was inhibited,exudation of wound surface decreased,hemorrhage and necrosis was evident.In middle stage,the formation of granulation tissue was slow and wound contraction was suppressed.In late stage,epithelialization was delayed,wound healing time was obviously slower than that of pure trauma wound.Wound area in radiation combined wound group was larger than that of trauma wound alone.(2) Cell quantity in granulation tissue of radiation combined wounds was significantly less than that of pure trauma wounds,degeneration and necrosis were found in some fibroblasts.(3)Apoptosis occurred earlier and disappeared later,and frequency of apoptosis was higher in radiation combined wounds when compared with those in trauma wounds.Conclusions:Large dose radiation could delay wound healing.The abnormalities in quantity,morphology and function of cells,especially the excessive apoptosis,might be the important mechanism of delayed wound healing induced by radiation.