放射治疗兔耳增生性瘢痕的实验研究

Experimental study of radiation therapy for hypertrophic scar in rabbits' ears

目的:研究经过医用高能电子线照射兔耳增生性瘢痕实验模型后,观察伤口愈合的情况、瘢痕愈合后的病理改变及肌动蛋白(ACTIN)和血管生长因子(VEGF)表达变化情况。方法:选用日本大耳白兔18只,在每只兔耳腹侧面制作直径6mm的圆形全层皮肤缺损创面10个。将总计360个缺损创面模型随机分为6组,第1组为空白对照组(3只),其余5组为照射组(各3只)。将照射组每只兔耳随机用200cGy、400cGy、600cGy、800cGy、1000cGy的6Mev电子线照射兔耳缺损创面,照射野周围用铅板防护,观察兔耳缺损创面的愈合情况变化及创面愈合后瘢痕组织进展情况。并于致伤一个月后对实验模型取材,进行光镜、电镜及组织学观察。结果:兔耳腹侧面圆形创面缺损,能产生与人类增生性瘢痕类似的增生块。各照射组,缺损创面愈合延迟。总照射剂量相近的情况下,单次不同照射剂量对增生性瘢痕形成的影响有显著性差异。结论:日本大耳白兔可以形成类似人的增生性瘢痕病理改变,可以用作增生性瘢痕研究的实验动物模型。动物实验证明,医用6Mev高能电子线照射治疗是一种有效的治疗增生性瘫痕的方法,总照射剂量相近的情况下,分5次照射、单次剂量400cGy,为最佳照射剂量。

Objective The study went through after the irradiation of high energy electronic wires which was conducted on the experimental model of hypertrophic scar of rabbits＂ ears. Observed the healing process and showed the pathological change as well as the variation of actin （ACTIN） and vascular endothelial growth factor （VEGF） after the healing of the scar. Methods Selected 18 Japanese rabbits and made 10 models of circular fullthickness wound defects in the ventral side of per ear which each one was in the size of 6mm diameter. The total number of 360 wound defects was randomly divided into 6 groups. Group1 was the blank control group （3 samples）, and the other 5 groups were the radiation group （3 samples in each group）. Each wound defects on rabbits＇ears was randomly irradiated with 200cGy, 400cGy, 600cGy, 800cGy, 1000cGy 6Mev electronic wires and the radiation field around was protected by the stereotype. Observed the change during the healing process and the progress of the scar tissue after the wound defects had already healed. Got the experimental material 1 month after the treatment injury and continued on the observations of the light microscopy,electron microscopy and histology. Results The wound defects in the ventral side of the rabbits＇ears could produce the similar hypertrophic scar like human beings. Each radiation group showed that the healing of the wound defects was delayed. Under the similar amount of the radiation, different volume of radiation per time could result a significant difference on the formation of the hypertrophic scar. Conclusion Japanese rabbits＂ could produce the similar pathological change of hypertrophic scar like human beings, and they could be the experimental animal model for the observation on pathological scar. This experiment proofed that radiation with 6 Mev pathological electronic wires is an effective way to cure the hypertrophic scar. Under the similar amount of the radiation, radiating 5 times fractionally which measured 400 Gy each time was the best quantities.