【摘要】 目的:建立并评价大鼠急性放射性皮炎/溃疡模型。方法:将48只雌性Wistar大鼠随机分成8组,采用直线加速器发射高能X线建立模型,分别以0、5、15、30、35、38、43、50 Gy的剂量单次局部照射各组大鼠双后肢,筛选确定大鼠急性放射性皮炎和急性放射性溃疡的最佳照射剂量,再将46只同样大鼠随机分成模型1组(38 Gy,20只)、模型2组(43 Gy,20只)和空白对照组(6只),分别于照射后第18、60天观察两组模型照射区域皮肤变化情况、存活情况等,通过光镜和电镜观察其皮肤病理学变化,并与对照组比较。结果:当照射剂量为38 Gy时,大鼠皮肤见显著充血及水肿性红斑;光镜下观察表皮结构完整,真皮间质水肿,伴少量淋巴细胞浸润;电镜下观察细胞核异染色质增多,有核固缩现象。当照射剂量为43 Gy时,其皮肤见红斑、糜烂及较多溃疡;光镜下观察其表皮部分坏死,真皮浅层高度水肿,毛细血管管壁变性坏死;电镜下细胞核固缩明显,细胞器明显变性,血管壁变性坏死。结论:直线加速器单次局部照射38 Gy和43 Gy,可分别成功诱导大鼠双后肢发生急性放射性皮炎和急性放射性溃疡。该两种模型能分别反映大鼠急性放射性皮炎和溃疡模型的临床特征和病理特征,可用于实验研究。更多还原

【Abstract】 Objective: To establish the rat models of acute radioactive dermatitis/ulceration.Methods: Forty-eight rats were randomly assigned to eight groups,locally treated on two back legs by different dosage of X-ray radiation respectively at 0-,5-,15-,30-,35-,38-,43-and 50 Gy.After phenotypic analysis of optimal dosages for each model,46 female Wistar Rats were randomly distributed into 38-Gy group( n = 20),43-Gy group( n = 20) and control group( n = 6). After 18days,60 days,the change of the skin and hair in irradiation area and survival situation of the models were visual assessed,and the pathological changes of the skin were detected with optical microscopy and scanning electron microscopy. Results: The rats irradiated by a 38-Gy X-ray pres-ent marked hyperemia and edematous erythema,and hair loss in the exposure zone. Optical microscopy revealed the integral epidermis structure,interstitial edema,genuine layer were infiltrated with a small amount of lymphocytes. SEM showed nucleus heterochromatin and nuclear pyknosisincreased. After 43-Gy irradation,the skin erythema,erosion and more ulcers were observed. Microscopically,the partial epidermal necrosis,significant edema at the upper dermis,degeneration and necrosis of capillary blood vessels,surrounded by a large number of neutrophils,eosinophils and nuclear dust distribution can be obsvered. Ultra-structure analysis were presented in those fingings such as the nucleus pyknosis,cell organelle degeneration,hemal wall degeneration necrosis. Conclusion: Rat models of acute radioactive dermatitis and acute radioactive ulceration were successfully established by 38-Gy and 43-Gy high-dose X-ray radiation respectively,the appearance of the models in the clinical and histopathological were resembe with the features of acute radioactive dermatitis and ulceration.更多还原