沙榆油对β射线致放射性皮肤损伤大鼠皮肤组织病理学及P53基因表达的影响

Effect of Elm Oil on Skin Histopathology and P53 Gene Expression in Rats with Radioactive Skin Injury Induced by β-rays

目的评价沙榆油防治急性放射性皮肤损伤的疗效,并探讨其病理学机制和对凋亡相关基因P53表达的影响。方法 40只雌性SD大鼠用硫化钡进行臀部皮肤脱毛,随机选取10只为空白组,其余30只麻醉后以直线加速器电子线6Me V单次照射,吸收剂量率为225c Gy/min,累计剂量45Gy,照射后随机分为模型组、治疗组、对照组各10只,分别给相应处理,观察照射野皮肤变化,光镜观察皮肤组织学改变,免疫组化检测P53基因表达情况。结果受照大鼠均发生皮肤损伤,治疗组最轻,模型组最重,对照组居中;光镜观察发现照射第14d,受照射大鼠皮肤均出现明显的病理改变,毛囊上皮破坏,大量炎性细胞浸润;照射第30d,治疗组与对照组均可见部分创面修复,以治疗组为著,见纤维母细胞、胶原纤维增生,而模型组创面皮损显著,表皮层及真皮浅层组织坏死,真皮内水肿,毛细血管扩张、出血,广泛中性粒细胞、淋巴细胞浸润;受照大鼠皮肤P53基因在第14d均呈高表达,至第30d治疗组明显降低,与模型组及对照组相比差异具有显著性(P<0.05)。结论沙榆油对大鼠急性放射性皮肤损伤有明显的防治作用,其机制可能与其促进纤维母细胞、胶原纤维增生,降低P53基因的表达,从而抑制细胞凋亡有关。

Objective： To evaluate the effect of elm oil in the prevention and treatment of radioactive skin injury and probe into its pathological mechanism as well as its effect on P53 gene expression. Method： 40 female SD rats＇ buttock skin hair were removed by barium sulfide,10 were randomly selected as the blank group,the remaining 30 anesthetized rats were irradiated with 6 MeV linear accelerator electron beam at an absorbed dose rate of 225 c Gy/min with a cumulative dose of 45 Gy. Then the rats were randomly divided into model group,treatment group and control group with 10 rats in each,and given corresponding treatment. The changes of the skin were observed and the histopathological changes were observed by light microscope,the expression of P53 gene was detected by immunohistochemistry. Result： Skin damage occurred in the irradiated rats,the lightest was in the treatment group,the heaviest in the model group and the middle in the control group. On the 14 th day of irradiation,obvious pathological changes of the irradiated rat skin appeared,hair follicle epithelial damage and large amount of inflammatory cell infiltration were observed. On the 30 th day of irradiation,part of the wound repaired in both the treatment group and the control group,with the treatment group more obvious. Fibroblast and collagenous fiber proliferation were observed. The model group had significant skin lesions,epidermis and dermis superficial tissue necrosis,intradermal edema,telangiectasia,hemorrhage,extensive neutrophil and lymphocyte infiltration. The expression of P53 gene in the irradiated rat skin was highly expressed on the 14 th day,and significantly decreased on the 30 th day in the treatment group compared with the model group and the control group（ P 0. 05）.Conclusion： elm oil has a significant preventive and curative effect on acute radioactive skin injury in rats,and its mechanism may be related to promoting proliferation of fibroblasts and collagen fibers,reducing the expression of P53 gene and inhibiting cell apoptosis.