大鼠放创复合伤时皮肤创伤愈合的形态学观察

Morphological study on healing of cutaneous wound combined with radiation-trauma injury in rats

目的 探讨全身辐射对创伤后皮肤愈合的组织学与超微结构变化特点。方法 用6 0 Coγ射线照射 2、4、6Gy ,并在大鼠背部致 2 .5 %体表面积全层皮肤创面 2个。于伤后不同时间 ,用HE染色、透射电镜观察其创面变化及形态学改变。结果 放创复合伤后 ,创伤愈合速度随照射剂量增加而明显减缓。单创组伤后 3d创面底部即见成纤维细胞增生 ,伤后 10～ 15d ,胶原瘢痕形成 ,可见新生血管网、神经末梢 ,表皮细胞生长逐渐覆盖伤口 ,2 0d时创面已愈合。但 6Gy组损伤严重 ,伤后 3d见大量渗出物、血凝块、坏死组织 ,15d表皮细胞蔓延生长缓慢 ,仍见胞核异型、扭曲、皱褶。 2Gy组影响较轻 ,伤后 7d已有肉芽组织生长 ,15d见纤维瘢痕形成。结论 放创复合伤时皮肤愈合过程较为复杂 ,肉芽组织及表皮细胞生长的受抑程度随照射剂量增加而加重。

Objective To study the pathological changes and the morphological characters of the healing process of cutaneous wound combined with total body irradiation in rats. Methods Rats were irradiated at the single doses of 2, 4 and 6 Gy from a 60 Co γ ray source. Within 1 h after irradiation, two whole thickness circular wounds were produced on the back of the animals, corresponding to 2.5% of total body surface area. The pathological changes were observed by HE staining and transmission electron microscopy (TEM). Results After total body irradiation combined with cutaneous wound, the rate of healing was significantly retarded as the irradiation dose increased. Histological results showed that in rats with single wound, on the 3rd day after injury proliferation of fibroblasts in wound bottom was observed; on days 10～15 after injury, collagenic scar formed, vascular net and nerve ending regenerated, and epidermic cells continually grew to cover wound gradually; on the 20th d after injury wound was basically healed. However, in rats combined with 6 Gy radiation, on the 3rd d after injury, a large amount of extract, necrosis tissues, bacterial colonies and inflammatory infiltrations were seen in the wound, but fibroblast growth was not seen in wound bottom; on the 15th d after injury epidermic cells grew slowly, abnormal cell nuclei with turn and ruga and chromatic clumping were also seen; in rats combined with 2 Gy radiation, the effect of radiation on the healing of wound was slight, but there was growth of granulation tissue (7th d) in the wound. Conclusion In soft tissue trauma combined with radiation injury, the changes of morphological character are far more complicated. The growth inhibition of granulation tissues and epidermic cells is definitely related to the dose of radiation inflicted.