γ射线照射对小鼠皮肤缺损创面愈合的影响及其机制探讨

摘要

Objective To observe the effect of γ-ray on wound healing of skin defect in mice and to explore its mech-anism.Methods A total of 60 healthy male C57BL/6 mice were randomly divided into the control group (n=30) and observation group (n=30).Those C57BL/6 mice in the observation group were irradiated 5 minutes with a single dose of 60Co-γ-ray (6 Gy).After the mice were anesthetized and sterilized , 1 cm ×1 cm wound to fascia on the back was made , the wound was covered by the TegadermTM paster , and we cleaned the wound every other day .Those mice in the control group were not irradiated , and the other treatments were the same as that in the observation group .The wound residual area was measured using Image analysis system (Image Proplusv 1.5) in the two groups on day 3 (T0), 7 (T1) and 14 (T2) after damage, and the number of new capillaries and fibroblasts in wound were observed at the same time .The mRNA ex-pression levels of vascular endothelial growth factor (VEGF), basic fibroblast growth factor-2 (FGF-2), platelet-derived growth factor ( PDGF) and transforming growth factor-β( TGF-β) in the dermal defects were detected by Real-time PCR. Results With the extension of time , the residual wound areas gradually reduced in the two groups , and the newborn capil-laries and fibroblasts in wound first increased and then decreased .The residual wound areas were larger in the observation group than those of the control group at different time points .The number of new capillaries at T 0 , and the number of fibro-blasts at T0 and T1 in observation group were lower than those of the control group at the same time points (all P<0.05). The mRNA expression levels of VEGF , PDGF and TGF-βat T0 and T1 and the FGF-2 mRNA expression level at each time point in the observation group were lower than those of the control group at the same time points (all P<0.05).Conclu-sion The γ-ray can delay the wound healing of skin defect in mice , and it may be related with the decreased expression of angiogenesis factor and fibroblast factor and inhibition of the angiogenesis and granulation tissue formation .%目的：观察γ射线照射对小鼠皮肤缺损创面愈合的影响，并探讨其可能的机制。方法将60只健康雄性C57BL／6小鼠随机分为观察组和对照组，各30只。观察组采用60 Co-γ射线（6 Gy）照射小鼠全身5 min，照射后腹腔麻醉消毒，于小鼠背部造成深及筋膜的1 cm ×1 cm大小皮肤缺损创面，用TegadermTM贴膜覆盖创面后隔日换药。对照组不予射线照射，其余处理同观察组。两组于造模后第3天（ T0）、7天（ T1）、14天（ T2），采用Image Prop-lusv1．5图像分析系统测量残余创面面积，记录创面组织新生毛细血管及成纤维细胞数量，采用Real-time PCR法检测创面组织血管内皮生长因子（ VEGF ）、碱性成纤维因子2（ FGF-2）、血小板衍生因子（ PDGF ）、转化生长因子β（ TGF-β） mRNA相对表达量。结果随着时间的延长，两组残余创面面积逐渐减小，创面新生毛细血管及成纤维细胞数量均先升高后降低。观察组各时点残余创面面积均超过对照组，T0时点新生毛细血管数量和T0、T1时点成纤维细胞数量均低于对照组，P均＜0．05。观察组T0、T1时点VEGF、PDGF、TGF-β和各时点FGF-2 mRNA相对表达量均低于对照组，P均＜0．05。结论γ射线照射可以导致小鼠皮肤缺损创面愈合延迟，可能与其降低血管生成因子和成纤维因子表达，从而抑制新生血管和肉芽组织形成有关。