压疮大鼠不同时间点缺血再灌注损伤的实验

Histopathological changes in rats with pressure sores induced by ischemia-reperfusion injury at different time points

目的探讨压疮中不同时间点缺血再灌注损伤中组织病理学变化,及其血管内皮生长因子(vascularendothelial growth factor,VEGF)含量的变化与意义。方法 2010年5月,我们将雄性SD大鼠15只按照随机数字表分为空白组和模型组。模型组中缺血再灌注压疮模型采取埋置铁片加外用磁铁施压方法,分别于1 d、3d、5d和10 d处死取组织,检测压疮不同时间点缺血再灌注损伤中组织形态学及VEGF变化。结果模型组随着缺血再灌注损伤时间的延长,损伤逐渐由表皮层延伸至真皮层、肌肉等。缺血再灌注损伤3 d后皮肤全层均呈慢性炎性改变,主要以淋巴细胞浸润、毛细血管扩张伴毛细血管瘀血为主。缺血再灌注损伤1 d后组织VEGF呈逐渐增高趋势,3 d时达到高峰后呈逐渐下降趋势,与空白组比较差异具有统计学意义(P<0.05)。结论缺血再灌注损伤在压疮形成中起着重要的作用,组织中VEGF水平呈现先升高再下降的趋势,提示压疮缺血再灌注损伤时组织存在血管生成、损伤的多阶段调控机制。

Objective To observe the histopathological changes in rats with pressure sores induced by ischemia-reperfusion injury and changes in vascular endothelial growth factor（VEGF） level at different time points,and investigate the related mechanisms.Methods Fifteen male Sprague-Dawley（SD） rats were randomly divided into the control group（n=3） and ischemia-reperfusion model group（n=12）.The ischemia-reperfusion model of rats was established according to magnetic iron compression method.The rats were sacrificed at days 1,3,5 and 10 after administration.The histopathological changes in rats with pressure sores induced by ischemia-reperfusion injury and changes in VEGF level at different time points were observed.Results In the model group,with prolonged ischemia-reperfusion injury,the damage gradually extended from the epidermis to dermis and muscle.At day 3,chronic inflammatory changes appeared in the skin,mainly presenting as lymphocytic infiltrates and capillary dilation with bleeding.The level of VEGF increased,peaked at day 3,and then declined.While in the control group,no histopathological changes were found in skin tissues.Conclusion Ischemia-reperfusion injury plays an important role in early stage of pressure sores.The level of VEGF first increases and then declines,showing effects on angiogenesis and tissue damage during ischemia-reperfusion injury.