缺血-再灌注对甲床损伤机制的实验研究

目的探讨使用止血带后缺血-再灌注对甲床组织的损伤及其相应的作用机制。方法大耳白兔于右后肢根部上止血带,于缺血30、60、90、120 min再灌注1 h后剥离甲床组织。分光分析法检测标本中超氧化物歧化酶（SOD）活性。荧光定量PCR检测标本中TNF-α基因的mRNA表达水平。TUNEL法检测细胞凋亡。结果甲床组织缺血30 min后再灌注SOD活力、TNF-αmRNA表达和细胞凋亡率无显著改变（P〉0.05）。与缺血30 min比较,缺血60 min后再灌注甲床组织SOD活力显著降低（P〈0.01）,TNF-αmRNA的表达显著增加（P〈0.01）,细胞凋亡率逐渐升高（P〈0.01）,但缺血90 min与120 min细胞的凋亡率比较差异无统计学意义（P〉0.05）。结论缺血60 min后再灌注可以诱发甲床细胞凋亡的发生,可能是术后指甲畸形的主要致病机制,SOD的减少和TNF-α表达的升高是导致细胞凋亡的主要原因。

Study of ischemia-reperfusion injury on nail bed and its mechanisms

Objective To investigate the effects of ischemia-reperfusion injury on nail bed by tourniquet and its mechanisms.Methods The model of nail bed ischemia-reperfusion injury was established by using rabbit which were used tourniquet on the right back leg.The activity of SOD was detected by spectrophotometer.Real-time PCR was used to detect the mRNA expression of TNF-α.The apoptosis was detected by TUNEL analysis.Results The the SOD activity,TNF-α mPNA expression,and apoptosis were not change by ischemia 30 min and reperfusion in nail bed tissue.Compared with 30 min,the SOD activity was decreased by ischemia 60 min and reperfusion in nail bed tissue(P < 0.01),after ischemia 60 min and reperfusion treatment,the mRNA expression of TNF-α was down regulated by Real-time PCR analysis(P < 0.01),TUNEL analysis showed that the apoptotic cell death was induced(P < 0.01).But the apoptotic cell death had no difference between ischemia 90 min and reperfusion and ischemia 120 min and reperfusion(P > 0.05).Conclusion The ischemia 60 min and reperfusion injury is a important reason to induce apoptosis in nail bed tissue,may be the main mechanism of nail duplication after operation.The low SOD activity and high TNF-α mRNA expression are the main reasons to induce apoptosis.