超长皮瓣局部应用血管内皮生长因子促其成活与氧自由基相关性的实验研究

目的超长随意皮瓣局部应用VEGF,探讨外源性VEGF对超长皮瓣成活与氧自由基的相关性。方法实验于2004年11月—2005年11月在华北煤炭医学院中心实验室完成。采用SD大鼠背部3cm×10cm单蒂缺血皮瓣模型,皮下局部注射血管内皮细胞生长因子后第十二、二十四小时检测皮瓣组织的MDA和SOD含量,通过计算机图像分析技术对皮瓣成活率进行测定、微血管密度的测定、组织学检查等手段来观察内皮细胞生长因子对缺血皮瓣成活的影响并探讨其机制。结果局部应用血管内皮细胞生长因子后,第二十四小时生理盐水组MDA含量中1/3段为(5.42±1.35)nmol/mgprot,内皮细胞生长因子组中1/3段为(2.79±0.22)nmol/mgprot;SOD活力测定在生理盐水组中1/3段为(58.27±12.81)U/mgprot、远1/3段为(109.71±40.13)U/mgprot,内皮细胞生长因子组中1/3段为(116.61±19.83)U/mgprot、远1/3段为(177.07±3.41)U/mgprot;表明内皮细胞生长因子能提高SOD活力,增强对自由基MDA的清除。组织学检查发现内皮细胞生长因子能促进皮瓣组织毛细血管增生。生理盐水组微血管密度中1/3段为(25.57±0.88)个/cm2、远1/3段为(25.2±0.40)个/cm2,内皮细胞生长因子组中1/3段为(31.76±0.77)个/cm2、远1/3段为(37.26±2.97)个/cm2;说明了内皮细胞生长因子能增加中远段皮瓣组织的微血管数量。结论内皮细胞生长因子能促进缺血皮瓣成活,其机制可能与内皮细胞生长因子直接促进毛细血管新生、提高SOD表达增加对氧自由基MDA的清除间接促血管新生相关。

EVALUATION OF THE MECHANISM OF VASCULAR ENDOTHELIAL GROWTH FACTOR IMPROVEMENT OF ISCHMIC FLAP SURVIVAL WITH RELATION TO FREE OXIDE RADICAL IN RATS

Objective To observe the effect of VEGF on survival of ischemia skin flap,An experimental study was designed on improvement of vascular endothelial growth factor in survival of ischemic flap with relation to free oxide radicals in rats.Methods The experiment was conducted in the central laboratory of Hebei United University from Nov.2004 to Nov.2005.A caudally based,rectangular,dorsal flap,measuring 3 x 10cm,was raised on the back of SD rat.After subcutaneous injection of VEGF,detection of histological examination of MDA and SOD postoperative 12h and 24h,measurement of microvessel density(MVD),histological examination,those were performed by computerized image analysis technology to observe the influence of VEGF on ischemia flap survival and probe into its mechanism.Results As shown by histological examination,the MDA level in the distal part of the flaps in VEGF treated group was 2.79±0.22 nmol/mgprot at 24h postoperatively,that in the control was 5.42±1.35 nmol/mgprot.The SOD level in VEGF treated group was 116.61±19.83 nmol/mgprot for middle part and 177.07±3.41 nmol/mgprot for distal part.At the same time,the SOD level in salin treated group was 58.27±12.81 nmol/mgprot for middle part and 109.71±40.13 nmol/mgprot for distal part.The results suggested that VEGF upregulated the production of SOD to clearance of free oxide radicals.Histopathology showed that abundant capilliary were noticed by application of VEGF.The MVD in salin group was 25.57±0.88 per cm2 for middle 1/3 and 25.2±0.40 per cm2 for distal 1/3 segement;The MVD in VEGF group was 31.76±0.77 per cm2 for middle 1/3 segement and 37.26±2.97 per cm2 for distal 1/3 segement.The results indicated that VEGF increased the MVD in the middle and distal segements of flaps.Conclusion VEGF can improve ischemia survival.The mechanism may be that VEGF accelerate angiogenesis directly,upregulate SOD expression to clearance of free oxide radicals.