外源性VEGF影响大鼠背部放疗皮瓣成活性的实验研究

目的研究局部注射不同剂量血管内皮细胞生长因子（VEGF）对放疗中大鼠背部皮瓣成活情况的影响,探讨放疗过程中外源性VEGF干预皮瓣血液循环重建的作用机制。方法60只雌性Wister大鼠,体重200±20克,随机分为6组,A-F组。大鼠背部做3 cm×4 cm带蒂全厚皮瓣,术后第2、4、6天给予钴60照射,总剂量12 Gy。A、B、C、组术后第3天于皮瓣下,注入不同剂量VEGF,A组：80纳克/只、B组：120纳克/只、C组：160纳克/只、D组：生理盐水有照射、E组：生理盐水无照射、F组：120纳克/只无照射。实验结果检测采用肉眼观察、组织病理学、血循环荧光染色结合photoshop图像色彩分析,评价皮瓣内血液循环及皮瓣成活情况。结果C组皮瓣血管网密度、血管数量,较E组升高（P〈0.05）,各治疗组间皮瓣血液循环及荧光染色与VEGF有剂量依赖性,染色最强的是F组,与D组有显著性差异（P〈0.05）。结论足量的VEGF局部皮下注射能有效促进皮瓣的血管形成,解决由于放疗引起的自体皮瓣成活降低的问题。

An experimental study of different quantity extrinsic Vascular Endothelial Growth Factor (VEGF) effect on the viability of radiotherapy on sink flap in rat

Objective The purpose of the study was to analyze the relationship between the vascular endothelial growth factor（VEGF） and the survival of flap on the back of rat via radiotherapy by injecting VEGF into rat flap directly.Methods Establish the animal model with Wister rat： A 3 cm×4 cm full thick dorsal flap with the pedicle remained was attached to the posterior end.60Co radiotherapy was administered to the flap postoperatively on the 2nd,4th,and 6th day respectively,with a total quantity of 12 Gy.Different dosage of VEGF was administered radiate to the same place on the 3 rd day after be operated.This experiment adopted eye-naked observation,pathological examination and circulate fluorescence staining skill combined with photoshop color analysis.Results Compared with the control group,the density of blood net and the number of blood vessel in the high-dosage group was significantly increased（P〈0.05）.There was a dosage-dependent relationship of flap activity and fluorescence staining with the VEGF between the groups.There was a marked change between the single radiated group and the simply normal saline group which stains the darkest（P〈0.05）.Conclusion Adequate injection of VEGF subcutaneously could effectively improve the survival flap caused by radiotherapy.