血管内皮生长因子对小型猪腮腺放射性损伤影响的实验研究

目的：应用血管内皮生长因子（VEGF）对放疗后腮腺微血管内皮损伤进行保护,改善微血管内皮细胞功能,评价其对腮腺放疗后早期腺体及血管变化的影响。方法：将9只实验用小型猪分为三组（n=3）。空白对照组,单纯放疗组逆行注射4ml生理盐水至腮腺导管,VEGF给药放疗组通过腮腺导管逆行注射1μg（4ml）重组人VEGF165蛋白至腮腺。11天后三组动物双侧腮腺进行放疗,空白对照组0Gy/每侧,VEGF＋放疗组及单纯放疗组20Gy/每侧。放疗后4小时取腮腺标本行HE及免疫组化染色,观察腮腺早期组织学与微血管密度变化。结果：三组小型猪腮腺CD31阳性染色颗粒数有显著差异（F=47.727,P〈0.01）;VEGF给药放疗组较单纯放疗组CD31染色颗粒密度明显增高。空白对照组与两放疗组比较AQP1阳性染色颗粒数有统计学意义（P〈0.05）;VEGF＋放疗组与单纯放疗组比较无统计学意义（P〉0.05）。结论：放疗后4小时腮腺组织CD31、AQP1表达明显下降。放疗前导管逆行注射VEGF可使放疗后腮腺组织内微血管密度升高。

Effect of vascular endothelial growth factor (VEGF) on Salivary Gland Radioactive Damage of Miniature Pig

Objective：To observe the early cytologic changes of vascular endothelial cell in irradiated miniature pig parotid glands,we applied vascular endothelial growth factor（VEGF） to reduce the early radioactive damage of the vascular endothelial cells and improve the function of them. We also estimated the effect of VEGF on irradiated microvessels of salivary glands. Methods：Nine male miniature pigs were divided into two irradiation（IR） groups and one control group（n=3 each） . The IR groups were subjected to 20 Gy X-radiation to two parotid glands,the control group was subjected to 0 Gy X-radiation to two parotids. The medication group was delivered 1μg（4ml） VEGF by polyethylene tubing cannulated to the anterior part of the parotid duct at 11 days before irradiation. The other two groups were deliverd 4ml normal saline. Then 4 hours after irradiation,we executed the miniature pigs and picked up their parotid to evaluate microvessels density（MVD） by hematoxylin-eosin（HE） staining and immunohistochemical study. Results：There were significant difference between control group,IR medication group and IR control group in the quantity of CD31 stained cells of vascular endothelial cell in minipigs parotid glands（F=47.727,P0.01） . The quantity of CD31 stained cells significantly increased in IR medication group than in IR control group.there was significant difference between blank control group and two IR group in the number of AQP1 stained cells of vascular endothelial cell in irradiated minipig paratid glands（F=18.707,P=0.000）;but no difference in IR medication group and IR control group（P0.05） . Conclusion：Inject VEGF to parotid duct could improve the microvessels density of the irradiated parotids. Irradiation could reduce CD31 and AQP1 stained cells which reflect MVD in minipigs parotid glands.