持续弹性外牵引对小型猪乳头及其支撑组织微血管生成的影响

Effect of cnntinunus elastic outside distraction on microvessel density in female minipig＇s nipples and theirsupporting tissues

目的探讨持续弹性外牵引对小型猪乳头及其支撑组织做血管生成的影响．以闸叫其矫正乳头内陷的作用机制。方法选用3个月龄雌性小型猪3只．每只均有12个乳头，共计36个乳头。每只猪留取1个乳头作为空白对照组．其余8个安放乳头内陷矫治器进行持续弹性外牵引为实验组，分别于牵引后2、4、8、12周切取每只小型猪的1个空白组乳头和2个实验组乳．将切除的乳头标小分别行免疫组织化学染色观察血管内皮细胞生长因子（VEGF）、CI）34在组织中的表达．统计期阳性细胞的百分比及微血管密度（MVD）的变化。结果实验组CD34、VEGF在2周表达增强．4周达最高峰，8、12周逐渐减弱．对照组表达较弱。VEGF阳性表达的秋分吸光度值及MVD与对照组比较差异均有统计学意义（P〈0．01），二者行之间呈显著正相关。结论持续弹性外牵引可促进乳头及其支撑组织VEGF及CD3，1表达和微血管，生成，增加局部氧供给，从而使局部组织增生．是矫正乳头内陷的理论基础之一。

Objective To explore the effect of elastic oulside distraction on microvessel density and to illustrate the mechanism correcting inverted nipples. Methods Three female 3- month old minipigs, with 12 nipples each, were employed. 4 nipples of each minipig were remained without dis- traction were control group, and tile other 8 nipples were continuously distracted with inverted nipple correction instruments. Corresponding nipples were excised at 2, ,4, 8 and 12 weeks after traction. The excised nipple specimens were employed with immunohislochemical staining to detect the expres- sion of vascular endothelial culls growth factor （VEGF） and CD34 in those tissues, and the percentage of positive cells and microvessel density （MVD） changes were counted. Results The expression of CD34 and VEGF in the experimenlal groups increased at 2 weeks after tracted, and reached at the peak at 4 weeks, then gradually decreased during8 to 12 weeks after tracted. While those were weakly positive in control group. Compared with the control group, the integral optical densityo{ VEGF-posi rive cells and MVI） were significantly different （P〈0.01）, and there was a significantly positiw： cor- relation between MVD and VEGF, Conclusions Continuous elastic outside distraction can promote the expression of VEGF and CD34 in female minipig nipple and enhance angiogenesis, which increases oxygen supply locally, and therefore those local tissue proliferation may be one of key mechanisms of correcling the inverted nipple by continuous elastic outside distraction.