The effect of continuous elastic outside distraction on the expressions of vascular endothelial cell growth factor and microvessel density in female porcine nipple.

BACKGROUND

We have proposed a method to correct the inverted nipple with good clinical results. The aim of the study presented here is to show the effect of continuous elastic distraction on the expression of vascular endothelial growth factor and microvessel density in the female porcine nipple. This article also explores the probable mechanism correction of inverted nipples.

METHODS

Four female 3-month-old pigs each with 12 nipples were used. Four nipples of each minipig were used as control with the other eight nipples continuously distracted with prefabricated instruments. The nipples were excised at weeks 2, 4, 8, and 12 after distraction. Immunohistochemical staining was performed to observe the expression of vascular endothelial cell growth factor (VEGF) and CD34 in those tissues. The integral optical density of VEGF-positive cells and microvessel density (MVD) were also counted.

RESULTS

The volumes of the nipples all increased after traction compared with those of the control group. The diameters and heights of the nipples showed significant changes (P<0.01). In immunohistochemical staining, the expressions of VEGF and CD34 of all distracted groups were positive. The staining intensity of traction groups was moderate and that of the control groups was weakly positive. The integral optical density of VEGF-positive cells and MVD compared with the control group were significantly different (P<0.01), and there was a significant positive correlation in MVD and VEGF.

CONCLUSION

Continuous elastic distraction can promote the expression of some growth factors in nipples.