[Effect of continuous elastic outside distraction on change of collagen content in female minipig's nipples and their supporting tissues].
OBJECTIVE
To observe the effect of continuous elastic outside distraction on the change of collagen content in female minipig's nipples and their supporting tissues, and to investigate the mechanism of continuous elastic outside distraction correcting inverted nipples.


METHODS
Three 3-month-old female minipigs (weighing 18.5-22.0 kg), which had 12 nipples, were employed. Four nipples of each minipig were not treated as control group (n = 12), and the other nipples were continuously distracted with inverted nipple correction instruments as experimental group (n = 24). The nipple specimens were harvested at 2, 4, 8, and 12 weeks after distraction and HE staining was performed to observe the change of their tissue structure. And saturated picric acid sirius red staining was used to observe the distribution and content of collagen types I and III, image analysis software for quantitative analysis.


RESULTS
The control group had normal structure of epidermis at all time points. In experimental group, the epidermis thickened; basal cells, fibroblasts, and capillary significantly proliferated along with the times; and the content and the density of collagen types I and III increased gradually. There were significant differences in collagen type I at 4, 8, and 12 weeks, and in collagen type III at 2, 4, 8, and 12 weeks between 2 groups (P < 0.01). There were significant differences in the ratio of collagen type I to III at 2 and 4 weeks between 2 groups (P < 0.05).


CONCLUSIONS
Continuous elastic outside distraction can increase the quantity of collagen types I and III in the tissue, the thickness of the dermis, and the height of the nipple, which may be one of key mechanisms of correction the inverted nipple by continuous elastic outside distraction.
Department of Plastic and Burns Surgery, Affiliated Hospital of Luzhou Medical College, Luzhou Sichuan 646000, PR China. drgpwu@yahoo.com.cn
Guoping
G
Wu
Xiaochuan
X
He
Yanchuan
Y
An
Chunbing
C
Hu
Zhihui
Z
Yang
Li
L
Guo
Li
L
Teng
D000818:Animals; D001941:Breast Diseases / Q000378:metabolism / Q000601:surgery; D003094:Collagen / Q000378:metabolism; D024042:Collagen Type I / Q000378:metabolism*; D005260:Female; D009558:Nipples / Q000002:abnormalities / Q000378:metabolism* / Q000601:surgery*; D013552:Swine; D013556:Swine, Miniature; D014143:Traction
D024042:Collagen Type I; D003094:Collagen