The roles of estrogen in the process of angiogenesis during wound healing and its mechanisms

Objective To investigate the effect of estrogen on the revascularization of full-thickness skin wounds healing in rats. Methods Forty 2-month-old female Wistar rats were divided into three groups: control group (group A, pure injury,n = 15), ovariectomized group (group B,n = 15) and sham operation group (group C,n = 10 ). After 8 weeks, full-thickness wounds model, 18 mm in diameter, were made on the back of the each animal. The volume of wound was measured at each time point. The specimens of wound edge were obtained at the 1st, 3rd, 7th, 14th and 21st day after injury. The process of wound healing and the number of microvessels in the granulation tissue were evaluated by Haematine-Eosin (HE) staining. The immunohistochemical staining was used to detect the expression of estrogen receptor β (ER-β) in microvascular endothelial cells and their surrounding cells. Results To compare the volume of wound at each time point, the granulation tissue formation in group A and group C was significantly higher than that in group B, but there was no significant difference between group A and group C. The number of capillary blood vessels in group B was significantly reduced as compared with that in group A. The expression of ER-β was positive on the cells surface in all groups. ER-β expression in group B was weaker than in group A ( 159. 91 ± 12. 65 v. s 189. 36 ±27. 32,P ＜0. 05). Conclusion The delay of wound healing in ovariectomized rats has a great relationship with angiogenesis. Estrogen and its receptor might play important roles in the process. Key words: Wound healing; Capillary blood vessel; Angiogenesis; Estrogen; Receptor