Objective To review the regulating effects of estrogen on endothel ial cell functions, the involved endothel ial progenitor cells (EPCs), and the related VEGF, and explore the mechanism of estrogen participating in new vesselformation on wound basement and wound heal ing. Methods Recent l iterature about biological effects of estrogen oncapillary vessel formation was reviewed. Results The formation of new vessel in the wound’s granulation tissue contained vasculogenesis and vascularization, and the new vessels could transport the oxygen and nutrient for the metabol ism of the local heal ing tissue. The estrogen effected vascular endothel ial cells through its receptors. Peripheral vascular EPCs differentiated into endothel ial cells and participated into the formation of new vessels. Estradiol exerted influences on the dynamics of vascular EPCs and the neovascularization. VEGF was a key mediator in the processes of estradiol regulating angiogenesis. Conclusion Understanding the molecular mechanisms that regulate vessel formation in wound heal ing, especially how estrogen modulates its receptor and angiogenic factor, may provide new approaches for managing wound heal ing.
To investigate the influence of injury of nutrient artery on the blood supply of inner 2/3 of cortical and intramedullary tissue, the experiment was carried out on twenty-four rabbits. Four rabbits were killed and perfused with Chinese ink in femoral artery to survey the blood supply of intramedullary vessels. Others were received fracture on tibia and sacrificed respectively on the third, eighth, eighteenth, twenty-eighth, and forty-second days after fracture. Chinese ink was also perfused through femoral artery on those rabbits. The relative density of capillary vessels were determined. The results were as follows: when the nutrient artery was injured after fracture, blood supply to the intramedullary tissue and the inner 2/3 of cortical bone was interrupted. The intramedullary vessels were increared and dilated. During the whole course of healing of fraeture, the density of intramedullary capillary vessels were higher than normal. It was concluded that the anastomosis between the epiphysis and metaphysis was important in the reconstruction of collateral circulation in healing of fracture.