The Exploration Of The Chondrocytes Development And Lymphatic Vessel Growth In The Process Of Endochondral Ossification Of Mice

Research objectives:by observeing Ⅱ type collagen, this paper study the development situation of the chondrocytes in the process of entochondrostosis. And through the detecting the expression of lymphatic endothelial cell markers LYVE 1 and lymphatic vessel growth factor of VEGF-C, it elaborates the effects of VEGF-C on lymphatic vessel growth during cartilage ossification, and thoroughly discuses about the relation between the lymphatic vessels and endochondral ossification, and provide theoretical reference for the endochondral ossification process as well as the growth cartilage damage repairing, and it also has positive significance for promoting the health of adolescents bone development.Research method:take bilateral femurs of 1,3,5,7,9,11,13,15,17,19 days age mices, using HE staining, to observe changes of the femoral cartilage chondrocytes and vascular invasion in the process of development. Immunohistochemistry method are used to observe the expression of type Ⅱ collagen, LYVE 1 in per femur. By using (rt-pcr) method, detect the expression of type II collagen, LYVE-1, VEGF-C.Research results:1.Femoral growth process is characterized by entochondrostosis. the primary ossification center has formed before birth, the secondary ossification center has not yet formed.2.Vascular invades the epiphyseal on the 7th day since the birth, and it begins to form secondary ossification center.With age increasing, the secondary ossification center expands unceasingly. On the 13th day, there’s a mass blood vessels invading the epiphyseal growth zone, meanwhile the cartilage matrix is extensive calcified. On the 19th days, the vascular invasion decreased, but the epiphyseal has not completely calcified.3.As the cartilage cell proliferating, differentiating, type Ⅱ collagen mainly express in the zone of proliferation and hypertrophy of chondrocytes. LYVE-1 express in the zone of hypertrophy and osteogenesis zone. As the age increases,The trend of type Ⅱ collagen expression was rising, and it began to decline at since the 15th day. the expression of LYVE-1mRNA is on the rise at the 5th days and the 13th days. VEGF-CmRNA expression and LYVE-1 mrna expression were positively correlated, the overall trend is basically consistent.Research conclusions:1.The osteogenesis of femur performs the form of entochondrostosis, femoral epiphyseal plate growth zone is different to the secondary ossification center epiphyseal growth zone no cartilage cell hypertrophy.2.Lymphatic vessels were found to exist in the process of entochondrostosis, mainly in zone of hypertrophy and osteogenesis.3.Vascular growth factor VEGF-C changing trend was positively related with LYVE-1, which is consistent with lymphatic vessel growth change.