Objective To investigate the spatial and temporal regulation effect of VEGF on human fetal retinal vascularization and angiogenesis. Methods The posterior segmental retinas from 54 human fetuses of the 9th week to the 40th week were studied by immunohistodhemistry standing for the expressions of VEGF and PCNA. Results 1. The distribution of VEGF espression was spiking and the peaks were during the 9th-13th and around the 26th week. 2. PCNA immunoreactivity was localized in spindle cells and vascular endothelial cells. The expression level was fluctuated during the developmental process. The peaks were during the 9th-13th and around the 21st week. In these periods, the spindle cells kept proliferating and differentiating, and remodelled subsequently to form the inner side retinal vessels. From the 26th or 34th week, the PCNA immununoreactivity is fully expressed in the vascular endothelial cells of the inner and outer margin of inner nuclear layer(INL) and kept to full terms. 3. Significant positive correlation were shown between the content of VEGF in the retina and that of PCNA in spindle cells and vascular endothelial cells(r=0.736,p＜0.01). Conclusion VEGF was positively involved in modulating human fetal retinal vascularization and angiogenesis. (Chin J Ocul Fundus Dis,1999,15:12-15)
PURPOSE:To observe tbe development of structure of the retinal blood vessels in human fetuses. METHODS:The retinas of 134 human fetuses from 12-weeks of fertilization to full term and of 4 adults were collected,and examined with immunohlstoebemical method. RESULTS:The examinations showed:(1)The spindle ceils only existed in the retinas of fetuseslt;27 weeks. Till full term,the vessels in ganglion cell layer(GCL)was still budding. (2)BM of all arterioles,venules and capillaries within the retinas of all fetuses and adults,was immunostained after exposure to antlsera against fibronectin.The laminin(LN)and type Ⅳ collagen(COL-Ⅳ)immunoreactive product appeared outside tbe endothelial cells of blood vessels in GCL at 25 weeks and 29 weeks,and tile b LN and COL-Ⅳ immunostaining around four layers of the retinal vessels in tile shape of sbeath appeared at 29 weeks and 32 weeks respectively. (3)As soon as the cords of the endothelial cells were canaized,the smooth muscle cells and perieytes appeared outside the walls. (4)While four layers of the retinal vasculature was spreading to the ora serrata,the glial limitans was formed outside the endothelial cells by the processes of astrocytes and Muuml;ller cells. CONCLUSIONS:Comparing with the adults,certain de fleieneies of the structure of the retinal vessels exisl in the human fetus,and tile endnthelial cells in the retina of the full lerm fetus arc still in proliferation and migration. （Chin J Ocul Fundus Dis,1997,13:153-156）