| Objectives To study the effect and the therapeutically role of PEDF intravitreally injected in mice with retinal neovascularization.Methods (1)Thirty six one-week-old Kunming mice were randomly divided into four groups:normal control group, group with high oxygen exposure,group injected with PEDF and 0.9%NaCl injected group.The normal group were fed in the normal environment.The other groups were exposed to 75% oxygen to establish a model of retinal neovascularization.Mice in normal group did not receive any treatment. Mice in PEDF group were given an intravitreal injection of 1 ul of PEDF and the same volume of 0.9%NaCl was injected into 0.9%NaCl group mice as a control.Two mice(one twelve-day-old mice and one seventeen-day-old mice)were selected randomly from each group,and retinal flatmount was used to observed the changes of retinal vessels.(2)The other mice were sacrificed on 17-day,the eyes were enucleated for histological examination using light and electron microscopy.(3)The effect of PEDF on retinal neovascularization were evaluated by counting the endotheliocyte nuclei of new vessels extending from retina to vitreous in the retinal tissue-slice under the light microscope..Immunocytochemical method was used to identify the cells extending from retina to vitreous by using an endothelial cell-specific antibody CD31.The change of retinal ultrastructure was observd under the electron microscopy.Results (1)Constriction and occlusion of the retinal blood vessels and decrease in perfusion were found under the hyperoxia condition ,and dilation and proliferation of blood vessels were found under the relatively hypoxia status.Regular distribution and reduced density of the rtinal blood vessels in the treatment eyes of PEDF group were found in retinal flatmount.(2)HE staining: Compared with normal control group.the number of the endotheliocyte nuclei of new vessels extending from retina to vitreous in the hyperoxia and 0.9%NaCL group was more (p<0.05). The number of the endotheliocyte nuclei of new vessels in the PEDF group was much less than the hyperoxia and 0.9%NaCL group (p<0.05) (3)Immunocytochemical staining showed that the cells extending from retina to vitreous were endotheliocytes. (4)Electron microscopy showed hypoxia caused the damage abated considerably after the mice were treated by the PEDF. There were no toxic response in the tissue slice.Conclusion Intravitreal injection of PEDF may suppress the retinalneovascularization in the mice oxygen model and provide some protection from the damage of retinal ultrastructure.. |
