| Objective To made the argon laser-induced model of choroidal neovascularization (CNV) in Long-evants rats. To object the expression of mmp-2 and VEGF in the choroid and retina of the CNV animal model.To investigate the effects and mechanism of Captopril on choroidal neovascularization (CNV).Methods Select healthy adult Long-Evants rats to photocoagulate in retinal by the argon laser to induce the CNV animal model. The fundus fluorescein angiography (FFA) were performed,then eyes of the rats were made into sections after fixed by 4% paraform all over the body on day3,5,7,14,21,28 post-photocoagulating. For judging whether the CNV animal model were made successfully, some sections were stained by hemotoxylin and dosin(HE)and chorioretina tissue structure were observed by the light microscope.Others were used to do immunofluorescence and immunohistochemistry to survey the expression of mmp-2 and VEGF.After making CNV animal model,select healthy adult Long-Evants rats as before, The fundus fluorescein angiography (FFA) were performed,then eyes of the CNV rats were made into sections after fixed by 4% paraform all over the body on day3,5,7,14,21,28 post-photocoagulating. Chorioretina sections were stained by hemotoxylin and dosin(HE)and observed the tissue structure by the light microscope;the expression of mmp-2 in retina pigment epithelium(RPE)layer and the expression of VEGF in retinal tissue were detected by immunofluorescence or immunohistochemistry differently.Results:1. Results of making CNV animal model:1.1 FFA: Some spots appeared dropsy and fluorescein coloring on day 3 post-photocoagulating. Fluorescein leaking were found on day 7 ,which indicated that CNV has fomed. CNV reached the peak on day 21.1.2 Observing sections by the light microscope: The retina appeared dropsy,cell alinement disorder etal on 3 day. Lots of fibroblast and few CNV were found on 7 day . CNV reached the peak on day 21.2. Regularity of MMP-2 and VEGF in retina of the CNV model:2.1 Observing expression of MMP-2 by immunofluorescence: the positive staining appeared in RPE layer on day 3,and reached peak on day 5 ,then decreased gradually.In naomal retina tissue.MMp-2 were not found to express.2.2 Observing expression of VEGF by immunohistochemistry: the positive expression of VEGF was observed in retina on day 14 and reached peak on day 21 .VEGF expressed very weakly in normal retina tissue.3. Results of captopril intervention:3.1 FFA: The number of spots appearing fluorescein leaking in retina of the captopril group(group C) was much fewer than that of control group (group B) in erery time point. CNV were found decreasing.3.2 Observing sections by the light microscope: Compared to control group (group B), the pathological changes in retina of the captopril group(group C) were lessened obviously.3.3 Observing expression of mmp-2 by immunofluorescence:The mean energy of positive expression of mmp-2 in captopril group(group C) was more weakened than that in group B(p<0.05) on every time point.3.4 Observing expression of VEGF by immunohistochemistry:The positive expression of VEGF in captopril group(group C)was more weakened than that in group B(p<0.05) on every time point.Conclusions:1. The way that using argon laser to photocoagulate retina of the Long-Evants rat to acquire the CNV animal model is feasibility and fast.2. Compared to normal retina tissue, the positive expression of mmp-2 and VEGF was strengthened remarkably.3. According to the rules of expression of mmp-2 and VEGF,the matrix metalloproteinases(MMPs),which palyed an important part of role in the early stage of course of desease,maybe increased the expression of VEGF,which appeared later than mmp-2.The correction between mmp-2 and VEGF needed to be study furtherly.4. Captopril inhibits choroidal neovascularization by reducing expression of mmp-2 and VEGF... |
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