| PURPOSE:Neovascularization have active effect on wound of organism and ischemia of tissue. It is pathology character of some ocular diseases, such as tumor, diabetic complications and vascular proliferation ophthalmocace. Now the study on inhibition of neovascularization becomes focal point. The aim of this experiment is comparison of inhibitory Effect of endogenous new vessels inhibiting factor kallikrein-binding protein (KBP), and anti-vascular growth factor bevacizumab on choroidal neovascularization.METHODS:1.20 BN rats were photocoagulated eight points around optic papilla using 532nm laser on right eye to induce CNV. The laser spots'parameter were 50 um diameter. The exposure time was 0.10second, and the power was 360 mW.2. Fluorescein angiography was performed in lweek,2week,3week and 4week after laser photocoagulation and the CNV area was measured by FFA. The five rats were sacrificed in lweek,2week,3week and 4week after laser photocoagulation. The eyes were enucleated and processed for ozocerite cut sheet and HE dyeing for histopathologic examination and immunohistochemistry to observe the expression of VEGF protein and PEDF protein in rat retinal and the lesion of CNV.3.45 BN rats were photocoagulated by 532nm laser on right eye to induce CNV model. These rats were divided into three groups:Bevacizumab group, KBP group and control group. After laser photocoagulation one week, bevacizumab group of the rats were received intravitreal injection of Bevacizumab 5μl (25μg/1μl) in right eye, and left eyes were received intravitreal injection of 5μl PBS. KBP group of rats were received intravitreal injection of KBP 5μl (4mg/ml KBP), and the left eyes were received intravitreal injection 5μl deionized water. The control group had no intravitreal injection.4. Fluorescein angiography was performed in lweek,2week and 3week after intravitreal injection and the CNV area was measured by FFA. Then the five rats were sacrificed in lweek,2week and 3week after intravitreal injection. The eyes were enucleated and processed for ozocerite cut sheet and HE dyeing for histopathologic examination and immunohistochemistry in CNV to be observe the expression of VEGF protein and PEDF protein in rat retinal and the lesion of CNV.5. The experimental data were expressed as the mean±S. D. and the statistical significance was determining by variance analysis, SNK test.RESULTS:1. CNV model was built by laser photocoagulation. Fluorescein leakage was observed and confirmed the formation of CNV after laser photocoagulation one week. Fluorescein leakage showed the persistent increase of the CNV development after four weeks and the third week was a peak time.2. VEGF and PEDF expression were mainly observed in the ganglion cells, the inner nuclear layers, the retinal pigment epithelial cells, nuclear layer and lesion of outer nuclear layers after photocoagulation. And the expression of VEGF increase gradually, however the expression of PEDF decrease gradually.3. After intravitreal injection, compared with control group, bevacizumab group and KBP groups were decreasing fluorescein leakage, and have statistical significance (P<0.05). To compare bevacizumab group with KBP group, decreasing fluorescein leakage have no statistical significance(P >0.05) but the mean of fluorescein leakage area of KBP group was lower.4. In the result of immunohistochemistry, compare with control group, bevacizumab group and KBP group were up-regulate the expression of VEGF and down-regulate the expression of PEDF, and have statistical significance (P<0.05). To compare bevacizumab group with KBP group, there were no statistical significance(P>0.05), between these two groups, but the mean IOD of KBP group have better result.CONCLUSION:1.532nm laser photocoagulation can be successfully used to produce CNV experimental model in the BN rat. CNV pathologic structure possesses stability.2. VEGF and PEDF play the important role in CNV development.3. Intravitreal KBP and bevacizumab injection can inhibit the development of CNV. And KBP have better result.
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