ObjectiveTo observe the inhibitory effect of endostatin (ES) on oxygen-induced retinal neovascularization.MethodsThirtyfour 7-day-old C57BL/6J mice were randomly divided into 3 groups: oxygen-exposed group (12 mice), ES group (12 mice) and the control group (8 mice). The mice in oxygen-exposed and ES group were exposed to (75±5)％ oxygen for 5 days and then back to the normal air. In ES group, 1 μg ES endostatin were injected into vitreous in one eye, while PBS was injected into the other eye as the control 12 and 36 hours after being exposed to oxygen. The mice in the control group were fed in normal circumstance. The changes of retinal neovascularization was examined by fluorescence angiography with fluorescein isothiocyanatedextran. The number of endothelial cells breaking through the internal limiting membrane (ILM) was counted and the inhibitory effects of ES on retinal neovascularization was observed.ResultsCompared with the oxygen-exposed group, the branches of retinal vessels went normal without any un-perfused area in ES group. The number of nuclei of endothelial cells breaking through ILM on each retinal crosssection decreased to (5.39±1.52), which differed much from that in the oxygen-exposed group (22.56±2.13) (plt;0.001).ConclusionES can effectively inhibit the formation of retinal neovascularization in rats and might be a new path of the treatment for proliferative retinopathy.(Chin J Ocul Fundus Dis, 2005,21:314-317)
目的:研究离体肝脏缺血再灌注期间丝裂原活化蛋白激酶(mitogen activated protein kinase,p38MAPK)信号转导途径对肿瘤坏死因子α (tumor necrosis factor α,TNFα )mRNA表达的影响。方法:建立兔离体肝脏缺血再灌注模型,对照组(n=12)灌注液中不加特异性p38MAPK抑制剂SB202190,抑制组(n=12)灌注液中加入SB202190(浓度为3μmol/L)。分别于肝脏离体前,冷保存末,再灌注10min、30min、60min及120min时获取离体肝组织标本。应用Western-blot法及免疫沉淀法检测离体肝组织中p38MAPK表达的水平及活性,RT-PCR法检测TNF-α-mRNA表达水平。结果:对照组p38MAPK活性在冷保存末及再灌注10min、30min、60min均较离体前和再灌注120min显著升高(Plt;0.01),也显著高于同时相点的抑制组(Plt;0.01);抑制组p38MAPK活性在组内各时相点的变化无显著性差异(Pgt;0.05)。两组肝脏于离体前、冷保存末及再灌注10min及30min,肝组织中仅有少量TNF-α mRNA表达,组间及组内比较无显著性差异(Pgt;0.05);至再灌注60min及120min,对照组TNF-α mRNA的表达水平显著性高于组内其它时相点(Plt;0.01),而抑制组虽然也显著高于组内其它时相点(Plt;0.05),但却显著性低于同时相点对照组的表达水平(Plt;0.01)。离体再灌注期间供肝组织中p38MAPK活性与供肝组织内TNF-α mRNA的表达水平呈显著性正相关(r=0.996,Plt;0.01)。结论:p38MAPK对TNF-α生成的调节作用层次可能在转录水平,提示p38MAPK信号转导途径对TNF-α mRNA的调节可能是导致离体肝脏缺血再灌注损伤的重要机制之一。
目的:研究离体肝脏缺血再灌注期间丝裂原活化蛋白激酶(mitogen activated protein kinase,p38MAPK)信号转导途径对细胞间黏附分子1(intercellular adhesion molecular 1,ICAM1)mRNA表达的影响。方法:建立兔离体肝脏缺血再灌注模型,对照组(n=12):灌注液中不加特异性p38MAPK抑制剂SB202190,抑制组(n=12):灌注液中加入SB202190(浓度为3μmol/L)。于肝脏离体前,冷保存末,再灌注10min、30min、60min及120min时获取离体肝组织标本。分别应用Western-blot法及免疫沉淀法检测离体肝组织中p38MAPK表达的水平及活性,原位杂交法检测ICAM1 mRNA表达水平。结果:与离体前相较,对照组p38MAPK活性在冷保存末及再灌注10min、30min、60min显著性增高(Plt;0.01),而再灌注120min时活性与离体前相较无明显差异(Pgt;0.05);抑制组p38MAPK活性在各时相点的变化无显著性差异(Pgt;0.05),除离体前及再灌注120min两组肝脏的p38MAPK活性无显著性差异外,其余各时相点p38MAPK活性均显著性低于对照组(Plt;0.01)。离体前、冷保存末及再灌注10min及30min时,两组肝组织中仅有少量ICAM1 mRNA表达,组间及组内比较无显著性差异(Pgt;0.05);至再灌注60min及120min,对照组ICAM1 mRNA的表达水平显著性高于组内其它时相点(Plt;0.01),而抑制组虽然也显著高于组内其它时相点(Plt;0.05),但却显著性低于同时相点对照组的表达水平(Plt;0.01)。离体再灌注期间供肝组织中p38MAPK活性与供肝组织内ICAM1 mRNA的表达水平呈显著性正相关(r=0.985,Plt;0.01)。结论:p38MAPK对ICAM1生成的调节作用层次可能在转录水平,提示p38MAPK信号转导途径对ICAM1 mRNA的调节可能是导致离体肝脏缺血再灌注损伤的重要机制之一。