中文摘要：

目的：初步研究牙龈卟啉单胞菌脂多糖（P.gingivalis,P.g-LPS）对人脐静脉细胞融合细胞株EA.hy926一氧化氮合酶（NOS）基因表达的影响,并探讨一氧化氮（NO）释放量与细胞凋亡间的关系。方法：体外培养EA.hy926细胞,选择不同浓度P.g-LPS（10、100、1000μg/m L）诱导刺激,经过不同时间检测其诱导型一氧化氮合酶（iNOS）和内皮型一氧化氮合酶（eNOS）mRNA表达水平、释放的NO量及相应细胞凋亡水平。结果：P.g-LPS诱导EA.hy926细胞iNOS mRNA表达水平在1 h即可升高,4、12 h持续高表达,24 h表达水平回落,但仍高于空白组水平;eNOS mRNA表达水平则时持续下降。不同时间和浓度的P.g-LPS刺激诱导后NO产生量均升高。P.g-LPS诱导EA.hy926细胞,4 h开始出现早期凋亡增加,随后凋亡水平逐渐升高,4、12、24 h凋亡水平均高于空白组。结论：P.g-LPS浓度和时间依赖性地抑制EA.hy926细胞中eNOS mRNA的表达,促进iNOS mRNA的表达。P.g-LPS可能诱导EA.hy926细胞对NOS/NO的调控从而促进细胞凋亡。

英文摘要：

AIM： To study the influences of P. gingivalis lipopolysaccharide（ P. g-LPS） on oxide synthase（ NOS） gene expression,nitric oxide（ NO） release and apoptosis of EA. hy926 cells. METHODS： The EA. hy926 cells were cultured in vitro and treated with P. g-LPS at 10 μg / m L,100 μg / m L and 1 000 μg / m L respectively. The mRNA expression of iNOS and e NOS,NO release and apoptosis were detected after different time periods of treatment.RESULTS： After P. g-LPS induction of EA. hy926 cells,i NOS mRNA level increased 1 h after treatment,remained stable until 12 h,and declined after 24 h without backing to that of the control group. e NOS mRNA level was decreased by P. g- LPS treatment. P. g- LPS of different concentrations at different treatment periods induced NO release. Apoptosis of EA. hy926 cells appeared after 4 h P. g-LPS treatment,and the apoptosis rate in P. g-LPS groups was higher than that of the control group at 4 h,12 h and 24 h. CONCLUSION： P. g-LPS may upregulate of i NOS mRNA and downregulate e NOS mRNA of of EA. hy926 cells in a dose- dependent manner. P. g- LPS can promote EA. hy926 cell apoptosis through NOS / NO regulation.