Deng Yan, Fang Weirong, Li Yunman, Cen Juan, Fang Fang, Lv Peng, Gong Shubo, Mao Lishun
Department of Physiology, China Pharmaceutical University, Nanjing, Jiangsu 210009, PR China.
Eur J Pharmacol. 2009 Aug 15;616(1-3):43-7. doi: 10.1016/j.ejphar.2009.06.017. Epub 2009 Jun 23.
Hypoxia and reoxygenation set in motion a series of events, including blood-brain barrier breakdown. We examined the content and effect of platelet-activating factor (PAF), which was increased in the rat brain microvessel endothelial cells (RBMECs) during hypoxia and reoxygenation. MTT method was used to assay cell damage; ELISA analysis was used to estimate PAF release after hypoxia and reoxygenation injury; and RT-PCR and Western blotting method were used to assess gene and protein expressions of inducible nitric-oxide synthase (iNOS) in RBMECs under PAF damage. PAF affected intracellular free Ca(2+) levels, increasing Ca(2+), which caused up-regulation of iNOS. We also examined the blood-brain barrier protective effect of XQ-1H, a novel ginkgolide B derivative. Pretreatment with XQ-1H (10 microM and 3 microM) for 24 h significantly antagonized PAF receptor and inhibited the increase in intracellular calcium concentration and the up-regulation of iNOS in response to PAF under hypoxia and reoxygenation in vitro.
缺氧和复氧引发了一系列事件，包括血脑屏障破坏。我们检测了血小板活化因子（PAF）的含量及作用，其在缺氧和复氧过程中大鼠脑微血管内皮细胞（RBMECs）内含量增加。采用MTT法检测细胞损伤；采用ELISA分析法评估缺氧和复氧损伤后PAF的释放；采用RT-PCR和蛋白质印迹法评估PAF损伤下RBMECs中诱导型一氧化氮合酶（iNOS）的基因和蛋白表达。PAF影响细胞内游离钙离子水平，使[Ca²⁺]i升高，导致iNOS上调。我们还检测了新型银杏内酯B衍生物XQ-1H对血脑屏障的保护作用。在体外缺氧和复氧条件下，用XQ-1H（10微摩尔和3微摩尔）预处理24小时可显著拮抗PAF受体，并抑制细胞内钙浓度升高以及PAF诱导的iNOS上调。
