4 resultados para L-NAME

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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We investigated the effects of Ginsenoside R-e on human sperm motility in fertile and asthenozoospermic infertile individuals in vitro and the mechanism by which the Ginsenosides play their roles. The semen samples were obtained from 10 fertile volunteers and 10 asthenozoospermic infertile patients. Spermatozoa were separated by Percoll and incubated with 0, 1, 10 or 100 mu M of Ginsenoside R-e. Total sperm motility and progressive motility were measured by computer-aided sperm analyzer (CASA). Nitric oxide synthase (NOS) activity was determined by the H-3-arginine to H-3-citrulline conversion assay, and the NOS protein was examined by the Western blot analysis. The production of sperm nitric oxide (NO) was detected using the Griess reaction. The results showed that Ginsenoside R-e significantly enhanced both fertile and infertile sperm motility, NOS activity and NO production in a concentration-dependent manner. Sodium nitroprusside (SNP, 100 nM), a NO donor, mimicked the effects of Ginsenoside R-e. And pretreatment with a NOS inhibitor N-omega-Nitro-L-arginine methyl ester (L-NAME, 100 mu M) or a NO scavenger N-Acetyl-L-cysteine (LNAC, 1 mM) completely blocked the effects of Ginsenoside R-e. Data suggested that Ginsenoside R-e is beneficial to sperm motility, and that induction of NOS to increase NO production may be involved in this benefit.

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目的:1、研究一氧化氮(NO)介导的神经胶质瘤细胞对重离子辐射抗性;2、研究小鼠大脑受重离子辐照后的损伤修复;3、为了更好的研究小鼠大脑受重离子布拉格(Bragg)峰区辐照后的损伤修复,设计并制造了旋转轮状降能装置。材料与方法:1、采用兰州重离子研究装置(HIRFL)加速的碳离子束辐照人类神经胶质瘤三种基因型细胞株:野生型神经胶质瘤细胞(A172),带绿色荧光蛋白基因的神经胶质瘤细胞(EA172)和带诱导型一氧化氮合酶基因(iNOS)的神经胶质瘤细胞(iA172),以及一种加了一氧化氮合酶抑制剂(L-NAME)的A172细胞(L-NAME-A172)。分别利用化学法、流式细胞术和MTT法检测三种神经胶质瘤细胞中NO、谷胱甘肽(GSH)的含量,以及它们的细胞周期变化和辐照后存活状况。2、利用不同剂量的碳离子束辐照昆明小鼠全脑,采用八臂迷宫检测随时间推移及训练次数的增加小鼠记忆损伤恢复情况。3、采用蒙特卡罗法和模拟退火法设计制造了一个有机玻璃材料的旋转降能装置。结果:1、NO和GSH在iA172细胞中的含量比A172和EA172中显著要高;辐照后24小时,观察到A172和EA172细胞发生周期阻滞即细胞阻滞于G2/M期,而这种现象没有在iA172细胞中观察到,并且iA172在接受同样辐射刺激后,细胞存活率显著高于其它三个细胞株。2、动物实验表明,在0-2Gy的碳离子辐照在短期内影响小鼠的记忆,经过一定时间后,这种影响得到恢复。3、物理实验显示,降能装置的实验数据与理论计算相符。结论:在低剂量的重离子坪区辐射条件下,一定浓度的NO可以使神经胶质瘤细胞产生辐射抗性。低剂量的重离子辐射致脑损伤可以得到很快的修复