α—硫辛酸对6—羟多巴胺诱导的PC12细胞凋亡的影响

PC12 cell line, a clonal cell line derived from a pheochromocytoma of rat adrenal medulla, was used as a model of dopaminergic neuron in vitro to study the effect of alpha-lipoic acid on the 6-OHDA induced apoptosis. The results from MTT method show that 6-OHDA decreased the cell survival rate obviously. Through TUNEL (TdT-mediated dUTP-biotion nick end labeling) and Flow cytometer (FCM) detection, we found that 6-OHDA triggered cell apoptosis and induced necrosis. It was confirmed by the different percentage of cell survival rate and apoptosis concluded from FCM and MTT. alpha-lipoic acid was used as antioxidant to protect the cell from 6-OHDA's injury. The result indicateed that alpha-lipoic acid can partly prevent apoptosis induced by 6-OHDA but fail to prevent necrosis since it can decrease the apoptotic cell from 20.09% to 3.09%, just as increased cell survival rate from 56.8% to 72.6% but can not reach the normal level showed by MTT assay. Biochemical approach showed the cell's antioxidant ability especial for SOD activity and GSH content increased after the treatment of alpha-lipoic acid. The data suggest that alpha-lipoic acid may protect PC12 cells from apoptosis induced by 6-OHDA through the antioxidant path.     

氟的环境地球化学行为及其对生态环境的影响

近几十年来,氟的区域性环境地球化学异常和人为环境污染所导致的植物和人体氟暴露现象引起了广泛关注,世界各国学者对不同环境介质中氟的地球化学行为进行了较为深入的研究,但仍然存在诸多争议和不确定性.本文回顾了近些年来有关氟在大气、水、土壤中的来源、数量、存在形态、迁移转化和控制因素等方面的研究成果,以及氟的地球化学行为与植物和人体氟暴露的关联性,并提出了未来有关氟的环境地球化学行为研究应优先考虑的几个方向.