Department of Neurology, Affiliated Hospital of Taishan Medical University, Taian 271000, Shandong Province, China；Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei Province, China
BACKGROUND: Parkinson disease is neurodegenerative disorders, characterized by a progressive and selective degeneration of nigrostriatal dopaminergic pathway. Its main clinical symptoms include bradykinesia, rigidity, rest tremor and disturbances in balance. Levodopa (L-DOPA) is the 'gold standard' for the symptomatic treat ment of Parkinson disease, but L-DOPA is toxic to dopaminergic neurons and the chronic administration of L-DOPA often causes the side effects of motor such as 'on-off ', etc....更多
BACKGROUND: Parkinson disease is neurodegenerative disorders, characterized by a progressive and selective degeneration of nigrostriatal dopaminergic pathway. Its main clinical symptoms include bradykinesia, rigidity, rest tremor and disturbances in balance. Levodopa (L-DOPA) is the 'gold standard' for the symptomatic treat ment of Parkinson disease, but L-DOPA is toxic to dopaminergic neurons and the chronic administration of L-DOPA often causes the side effects of motor such as 'on-off ', etc., and its mechanism still has not been completely clarified.OBJECTIVE: To observe the changes of the content of glutathione (GSH), activities of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) and content of malondialdehyde (MDA) in glia-containing mesencephalic culture fluid after L-DOPA of different concentrations were added.DESIGN: A comparative observation.SETTINGS: Department of Neurology, Affiliated Hospital of Taishan Medical University; Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology. MATERIALS: The experiment was carried out in the Basic Research Institute, Taishan Medical University from December 2003 to September 2004. Ten postnatal newborn SD rats (within 2 days) were selected, either male or female. Fetal bovine serum (DMEM/F12) was from Gibco Company; L-DOPA and glial fibrillary acidic protein (GFAP) from Sigma Company. Kits for determination of GSH, GSH-Px, SOD and MDA were purchased from Nanjing Jiancheng Bioengineering Research Institute.METHODS : Glia-containing mesencephalic culture fluid were placed in 24-well culture plate, and L-DOPA of 50, 100 and 500 μmol/L was added to each group, the blank control group was also set. The glia-containing mesencephalic culture fluid selected at 4, 24, 48 and 72 hours respectively to determine the GSH content with colorimetric quantitative technique, GSH-Px activity with colorimetric method, SOD activity with xanthine oxidase method and MDA content with thiol-barbituric acid method.MAIN OUTCOME MEASURES: GSH and MDA contents, GSH-Px and SOD activities in the glia-containing mesencephalic culture fluid at 4, 24, 48 and 72 hours after L-DOPA of different concentrations were added. RESULTS: In the glia-containing mesencephalic culture fluid after 100 μmol/L L-DOPA was added for 24, 48 and 72 hours, the GSH contents were lower than those in the blank control group [(174.14±39.28), (161.55± 40.79), (144.97±57.59) mg/L; (220.66±32.61), (221.10±32.98), (220.43±31.98) mg/L, P ＜ 0.05]; The GSH-Px activities were lower than those in the blank control group [(4.03±1.05), (3.99±1.12), (3.47±1.00) μmol/L; (5.45±1.14), (5.69±1.21), (5.49±1.28) μmol/L, P ＜ 0.05]; The SOD activities were also lower than those in the blank control group [(42.02±5.08), (39.38±5.34), (38.87±5.75) kNU/L; (51.35±8.87), (51.78±8.96), (50.99± 9.09) kNU/L, P ＜ 0.05]; Whereas the MDA contents were higher than those in the blank control group [(3.51 ± 1.05), (3.99±1.03), (4.45±1.58) μmol/L; (2.09±1.13), (2.18±1.29), (2.01±1.05) μ mol/L, P＜ 0.05]. In the glia-containing mesencephalic culture fluid after 100 μmol/L L-DOPA was added for 4, 24, 48 and 72 hours, the GSH contents were (172.27±26.07), 140.15±61.44), (137.30±50.87), (121.09±66.07) mg/L, the GSH-Px activities were (3.89±1.20), (3.56±1.23), (3.38±1.18), (3.01±1.09) μmol/L, the SOD activities were (38.18±6.75),(35.23±7.85), (4.59±1.24), (31.42±7.01) kNU/L, which were all lower than those in the blank control group (P ＜ 0.05-0.01); The MDA contents were (3.65±0.86), (3.87±1.14), (4.59±1.24), (4.79±1.32) μmol/L, which were higher than those in the blank control group (P ＜ 0.05-0.01). In the glia-containing mesencephalic culture fluid added by 50 μmol/L L-DOPA, the GSH and MDA contents, GSH-Px and SOD activities at each time point were all close to those in the blank control group (P＞ 0.05).CONCLUSTON: L-DOPA of certain concentration can destroy the dynamical balance of free radicals in glia-containing mesencephalic culture fluid, and accelerate the degeneration of neurons, which are in concentrationand time-dependent manners.收起
