Objective To investigate the toxicity of copper on MES23.5 dopaminergic cells and the probable mechanisms involved in this process. Methods MES23.5 dopaminergic cells were selected as our experimental model. [3-（4, 5...Objective To investigate the toxicity of copper on MES23.5 dopaminergic cells and the probable mechanisms involved in this process. Methods MES23.5 dopaminergic cells were selected as our experimental model. [3-（4, 5-dimethylthiazol2-yl）-2, 5 diphenyltetrazolium bromide] （MTT） assay was used to detect the influence of copper on the cell viability. The semiquantitative reverse transcription polymerase chain reaction （RT-PCR）, Western blotting and the high performance liquid chromatography-electrochemical detection （HPLC-ECD） have been used to detect the tyrosine hydroxlase （TH） mRNA and protein expression and the dopamine content in MES23.5 cells. The flow cytometry have been used to detect the changes of mitochondrial transmembrane potential. Results 100 and 200 μmol/L copper had no effect on the MES23.5 cell viability, whereas 400 and 800 μmol/L of copper could decrease the cell viability （P 〈 0.01）. Treating cells with 200 μmol/L copper for 24 h decreased the TH mRNA expression, the TH expression and the dopamine content compared with the control （P 〈 0.01, P 〈 0.01, P 〈 0.05, respectively）. Besides, the mitochondrial transmembrane potential also decreased with the treatment of 200 μmol/L copper for 24 h （P 〈 0.01）. Condusion Copper could exert the toxic effects on MES23.5 dopaminergic cells and decrease the cell function. The dysfunction of mitochondria may be the mechanism of this toxicity effect.展开更多
Objective To study the effects of intranigral injection of different doses of CuSO45H2O on dopaminergic neuron in the nigrostriatal system of rats. Methods Wistar rats were divided into four groups, including control ...Objective To study the effects of intranigral injection of different doses of CuSO45H2O on dopaminergic neuron in the nigrostriatal system of rats. Methods Wistar rats were divided into four groups, including control group, 10 nmol, 50 nmol and 200 nmol copper injected into left substantia nigra （SN） groups. Seven days after the intranigral injection of copper, dopamine （DA） contents in the striatum （Str） were measured by high performance lipid chromotophotography （HPLC）; the density of tyrosine hydroxylase （TH） positive axons in the Str was measured by TH staining method; TH and Caspase-3 mRNA expression in the SN were measured by semi-quantitative RT-PCR. We detected the activity of superoxide dismutase （SOD） in the lesioned midbrain of rats using biochemical methods. Results DA and its metabolites contents had no significant difference between control group and low dose （10 nmol） copper group. But from 50 nmol copper group, DA contents in the lesioned sides were reduced with the increase in the copper doses injected, showing a significant linear correlation （F = 34.16, P 〈 0.01）. In the 50 nmol copper group, TH positive axons in the Str decreased compared with those of the control and unlesioned sides （F = 121.9, P 〈 0.01）. In the 50 nmol copper group, TH mRNA expression decreased （t =3.12, P 〈 0.01） while Caspase-3 mRNA expression increased （t =8.96, P 〈 0.01） in the SN compared with the control. SOD activity decreased in the midbmin of rots treated with 50 nmol copper compared with that of the control （t = 2.33, P〈0.01）. Conclusion Copper could induce damage of dopaminergic neurons in the SN of rats through destroying antioxidant defenses and promoting apoptosis.展开更多
文摘Objective To investigate the toxicity of copper on MES23.5 dopaminergic cells and the probable mechanisms involved in this process. Methods MES23.5 dopaminergic cells were selected as our experimental model. [3-（4, 5-dimethylthiazol2-yl）-2, 5 diphenyltetrazolium bromide] （MTT） assay was used to detect the influence of copper on the cell viability. The semiquantitative reverse transcription polymerase chain reaction （RT-PCR）, Western blotting and the high performance liquid chromatography-electrochemical detection （HPLC-ECD） have been used to detect the tyrosine hydroxlase （TH） mRNA and protein expression and the dopamine content in MES23.5 cells. The flow cytometry have been used to detect the changes of mitochondrial transmembrane potential. Results 100 and 200 μmol/L copper had no effect on the MES23.5 cell viability, whereas 400 and 800 μmol/L of copper could decrease the cell viability （P 〈 0.01）. Treating cells with 200 μmol/L copper for 24 h decreased the TH mRNA expression, the TH expression and the dopamine content compared with the control （P 〈 0.01, P 〈 0.01, P 〈 0.05, respectively）. Besides, the mitochondrial transmembrane potential also decreased with the treatment of 200 μmol/L copper for 24 h （P 〈 0.01）. Condusion Copper could exert the toxic effects on MES23.5 dopaminergic cells and decrease the cell function. The dysfunction of mitochondria may be the mechanism of this toxicity effect.
文摘Objective To study the effects of intranigral injection of different doses of CuSO45H2O on dopaminergic neuron in the nigrostriatal system of rats. Methods Wistar rats were divided into four groups, including control group, 10 nmol, 50 nmol and 200 nmol copper injected into left substantia nigra （SN） groups. Seven days after the intranigral injection of copper, dopamine （DA） contents in the striatum （Str） were measured by high performance lipid chromotophotography （HPLC）; the density of tyrosine hydroxylase （TH） positive axons in the Str was measured by TH staining method; TH and Caspase-3 mRNA expression in the SN were measured by semi-quantitative RT-PCR. We detected the activity of superoxide dismutase （SOD） in the lesioned midbrain of rats using biochemical methods. Results DA and its metabolites contents had no significant difference between control group and low dose （10 nmol） copper group. But from 50 nmol copper group, DA contents in the lesioned sides were reduced with the increase in the copper doses injected, showing a significant linear correlation （F = 34.16, P 〈 0.01）. In the 50 nmol copper group, TH positive axons in the Str decreased compared with those of the control and unlesioned sides （F = 121.9, P 〈 0.01）. In the 50 nmol copper group, TH mRNA expression decreased （t =3.12, P 〈 0.01） while Caspase-3 mRNA expression increased （t =8.96, P 〈 0.01） in the SN compared with the control. SOD activity decreased in the midbmin of rots treated with 50 nmol copper compared with that of the control （t = 2.33, P〈0.01）. Conclusion Copper could induce damage of dopaminergic neurons in the SN of rats through destroying antioxidant defenses and promoting apoptosis.
