Influences of levodopa and cytidine diphosphate choline on the expression of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid GluR2 in visual cortex of monocular deprivation rats / 中华实验眼科杂志

Background Research demonstrated that alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid GluR2 (AMPA-GluR2) is associated with amblyopia.It has been shown that levodopa and cytidine diphosphate choline can improve visual function of amblyopic children,but the mechanism is unclear.Objective This study was to explore the possible effects of levodopa and cytidine diphosphate choline on amblyopia.Methods Monocular deprivation (MD) animal models were created in 60 2-week-old SD rats by monolateral eyelid suturing and observed for 31 days and reared in natural light together with 15 other matched normal healthy SD rats.The models were randomly divided into the MD group,levodopa group,cytidine diphosphate choline group and normal saline control group,with 15 rats for each group.40 mg/kg of levodopa,80 mg/kg of cytidine diphosphate choline,I ml normal saline were given to the rats,respectively,for 28 consecutive days.Expressions of the AMPA-CluR2 protein and AMPA-CluR2 mRNA in the rat visual cortex were detected by immunohistochemistry,Western blot and real-time fluorescence quantitative PCR.Use of the animals followed the Regulations for the Administration of Affairs Concerning Experimental Animals by State Science and Technology Commission.Results The expression values of the AMPA-GluR2 protein (AMPA-GluR2/β-actin) and AMPA-GluR2 mRNA (2-△△Ct) were significantly lower in the MD group than those of the normal control group (protein:0.32 ± 0.02 vs.0.64 ± 0.05,t =13.287,P＜0.05 ;mRNA:0.30±0.01 vs.0.84±0.03,t=38.184,P＜0.05).Those in the levodopa group were significantly increased in comparison with the normal saline solution group (protein:0.59 ±0.04 vs.0.33 ±0.03,t =11.628,P＜0.05 ; mRNA:0.71±0.06 vs.0.33 ±0.02,t =13.435,P＜0.05).The expression values of the AMPA-GluR2 protein and AMPA-GluR2 mRNA were significantly increased in the cytidine diphosphate choline group compared with the normal saline solution group (protein:0.52 ± 0.04 vs.0.33 ± 0.03,t =8.497,P ＜ 0.05 ; mRNA:0.48± 0.04 vs.0.33 ± 0.02,t =7.500,P＜0.05).Conclusions AMPA-GluR2 is associated with the plasticity of visual development.Levodopa and cytidine diphosphate choline may improve visual function by down-regulating the expression of AMPA-GluR2 in the visual cortex.

Effect of curcumin on AMPA and kainate receptor-mediated calcium influx in cultured rat hippocampal neurons / 中华神经医学杂志

Objective To investigate the effect of curcumin on alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and kainate (KA) receptor-mediated calcium influx in cultured rat hippocampal neurons. Methods The hippocampal neurons from SD rat embryos (17 days old) were cultured for 9 days, and fluorescent calcium chelator and confocal microscopy calcium imaging were used to observe the changes in intracellular free calcium in the neurons following stimulation with 100 μmol/L KA. The effect of curcumin pretreatment at different concentrations (10, 30, 50, 100, 200 and 300 μmol/L) for 30 min on 100 μmol/L KA-induced intracellular calcium changes in the neurons were evaluated, and the effect of 15 μmol/L curcumin on intracellular calcium in the neurons stimulated with 10, 30, 50, 100, 200 and 300 μmol/L KA were also assessed. Cobalt staining was used to examine the expression of calcium permeable AMPA/KA channel in the hippocampal neurons treated with 30 and 100 μmol/L KA. Results Curcumin pretreatment at different concentrations for 30 min significantly relieved the elevation of flee calcium concentration induced by 100 or 30 μmol/L KA (P<0.05), and the effect was especially obvious with 15 μmol/L KA curcumin. Both 30 and 100 μmol/L KA increased the ratio of cobalt staining-positive hippocampal neurons, and curcumin pretreatment at 15 μmol/L, but not at 5 or 30 μmol/L, significantly reduced the ratio of the positive neurons (P<0.05). Conclusion Curcumin at appropriate concentrations can modulate calcium influx mediated by AMPA and KA in cultured rat hippocampal neurons, which might be one of the anti-epileptic mechanisms of curcumin

The effects of propofol on neurotoxicity induced by alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid in rat mixed cortical cultures / 대한마취과학회지

BACKGROUND: The pattern of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-mediated neurotoxicity (necrosis vs apoptosis) and the neuroprotective effect of propofol on AMPA-mediated neurotoxicity are still unclear. METHODS: Thirteen-day-old primary rat mixed cortical cultures were used. To measure the neuroprotective effect of propofol, AMPA (50micrometer), AMPA (50micrometer) plus propofol (0.1, 1, 25, 50micrometer), AMPA (50micrometer) plus DMSO, propofol (50micrometer) and DMSO were administered (n = 45). Seventy-two h later, surviving cells were counted using trypan blue staining and were converted to cell death rate (CDR). To measure the effect of propofol (50micrometer) on AMPA (50micrometer)-induced apoptosis, a triple stain was done. In a fixed field (x400), the number of neuronal cells stained by neuronal nuclei (NeuN) and Hoechst staining and apoptotic cells stained by terminal deoxynucleotidyl transferase mediated dUTP nick-end-labeling (TUNEL) assays were counted. Apoptotic cell rates (ACR) were also calculated. Statistical analyses were performed using one way-analysis of variance followed by Bonferroni's test. P < 0.05 was considered statistically significant. RESULTS: AMPA (50micrometer) stimulation demonstrated 49.3% CDR, and adding propofol 50micrometer decreased CDR to 29.4% (P < 0.05). In the TUNEL assay, cells with no drug treatment demonstrated 12.3% ACR and 50micrometer AMPA increased ACR to 28% (P < 0.05). Adding 50micrometer propofol to AMPA decreased the ACR to 20.1% (P < 0.05). CONCLUSIONS: Propofol (50micrometer) had neuroprotective effects against AMPA (50micrometer)-induced cell death by reducing apoptosis.

The effects of propofol on neurotoxicity induced by alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid in rat mixed cortical cultures / 대한마취과학회지

BACKGROUND: The pattern of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-mediated neurotoxicity (necrosis vs apoptosis) and the neuroprotective effect of propofol on AMPA-mediated neurotoxicity are still unclear. METHODS: Thirteen-day-old primary rat mixed cortical cultures were used. To measure the neuroprotective effect of propofol, AMPA (50micrometer), AMPA (50micrometer) plus propofol (0.1, 1, 25, 50micrometer), AMPA (50micrometer) plus DMSO, propofol (50micrometer) and DMSO were administered (n = 45). Seventy-two h later, surviving cells were counted using trypan blue staining and were converted to cell death rate (CDR). To measure the effect of propofol (50micrometer) on AMPA (50micrometer)-induced apoptosis, a triple stain was done. In a fixed field (x400), the number of neuronal cells stained by neuronal nuclei (NeuN) and Hoechst staining and apoptotic cells stained by terminal deoxynucleotidyl transferase mediated dUTP nick-end-labeling (TUNEL) assays were counted. Apoptotic cell rates (ACR) were also calculated. Statistical analyses were performed using one way-analysis of variance followed by Bonferroni's test. P < 0.05 was considered statistically significant. RESULTS: AMPA (50micrometer) stimulation demonstrated 49.3% CDR, and adding propofol 50micrometer decreased CDR to 29.4% (P < 0.05). In the TUNEL assay, cells with no drug treatment demonstrated 12.3% ACR and 50micrometer AMPA increased ACR to 28% (P < 0.05). Adding 50micrometer propofol to AMPA decreased the ACR to 20.1% (P < 0.05). CONCLUSIONS: Propofol (50micrometer) had neuroprotective effects against AMPA (50micrometer)-induced cell death by reducing apoptosis.