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Objective To explore the protecting mechanism of erythropoietin (EPO) on learning and memory of Alzheimer disease (AD) rats. Methods The AD model was made by injected into rat hippocampal CA1 subregion with amyloid beta-protein(Aβ). Male Spraque-Dawley rats were as the experimental objects, which were randomly separated into 3 groups including Sham, Saline control and EPO treatment. After Aβ was injected into rats hippocampal CA1 subregion ,saline or EPO was respectively injected into the lateral ventricle of rats,with help of stereotaxic coordinates, upon the designed conditions. Hippocampal CA1 subregion Bcl-xl expression changes were observed 24 hours after the operation, and learning and memory abilities were checked 4 weeks after the operation. Results 24 hours after the operation Bcl-xl expression in the EPO group and the Saline group was less than the Sham control ,while Bcl-xl positive cells( 100.42 ± 12.43/field) in the EPO group were more than in the Saline group( 82.06 ± 19.68/field ) (P ＜ 0. 05 ). 4 weeks after the operation learning ability in the EPO group ( 20.38 ± 5.88 ) was better than Saline group ( 25.50 - 3.25 ) (P ＜ 0. 05 ), and memory ability in the EPO group (4.75 ± 1.75 ) was better than the Saline group(2.88 ± 1.55 )(P ＜ 0.05 ). Conclusion EPO could improve the learning and memory abilities in the model rats,and it could be related with EPO restraining Bcl-xl expression decreasing.
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The effects of ovariectomy (OVX) an d pinealectomy (PX) on apoptosis of cingulated gyrus cell in rats were investiga ted. The results suggest that OVX or PX could induce apoptosis in cingulated gyr us cells, the effect by PX is more serious than that by OVX, and combining effec t of 2 operations is more serious than either effect alone. The effects of OVX a nd PX on cell apoptosis are not related to glial cells.
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Objective To investigate the role of nitric oxide synthase (NOS) in neurotoxic mechanisms of beta amyloid (A?) and the pathogenesis of Alzheimer′s disease (AD). Methods 35 adult rats were divided into 3 groups: normal control,saline injection,and A? 1 40 injection groups A? 1 40 was initially solubilized in saline (10?g/?l) and incubated for at least 1 week before use 1?l incubated A? 1 40 or saline were injected into dorsal blade of dentate gyrus in right hippocampus of rats Immunohistochemical assay of neuronal NOS (nNOS) and inducible NOS (iNOS) was performed at the 2 nd,10 th,and 30 th day after A? 1 40 or saline injection. Results The nNOS like immunoreactivity (nNOSLIR) neurons were found in different brain regions such as cortex,striatum and hippocampus of normal rats,and the number of neurons in dentate gyrus was 8 96?0 31 The number and configuration of nNOSLIR neurons were found without changes after saline injection (8 97?0 29) At 2,10,and 30 d after A? 1 40 injection,the number of nNOS neurons at the site around injection was significantly reduced (3 13?0 27,2 89?0 19 and 2 91?0 25 respectively),but there were no notable differences at these three experimental time points iNOS like immunoreactivity (iNOSLIR) cells were not found in any brain region of normal or saline injected rats After A? 1 40 injection,a large percentage of glia (mainly were astrocytes) had an activated morphological change and showed a strong iNOSLIR around the injection site The responded areas with these cells were 0 905?0 082,0 962?0 161 and 0 935?0 125 mm 2 respectively at 2,10 and 30 day after A? 1 40 injection,but there appeared no significant differences among them. Conclusions The results demonstrate that intrahippocampal injection of A? 1 40 may result in a significant loss of nNOS neurons and induce a considerable expression of iNOS in astrocytes,indicating that NOS may play an important role in neurotoxic mechanisms of A? and the pathogenesis of AD
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0.05).Conclusion The reduction of neoronal proliferation in dentate gyrus may be responsible for the damage of learning and memory ability in aged rats.
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AIM:To study the induction of apoptosis of pheochromocytoma (PC12) cell by L - dopa and the clinical significance. METHODS: Using PC12 cells as the medel of dopaminergic neurons,in addition to electron microscopy, agarose gel electrophoresis and flow cytometry, the apoptosis ratio by L - dopa and the effect of antioxi- dant glutathione on PC12 cells were observed. RESULTS: Treabent of PC12 cells with L - dopa in concentrations of 50 ?mol/L, 100?mol/L and 150 ?mol/L respectively for 24 hours, results revealed that the apoptosis ratio was 12. 8%, 24.4%, 37. 2%, respectively, which is in cobant with fragment pragment propartions of agarose gel electrophoresis, mere higher than that of control(2. 3% ) (P 0 .05). CONCLUTION: Induction of apoptosis by L - dopa could be inhibited by glutathione, and oxidative damage may be involved in the pathophysiology of dopaminergic neurons death after long - term treat- ment of L - dopa.