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Objective To evaluate the effects of electromagnetic irradiation of 2000 μW/cm2 exposure on mRNA and protein expression levels of immunoreactive protein and mRNA of NMDAR1 in rats hippocampal,and to explore the impaired mechanism of electromagnetic irradiation on learning and memory.Methods Rats were randomly divided into normal control group, sham-radiated group, and 1 h/d, 2 h/d, and 3 h/d radiation groups.The rats in the radiation groups were fixed and recieved microwave exposure of 2000 μW/cm2, then their learning and memory abilities were tested by Morris water maze experiment, the change of NR1 protein in hippocampal neurons of each group of rats was measured with immunohistochmistry and western blot techniques, and the expression of NR1 mRNA in hippocampus was determined by RT-PCR.Results In the water maze test,compared with the normal control group (8.8 ± 1.66 ), the escape latency of three radiated groups rats ( 1 h/d ( 12.29 ±1.36) s,2 h/d ( 17.99 ±2.25) s,and 3 h/d (24.66 ±5.56) s) were significantly longer (P＜0.05).In the radiation group,the hippocampal neurons of rats showed evident reduction in the ratio of NR1 positive cells,irregular,and arrayed in disorder.Moreover,compared with the normal control group ( (0.70 ±0.11 ), (0.68 ±0.11 ) ) ,the expession of NR1 protein ( 1 h/d (0.122 ±0.026) ,2 h/d (0.102 ±0.023) ,and 3 h/d (0.060 ± 0.009) ) and its mRNA ( 1 h/d (0.46 ±0.07) ,2 h/d (0.35 ±0.05) ,and 3 h/d (0.12 ±0.02) ) in hippocampal neurons was significantly decreased (P＜0.05).Among the indicators, there was no significant difference between sham-radiated group and normal control group.Conclusions Electromagnetic irradiation of 2000 μW/cm2 exposure can impair the learning and memory abilities of rats possibly through a mechanism correlated with the lower expression of NR1 protein and its mRNA in hippocampus.
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Objective To observe the effect of buyanghuanwu decoction on expression of immunoreactive protein and mRNA of NMDA receptor 2B subunit in rats hippocampal with vascular dementia to investigate the mechanism of buyanghuanwu decoction. Methods One hundred and forty-four rats were randomly divided into 4 groups: sham-operated group, VD model group,nimodipine group and buyanghuanwu decoction treatment group. The rats models of vascular dementia were built up by four vessels occlusion method. VD rats were treated with in-tragastrical buyanghuanwu decoction suspension (50 pharmacognostic g·kg-1·d-1) and nimodipine suspension (20 mg·kg-1·d-1) for 30 days. The learning and memory abilities were evaluated by Morris water maze tests. The change of NR2B protein in hippocampal of each group of rats were measured with immunohistochemistry and Western blot techniques and the expression of NR2B mRNA in hippocampus were observed by real-time fluorescence quantitative PCR techniques. Results Water maze tests,compared with sham-operated group((24. 18 ± 7.90)s,(7.99 ±1.32)/min) ,the escape latency(51. 25 ±18.28)s to explore the extension and the average spatial probe number ((5. 26 ±0. 74)/min) reduced in VD model group (P < 0. 05). Buyanghuanwu decoction ((25.91 ±9.56)s,(7. 52 ± 1. 27)/min) had significantly improved the above-mentioned rat model of learning and memory performance (P<0.05). There was no significant difference among sham-operated group,nimodipine group and buyanghuanwu decoction treatment group (P>0. 05). Similarly,as compared rats with sham-operated group(0.71 ±0.13), (5887 ±501), the expression of NR2B protein (0. 33 ± 0. 06) and its mRNA(593 ±53) were apparently decreased in VD rats (P< 0.05). The expression of NR2B protein(0.66 ±0. 11) and its mRNA (5692 ±482) in neuron of hippocampus were increased by buyanghuanwu decoction compared with the model group (P < 0. 05), and no difference was discovered between sham operation group and nimodipine group (P > 0.05).Conclusions Buyanghuanwu decoction improves the learning and memory abilities in VD rats, the therapeutic mechanism was concerned with lessening the injury of neurons on CA1 field in hippocampus and promoted the expression of NR2B protein and its mRNA.
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AIM:To observe the effect of buyanghuanwu decoction,a Chinese medicine,on the expression of AMPA receptor GluR1 subunit in mRNA and protein levels in rat hippocampus with vascular dementia (VD). METH-ODS:One hundred and forty -four rats were randomly divided into 4 groups:shamoperation group,VD model group,nimodipine group and buyanghuanwu decoction treatment group. The rat model of VD was built up by the method of 4 vessel occlusion. The VD rats were intragastrically treated with buyanghuanwu decoction suspension (pharmacognostic 50 g. kg -1.d -1) and nimodipine suspension (20 mg?kg -1.d-1) for 30 d. The learning and memory abilities were evaluated by Morris water maze testing. The change of GluR1 protein in hippocampal neurons in each group of rats was measured with immunohistochemistry and Western blotting techniques. The expression of GluR1 mRNA in hippocampus was determined by real -time fluorescence quantitative PCR. RESULTS:Compared to sham -operation group,the average escaping latency period (s) of Water maze tests in VD rats prolonged significantly and crossplatform time (numbers/min) shortened distinctly (P 0. 05). Compared to the rats in shamoperation group,the mRNA and protein levels of GluR1 were apparent-ly decreased in VD rats (P 0. 05). CONCLUSION:Buyanghuanwu decoction improves the learning and memory abilities in VD rats. The therapeutic mechanism is associated with lessening the neuron injury on CA1 field in hippocampus and restoring the mRNA and protein ex-pression of GluR1.