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BACKGROUND: The previous experiments have conformed the traditional Chinese medicine (TCM) Jiannaaan, with the effects of tonifying kidney, promoting blood circulation and resolving phlegm, can inhibit the increased content of glucocorticoid (GC) in 2-24 hours after cerebral ischemic reperfusion (CIR), and reduce toxic effects of promoting nervous cell apoptosis induced by high GC. However, it is unclear whether this effect exists in GC receptor (GR).OBJECTIVE: To observe the intervention of TCM Jiannaoan on GR,further study protective mechanism of Jiannaoan power to hippocampal neurons after CIR, and perform positive control with compound almitrine.DESIGN: A randomized and controlled trial taken animals as subjects.SETTING: Center Laboratory of Beijing University of Chinese Medicine.MATERIALS: The experiment was conducted at the Center Laboratory of Beijing University of Traditional Chinese Medicine between July 2002 and March 2003. Eighty male SD rats were randomized into 5 groups with 16 in each: Sham group, model group, treatment group, positive control group and antagonist group. And each group was divided into 4 subgroups: 2, 6,12 and 24 hours after CIR, with 4 rats at every time point.METHODS:①Administration: Except model group, rats in other 4 groups were administrated by intragastric infusion since 7 days before model establishment, once per day, with dose of 7 μL/g per day distilled water in sham group, 7.39 mg/kg per day compound almitrine in positive control group, 6.7 g/kg per day Jiannaoan crude drug (consisted of desertliving cistanche herb, tatarinowii sweetflag rhizome and rhubarb, etc) in treatment group and 10 g/kg per day GR antagonist mifepristone in antagonist group.② After 7-day administration, the CIR models were prepared on the experimental rats with middle cerebral artery occlusion (MCAO) filament method, while the rats in sham group were sutured after common carotid artery detachment at anesthesia, without filament.MAIN OUTCOME MEASURES: All the rats were executed to take out brains at different time points of reperfusion, and the change of GR protein expression was observed with immunohistochemical method then the amount of positive cells were calculated in 3×200 sight of CA2 region.RESULTS: Totally 80 rats were entered into the result analysis. Compared with uninjured side, the protein expression of GR in model group,treatment group, positive control group and antagonist group were significantly lower than that of sham group (P ＜ 0.05), in which GR expression of injured side was equal to that of uninjured side without significant difference. No obvious change was found in the protein expression of GR among treatment group, positive group and antagonist group at different time points of reperfusion, and no significant difference was found between above groups and model group (P ＞ 0.05).CONCLUSION: Jiannaoan power is selective for adjusting GR and content of GC: Jiannaoan can not adjust expression of GR, identical as compound almitrine; But Jiannaoan can protect the neurons through decreasing the content of GC in plasm and brain tissues after CIR.
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Objective: To observe the protective effects of Gastrodine on the cultivated rat brain microvessel endothelial cells damage by mimic cerebral ischemia.Methods: The endothelial cells activity,survival rate,the change in NO content,and the effects of Gastrodine were observed in the cultivated rat brain microvessel endothelial cells(BMEC) damaged by mimic cerebral ischemia.Results: The activity and survival rate of BMEC in the ischemia groups are obviously lower than that in the normal groups;compared with the normal groups,the activity,survival rate and NO content of BMEC in the Gastrodin groups have the increasing tendency;comparing to the ischemia groups,the activity of BMEC in the Gastrodin groups obviously increasing(P
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AIM: To explore the relationship between dynamic changes of population spike (PS) and morphologic alterations in hippocampal CA1 region and morphology after transient ischemia/reperfusion and the improving effects of Chinese herbs 9602. METHODS: Changes of evoking population spike ware investigated by electrical stimulating Schaffer collateral in CA1 region of hippocampal slice after ischemia/reperfusion in vivo . Apoptosis and morphologic alterations at different time points after cerebral ischemia/reperfusion were detected by using TUNEL and Nissl staining. RESULTS: The threshold voltage of CA1 region in evoking population spike increased markedly as compared with sham control. The enhancement of wave amplitude was reduced significantly after tetanic stimulation. The duration of enhancement in amplitude decreased with the passage of reperfusion. Above all were observed from 8 h after ischemia/reperfusion. They became remarkable and got to its top at 7 day after ischemia/reperfusion treatment. TUNEL positive cells were observed in hippocampal CA1 region at 8 h, got to the top at 24 h and then gradually reduced after ischemia/reperfusion. A lot of abnormal cells in CA1 region was found, and the number of pyramidal cell reduced progressively by Nissl staining after ischemia/reperfusion. Chinese herbs 9602 reduced the threshold voltage of CA1 region in evoking population spike remarkably, enhanced the wave amplitude and prolonged the duration of PS enhancement; decreased the number of TUNEL positive cell, prevented the reduction of pyramidal cell in CA1 region. CONCLUSIONS: The excitability and reactivity were decreased and there was a gradual functional disturbance of synaptic transmission in CA1 pyramidal cell and most notable changes happened at 7 d ischemia/reperfusion, suggesting that was partly due to delayed neuronal death induced by ischemia/reperfusion. Apoptosis plays an important role in the functional deficiency of CA1 region of hippocampus induced by cerebral ischemia/reperfusion. The effects of 9602 on ameliorating the excitability and reactivity of CA1 pyramidal cells relate to inhibiting apoptosis, attanuating delayed neuron death induced by ischemia/reperfusion.
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AIM: To investigate the relationship between glucocorticoid (Gc) and injury of hippocampus neurons and the effect of Gc on dementia episode after cerebral ischemia-reperfusion. METHODS: The rat model of middle cerebral artery occlusion (MACO) was established. Cortisol contents in hippocampus and plasma of the model rats were examined by means of the radioimmunoassay at 2 h, 6 h, 12 h, 24 h after reperfusion. RESULTS: The levels of cortisol content in model group were significantly higher than those in sham group and normal group both in hippocampus and plasma. The highest cortisol content was observed at 6 hours after reperfusion. HE staining showed that the impairment of hippocampus neurons was aggravated progressively with reperfusion interval elongating. CONCLUSION: The increased cortisol in hippocampus and plasma, after 2 h cerebral ischemia and 24 h reperfusion, could aggravate the injury of hippocampus neurons and lead to dementia post stroke.
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AIM: To study the nutritional role of the normal conditioned medium of astrocytes (NCMA) on the injured cerebral cortex neurons induced by cerebral hypoxia and reoxygenation in vitro. METHODS: The normal and damaged neurons induced by hypoxia and reoxygenation were cultured with normal conditioned medium of astrocytes (NCMA) after the cerebral cortical astrocytes and neurons of rats were isolated. The viability and survival rate of cultured neurons were investigated by MTT method. RESULTS: NCMA increased the viability and survival rate of cultured neurons. CONCLUSION: NCMA has nutritional and supporting roles on cultured neurons.
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AIM and METHODS: To observe the dynamic changes in relative power of rats brain electrocorticogram(ECoG) and electrohippocampogram(EHG) after ischemia, we studied the changes of rat's ECoG and EHG after ischemia using the method of chronic implanting electrodes in cortex and hippocampus and the effects of Chinese herbs 9602 on them. RESULTS: The frontal ECoG relative power of all bands and total power decreased in 8 hours after ischemia, restored in 24 hours and decreased again after 72 hours. It decreased significantly as compared with that of sham-control 7 day postischemia. The occipital ? band at 72 hour, all bands and total power decreased 7 day after ischemia. As compared with sham-operated control, the ??? and total power of EHG decreased notably at 8, 24 and 72 h after ischemia. The changes were more markedly in 7 day after ischemia. Treated with 9602 and hydergine, the ischemic animals showed significant elevation of ECoG and EHG relative power in comparison with ischemic rats. CONCLUSION: The power of ECoG and EHG decreased after ischemia, it may be correlated with delayed neuronal death induced by ischemia. 9602 prevented the decreases in ECoG and EHG power obviously after ischemia,which probably related to the neuroprotective effects.
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The glomerular synapses of the substantia gelatinosa in the spinal trigeminal nucleus of the rat were examined by electron microscopy. The central axonal ending in the glomcruli forms asymmetrical axodendritic synapses on adjacent type 1 and type 2 dendrites. Type 2 dendritic spines or shafts (dendrites which contain synaptic vesicles) form dendrodendritic synapses on Type 1 dendritic spine or shafts (dendrites without synaptic vesicles) and also form dendroaxonic synapses on the central ending. The peripheral terminals (P) form symmetrical axoaxonic synapses on the central ending and form axodendritic synapses on the dendrites in the glomeruli.