Changes in plasma calcitonin gene-related peptide and serum neuron specific enolase in rats with acute cerebral ischemia after low-frequency electrical stimulation with different waveforms and intensities

Following acute cerebral ischemia in rats, plasma calcitonin gene-related peptide decreased and the level of serum neuron specific enolase and the volume of the infarction increased. Square-wave and triangular-wave electrical stimulation with low or high intensities could increase the plasma calcitonin gene-related peptide, decrease the serum neuron specific enolase and reduce the infarction volume in the brain in rats with cerebral ischemia. There was no significant difference between different wave forms and intensities. The experimental findings indicate that low-frequency electrical stimulation with varying waveforms and intensities can treat acute cerebral ischemia in rats.

Effects of cluster needling of scalp acupuncture on neurofilament protein 200 and signal transducer and activator of transcription 3 in rats with acute cerebral ischemia

Objective:Cluster needling at scalp acupoints has showed satisfying effects with acute cerebral ischemia in clinic whereas the mechanisms are not yet clear completely.This study investigated the influence of cluster needling at scalp acupoints on neurological function,as well as on neurofilament protein 200(NF200)and signal transducer and activator of transcription 3(STAT3)expression,in rats with acute cerebral ischemia.Methods:Fifty-four Sprague-Dawley rats were randomly assigned in equal numbers to the false operation(group F),model(group M),or cluster needling scalp acupuncture(group C)groups.Each group was divided into three subgroups,of six rats each,by acupuncture treatment time(24 h,7 days,and 14 days).The rat local cerebral ischemia model was prepared using a modified suture occlusion method.Group C rats were treated by cluster needling scalp acupuncture,while groups F and M did not receive acupuncture treatment.Neurological effects were evaluated using the Longa score.NF200 and STAT3 expression were measured by western blotting.Results:At 24 h,there were no statistical difference between group C and group M in nerve function(P>.05).On days 7 and 14,nerve function scores in group C were significantly lower than that in group M(respectively were P<.05 and P<.01).In addition,on days 14,expression of NF200 was significantly higher in group C compared with group M(P<.05).Compared with group M,STAT3 expression was also higher in group C on days 7 and 14,although these differences were not statistically significant(both P>.05).Conclusion:Cluster needling scalp acupuncture were efficient in improving nerve function scores in rats with cerebral ischemia,and promoting the recovery of motor function.These improvements were associated with increases in NF200 and STAT3 expression.

Effect of Xingnaojing injection on penumbra transformation in rats with acute cerebral ischemia

Objective:To observe the effect of Xingnaojing injection on penumbra transformation in rats with acute cerebral ischemia.Methods:The rat model of middle cerebral artery occlusion(Middle cerebral artery occlusion,MCAO)was established by suture occlusion.Except the sham operation group,the other groups were randomly divided into model group and Xingnaojing group.The rats in Xingnaojing group were intraperitoneally injected with Xingnaojing injectionaccording to 0.18ml/100g,and the sham operation group and model group were given the same amount of normal saline respectively.24 hours after the establishment of the model,the morphological changes of neurons in the penumbra of the rats were observed by Nissl staining,the ultrastructural changes of neurovascular unit(Neurovascular unit,NVU)were observed by transmission electron microscope(Transmission electron microscope,TEM),and the apoptosis of the ischemic penumbra was detected by in situ apoptosis(TdT-mediated Dutp Nick-End Labeling,TUNEL).Magnetic resonance imaging was used to observe the ischemic evolution of the penumbra of the same rat at 4.5 h and 24 h,respectively.Results:Compared with the sham operation group,the number of neurons in the model group was significantly reduced,the structure of Nissl corpuscles was destroyed,the outline was blurred or disappeared,the pathological morphology of NVU ultrastructure was obviously damaged under transmission electron microscope,a large number of apoptotic cells could be seen in the model group by TUNEL staining(P<0.01),and magnetic resonance imaging showed that there was a large area infarction in the brain tissue of the model group.Compared with the model group,the pathomorphology of neurons and NVU ultrastructure in Xingnaojing group was significantly improved,the number of apoptotic cells was significantly decreased(P<0.01),and the loss rate of penumbra was significantly lower in Xingnaojing group(P<0.05).Conclusion:Xingnaojing injection can improve the state of neurons in ischemic penumbra,reduce the injury of glial cells and microvessels,inhibit apoptosis,promote the transformation of penumbra in rats with acute cerebral ischemia,and save part of penumbra to some extent.it has a certain protective effect on the brain tissue of penumbra in the acute stage of cerebral ischemia.

Brain-Derived Glia Maturation Factor b Participates in Lung Injury Induced by Acute Cerebral Ischemia by Increasing ROS in Endothelial Cells

Brain damage can cause lung injury. To explore the mechanism underlying the lung injury induced by acute cerebral ischemia(ACI), we established a middle cerebral artery occlusion(MCAO) model in male Sprague-Dawley rats. We focused on glia maturation factor b(GMFB) based on quantitative analysis of the global rat serum proteome.Polymerase chain reaction, western blotting, and immunofluorescence revealed that GMFB was overexpressed in astrocytes in the brains of rats subjected to MCAO. We cultured rat primary astrocytes and confirmed that GMFB was also up-regulated in primary astrocytes after oxygen-glucose deprivation(OGD). We subjected the primary astrocytes to Gmfb RNA interference before OGD and collected the conditioned medium(CM) after OGD.We then used the CM to culture pulmonary microvascular endothelial cells(PMVECs) acquired in advance and assessed their status. The viability of the PMVECs improved significantly when Gmfb was blocked. Moreover,ELISA assays revealed an elevation in GMFB concentration in the medium after OGD. Cell cultures containing recombinant GMFB showed increased levels of reactive oxygen species and a deterioration in the state of the cells.In conclusion, GMFB is up-regulated in astrocytes after ACI, and brain-derived GMFB damages PMVECs by increasing reactive oxygen species. GMFB might thus be an initiator of the lung injury induced by ACI.

Effects of Tongmai Huoxue Yin(通脉活血饮) on Tumor Necrosis Factor-alpha in the Acute Cerebral Ischemia Model Rat

Objective:To observe the interfering action of Tongmai Huoxue Yin(通脉活血饮) on the acute cerebral ischemia model rat.Methods:Total 60 SD rats,30 females and 30 males,were randomly divided into 4 groups,sham-operation group,model group,Nimodipine group and Tongmai Huoxue Yin group,15 rats in each group.The acute cerebral ischemia rat model was duplicated,the middle cerebral artery(MCA) were ligated and the thread was inserted for the rats in the model group,Nimodipine group and Tongmai Huoxue Yin group,for the rats in the sham-operation group,the arteries were separated without ligature and the thread was not inserted.After the modeling has succeed,the water-decocted concentrated solution of 20-fold Tongmai Huoxue Yin clinical dosage was intragastrically administrated in a dose of 3 mL /100 g · d divided into twice,1.5 mL /100 g once.Distilled water 3 mL /100 g·d was intragastrically administrated,1.5 mL /100 g once,for the rat in the model group,Nimodipne suspension 3 mL /100 g·d(0.6 mg /100 g) for the Nimodipine group and 3 mL /100 g · d(5.4g /100 g) for the Tongmai Huoxue Yin group,no drugs for the sham-operation group.And changes of tumor necrosis factor-alpha(TNF-α) contents in the serum and brain tissue were investigated.Results:Compared with the model group,compared with the sham-operation group,serum TNF-α content at 5 h of focal cerebral ischemic ischemia in the model group started to increase and reached to the high peak at 12 h,but in both the Tongmai Huoxue Yin group and the Nimodipine group decreased in varying degrees at the same time;compared with the sham-operation group,brain TNF-α content at 6 h of focal cerebral ischemic ischemia in the model group started to increase and reached to the high peak at 12 h,but in both the Tongmai Huoxue Yin group and the Nimodipine group decreased in varying degrees,with the most obviously decreased at 24 h of ischemia.Tongmai Huoxue Yin could significantly decrease TNF-α content in the brain tissue.Conclusion:Tongmai Huoxue Yin has a protective action on acute cerebral ischemia injury in the rat.

An Experimental Proton Magnetic Resonance Spectroscopy Analysis on Early Stage of Acute Focal Cerebral Ischemia

U sing different m odels of focal cerebral ischemia,the temporal and spatial rules of m etabolism and energy changes in the post- ischem ia brain tissue were measured by proton m agnet- ic resonance spectroscopy(1 HMRS) to provide valuable inform ation for judging the prognosis of a- cute focal cerebral ischemia and carrying out effective therapy.Nine healthy Sprague- Dawly rats (both sexes) were randomly divided into two groups:The rats in the group A(n=4 ) were occlud- ed with self- thrombus for1h;The rats in the group B(n=5 ) were occluded with thread- em boli for1h.The 1 H MRS at30 ,4 0 ,5 0 ,6 0 min respectively was examined and the m etabolic changes of NAA,Cho and L ac in the regions of interest were sem iquantitatively analyzed. The spectrum intregral calculus area ratio of NAA,Cho,L ac to Pcr+Cr was setas the criterion.The values of NAA· Cho in the regions of interest were declined gradually within 1h after ischem ia, especially,the ratio of Cho/ (Pcr+Cr) ,NAA/ (Pcr+Cr) at6 0 m in had significant difference with that at5 0 min(P<0 .0 5 ) .The ratio of L ac/ (Pcr+Cr) began to decrease at4 0 min from initial in- crease of L ac in both A and B groups.MR proton spectrum analysis was a non- invasive,directand com prehensive tool for the study of cellular metabolism and the status of the biochemical energy in acute ischem ia stroke.

Protective effects of Radix Cynanchum bungei on ischemia-induced neuronal and cognitive impairment in mice

OBJECTIVE To investigate the effects of Radix Cynanchum bungei extract(RCBE) on cerebral ischemia-reperfusion(I/R) and acute cerebral ischemia induced impairment in mice.METHODS I/R model was induced by bilateral carotid artery occlusion(BCAO)-reperfusion method and Y-maze learning and memory performance was assessed after reperfusion. Na^+-K^+-ATPase,Ca^(2+)-ATPase and SOD activity,as well as MDA content in mouse brain tissue were measured. Numbers of mouth-opening breaths of the isolated mouse head were observed in acute cerebral ischemia mice.RESULTS Learning and memory ability in mice with RCBE were improved significantly compared with model group. The activity of SOD,Na^+-K^+-ATPase and Ca^(2+)-ATPase were increased,while MDA contents decreased after RCBE(0.5,1.0 and 2.0 g·kg^(-1)) and piracetam(0.5 g·kg^(-1)) treatment compared with the model group. RCBE at all concentrations significantly prolonged the number of mouth-opening breaths of the isolated mouse head. CONCLUSION RCBE preconditioning exerts a marked neuroprotective effect on the ischemia brain,which is related to improve the learning and memory via regulating energy metabolism and anti-oxidation.

Limb remote ischemic postconditioning protects integrity of the blood-brain barrier after stroke

Integrity of the blood-brain barrier structure is essential for maintaining the internal environment of the brain.Development of cerebral infarction and brain edema is strongly associated with blood-brain barrier leakage.Therefore,studies have suggested that protecting the blood-brain barrier may be an effective method for treating acute stroke.To examine this possibility,stroke model rats were established by middle cerebral artery occlusion and reperfusion.Remote ischemic postconditioning was immediately induced by three cycles of 10-minute ischemia/10-minute reperfusion of bilateral hind limbs at the beginning of middle cerebral artery occlusion reperfusion.Neurological function of rat models was evaluated using Zea Longa’s method.Permeability of the blood-brain barrier was assessed by Evans blue leakage.Infarct volume and brain edema were evaluated using 2,3,5-triphenyltetrazolium chloride staining.Expression of matrix metalloproteinase-9 and claudin-5 m RNA was determined by real-time quantitative reverse transcription-polymerase chain reaction.Expression of matrix metalloproteinase-9 and claudin-5 protein was measured by western blot assay.The number of matrix metalloproteinase-9-and claudin-5-positive cells was analyzed using immunohistochemistry.Our results showed that remote ischemic postconditioning alleviated disruption of the blood-brain barrier,reduced infarct volume and edema,decreased expression of matrix metalloproteinase-9 m RNA and protein and the number of positive cells,increased expression of claudin-5 m RNA and protein and the number of positive cells,and remarkably improved neurological function.These findings confirm that by suppressing expression of matrix metalloproteinase-9 and claudin-5 induced by acute ischemia/reperfusion,remote ischemic postconditioning reduces blood-brain barrier injury,mitigates ischemic injury,and exerts protective effects on the brain.

Effects of polygonatum sibiricum polysaccharide on learning and memory in a scopolamine-induced mouse model of dementia

BACKGROUND： Learning and memory processes are accompanied by complex neuropathological and biochemical changes. Free radicals play an important role in learning and memory damage. OBJECTIVE： To observe the effects of polygonatum sibiricum polysaccharide （PSP） in comparison with vitamin 12 on inhibiting free radical damage, as well as improving the degree of cerebral ischemia and learning and memory in a scopolamine-induced mouse model of dementia. DESIGN： Randomized controlled animal study. SETTINGS： Department of Pharmacology, Taishan Medical College; Shandong Jewim Pharmaceutical Co., Ltd. MATERIALS： A total of 105 healthy Kunming mice, comprising 90 males and 15 females that were clean grade, were provided by the Animal Center of Taishan Medical College. PSP （extracted and purified by Huangjing, Taishan） was provided by the Department of Traditional Chinese Medicine, Taishan Medical College （purity of 79.6% by using a phenol-concentrated sulphate acid method）, and hydrogen bromine acid scopolamine injection solution （SCO） by Shanghai Hefeng Pharmaceutical Co., Ltd. METHODS： This study was performed at the Pharmacological Laboratory of Taishan Medical College from March to June 2007. （1） A total of 75 healthy Kunming male mice of clean grade were randomly divided into a normal control group, positive control group, and low-dosage and high-dosage PSP groups, with 15 mice in each group. Mice in both the low-dosage and high-dosage PSP groups were intragastrically administered 0.5 g/kg and 2.0 g/kg PSP, respectively. Mice in the positive control group were intragastrically administered 0.5 g/kg vitamin 12. In addition, mice in both the normal control group and model group were intragastrically administered the same volume of saline, respectively, once a day for 7 consecutive days. One hour after the final administration on day 6, mice in the positive control group, model group, low-dosage and high-dosage PSP groups were subcutaneously injected with 3.0 mg/kg SCO, while mice in the normal control group were subcutaneously injected with the same volume of distilled water. Ten minutes later, the step test was employed to measure memory. The training was performed 5 times, with 30-minute intervals between 2 sets. If the mice remained on the platform （latent period） for 30 minutes, they were determined to have learned the task. An eligible percentage was then recorded. Twenty-four hours later, the number of error responses from each mouse was recorded in a 5-minute period, based on the above-mentioned parameters. Mice were sacrificed under anesthesia. The activities of glutathione hyperoxide enzyme （GSH-Px）, superoxide dismutase （SOD）, and the content of malondialdehyde （MDA） were assayed using an UV spectrophotometer. （2） The remaining 30 healthy Kunming mice of both genders were randomly divided into 3 groups, including control group, low-dosage PSP group, and high-dosage PSP group, with 10 mice in each group. Mice in both the low-dosage and high-dosage PSP groups were intragastrically administered 0.5 g/kg and 2.0 g/kg PSP, respectively, while the mice in the control group were perfused with the same volume of saline. Forty minutes later, the mice under superficial anesthesia were decapitated, and the number and duration of mouth-opening breaths of the isolated mouse head were immediately recorded. MAIN OUTCOME MEASURE： （1） Numbers of error responses within 5 minutes on the platform. （2） GSH-Px and SOD activity, as well as MDA content in mouse brain tissue. （3） Numbers and duration of mouth-opening breaths of the isolated mouse head. RESULTS： Of the 105 Kunming experimental mice, two mice died due to electric shock during the step-down test, therefore, a total of 103 mice were involved in the final analysis. （1） Effects of PSP on learning in mice： The eligible percentage in the high-dosage PSP group was higher than the control group at the 3rd and 5th training sessions （P 〈 0.05）. （2） Effects of PSP on memory in mice： The number of errors in the step-down test in the model group was higher than in the normal control group （P 〈 0.01）. Compared to the model group, the number of errors in the step-down test was lower in both the low-dosage and high-dosage PSP groups （P 〈 0.01）. （3） Effects of PSP on amount of GSH-Px, SOD, and MDA in mouse brain tissue： SOD and GSH-Px activity was higher in both the low-dosage and high-dosage PSP groups than in the model group. MDA content was lower in the high-dosage PSP group, compared to the model group. GSH-Px activity in the brain tissue of the high-dosage PSP group was similar to the positive control group （P 〉 0.05）. （4） Effects of PSP on acute cerebral ischemia in mice： The low-dosage PSP, and in particular the high-dosage PSP, prolonged the number and duration of mouth-opening breaths of the isolated mouse head （P 〈 0.05, 0.01）. CONCLUSION： PSP can improve learning and memory in a scopolamine-induced mouse model of dementia by reducing the damaging effects of cerebral ischemia and anti-oxidation. In addition, the effects are dose-dependent and are similar to those provided by vitamin E.