orrelation of aquaporin-4 expression to blood-brain barrier permeability in rats with focal cerebral ischemia**★

BACKGROUND： Ischemic cerebrovascular disease causes injury to the blood-brain barrier. The occurrence of brain edema is associated with aquaporin expression following cerebral ischemia/reperfusion. OBJECTIVE： To analyze the correlation of aquaporin-4 expression to brain edema and blood-brain barrier permeability in brain tissues of rat models of ischemia/reperfusion. DESIGN, TIME AND SETTING： The randomized control experiment was performed at the Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical College, China from December 2006 to October 2007. MATERIALS： A total of 112 adult, male, Sprague-Dawley rats, weighing 220-250 g, were used to establish rat models of middle cerebral artery occlusion and reperfusion by the suture method. Rabbit anti-aquaporin-4 （Santa Cruz, USA） and Evans blue （Sigma, USA） were used to analyze the tissue. METHODS： The rats were randomized into sham-operated （n = 16） and ischemia/reperfusion （n = 96） groups. There were 6 time points in the ischemia/reperfusion group, comprising 4, 6, 12, 24, 48, and 72 hours after reperfusion, with 16 rats for each time point. Rat models in the sham-operated group at 4 hours after surgery and rat models in the ischemia/reperfusion group at different time points were equally and randomly assigned into 4 different subgroups. MAIN OUTCOME MEASURES： Brain water content on the ischemic side and the control side was measured using the dry-wet weight method. Blood-brain barrier function was determined by Evans Blue. Aquaporin-4 expression surrounding the ischemic focus, as well as the correlation of aquaporin-4 expression with brain water content and Evans blue staining, were measured using immunohistochemistry and Western blot analysis. RESULTS： Brain water content on the ischemic side significantly increased at 12 hours after reperfusion, reached a peak at 48 hours, and was still high at 72 hours. Brain water content was greater on the ischemic hemispheres, compared with the control hemispheres at 6, 12, 24, 48, an     

Brain edema and tumor necrosis factor-like weak inducer of apoptosis in rats with cerebral ischemia

BACKGROUND： Recent studies have demonstrated that tumor necrosis factor-like weak inducer of apoptosis （TWEAK） participates in brain edema. However, it is unclear whether blood-brain barrier （BBB） disruption is associated with TWEAK during the process of brain edema OBJECTIVE： To investigate the effects of TWEAK on BBB permeability in brain edema. DESIGN, TIME AND SETTING： An immunohistochemical observation, randomized, controlled animal experiment was performed at the Laboratory of Neurosurgical Anatomy, Xiangya Medical College, Central South University ＆ Central Laboratory, Third Xiangya Hospital, Central South University between January 2006 and December 2007. MATERIALS： A total of 48 adult Wistar rats were randomly divided into three groups： normal control （n = 8）, sham-operated （n = 8）, and ischemia/reperfusion （n = 32）. Rats from the ischemia/reperfusion group were randomly assigned to four subgroups according to different time points, i.e., 2 hours of ischemia followed by 6 hours （n = 8）, 12 hours （n = 8）, 1 day （n = 8）, or 12 days （n = 8） of reperfusion. METHODS： Focal cerebral ischemia/reperfusion injury was induced by middle cerebral artery occlusion （MCAO） using the suture method in rats from the ischemia/reperfusion group. Thread was introduced at a depth of 17-19 mm. Rats in the sham-operated group were subjected to experimental procedures similar to the ischemia/reperfusion group; however, the introducing depth of thread was 10 mm. The normal control group was not given any intervention. MAIN OUTCOME MEASURES： TWEAK expression was examined by immunohistochemistry; brain water content on the ischemic side was calculated as the ratio of dry to wet tissue weight; BBB permeability was measured by Evans blue extravasation. RESULTS： A total of eight rats died prior to and after surgery and an additional eight rats were randomly entered into the study. Thus 48 rats were included in the final analysis. In the ischemia/reperfusion group, TWEAK-positiv     

Matrix metalloproteinase-9 expression and blood brain barrier permeability in the rat brain after cerebral ischemia/reperfusion injury**☆

BACKGROUND： The integrity of the blood brain barrier （BBB） plays an important role in the patho-physiological process of cerebral ischemia/reperfusion injury. It has been recently observed that metalloproteinase-9 （MMP-9） is closely related to cerebral ischemia/reperfusion injury OBJECTIVE： This study was designed to observe MMP-9 expression in the rat brain after cerebral ischemia/reperfusion injury and to investigate its correlation to BBB permeability. DESIGN, TIME AND SETTING： This study, a randomized controlled animal experiment, was performed at the Institute of Neurobiology, Central South University between September 2005 and March 2006. MATERIALS： Ninety healthy male SD rats, aged 3-4 months, weighing 200-280 g, were used in the present study. Rabbit anti-rat MMP-9 polyclonal antibody （Boster, Wuhan, China） and Evans blue （Sigma, USA） were also used. METHODS： All rats were randomly divided into 9 groups with 10 rats in each group： normal control group, sham-operated group, and ischemia for 2 hours followed by reperfusion for 3, 6, 12 hours, 1, 2, 4 and 7 days groups. In the ischemia/reperfusion groups, rats were subjected to ischemia/reperfusion injury by suture occlusion of the right middle cerebral artery. In the sham-operated group, rats were merely subjected to vessel dissociation. In the normal control group, rats were not modeled. MAIN OUTCOME MEASURES： BBB permeability was assessed by determining the level of effusion of Evans blue. MMP-9 expression was detected by an immunohistochemical method. RESULTS： All 90 rats were included in the final analysis. BBB permeability alteration was closely correlated to ischemia/reperfusion time. BBB permeability began to increase at ischemia/reperfusion for 3 hours, then it gradually reached a peak level at ischemia/reperfusion for 1 day, and thereafter it gradually decreased. MMP-9 expression began to increase at ischemia/reperfusion for 3 hours, then gradually reached its peak level 2 days after perfusion, and thereafter it grad     

Cervical sympathetic trunk transection affects inducible nitric oxide synthase expression in rat hippocampus following focal cerebral ischemia/reperfusion injury

BACKGROUND： The stellate ganglion block （SGB） plays a protective role in focal cerebral ischemia/reperfusion injury. The human SGB can be simulated by transection of the cervical sympathetic trunk （TCST） in rats. OBJECTIVE： To observe the effects of TCST on inducible nitric oxide synthase （iNOS） levels and cerebral infarct volume in the hippocampus of rats with cerebral ischemia/reperfusion injury, and to analyze the mechanism of action. DESIGN, TIME AND SETTING： A completely randomized, controlled, neuropathological experiment was performed at the Institute of Neurological Disease, Taihe Hospital, Yunyang Medical College between March and September 2006. MATERIALS： A total of 93 Wistar rats, aged 1718 weeks, of either gender, were used for this study. 2, 3, 5-triphenyl tetrazolium chloride was purchased from Changsha Hongyuan Biological Reagent Company China. Rabbit iNOS antibody and goat anti-rabbit IgG antibody were the products of Wuhan Boster Biological Reagent Co., Ltd., China. METHODS： Ten rats were randomly selected for the sham-operated group. Cerebral ischemia/reperfusion injury was induced by middle cerebral artery occlusion （MCAO） using the suture method in the remaining rats. Forty successful rat models were randomly and equally divided into the following two groups： （1） TCST group： subsequent to TCST, MCAO was performed for 2 hours, followed by 24 hours reperfusion; （2） model group： rats underwent experimental procedures similar to the TCST group, with the exception of TCST. Rats in the sham-operated group were subjected to experimental procedures similar to the model group; however, the thread was only introduced to a depth of 10 mm. MAIN OUTCOME MEASURES： Following 24 hours of reperfusion, functional neurological deficits were scored. Brain tissue sections from ten rats of each group were used to measure cerebral infarct volume by TTC staining. Hippocampal tissue sections of an additional ten rats from each group were used to detect iNOS levels using the s     

Protective effects and time course of Huangqi on early-stage free radical injury following brain trauma in rats★

BACKGROUND： Huangqi （Astragalus mongholicus）, a Chinese herb, has already been included in the ＂Chinese Pharmacopoeia＂ for the treatment of ischemic cerebrovascular disease. Secondary injury following brain injury is associated with free radical production, and Huangqi possesses the ability to ameliorate free radical-mediated injury. OBJECTIVE： This study was designed to observe the correlation between anti-free-radical properties of Huangqi and early histological changes of brain tissues following traumatic brain injury. DESIGN, TIME AND SETTING： This study, a randomized, controlled, animal experiment, was performed from May 2006 to June 2007 at the Experimental Center of Science and Technology, School of Basic Science, Liaoning Medical University, Jinzhou City, Liaoning Province, China. MATERIALS： Healthy, adult, Sprague Dawley rats of either gender were included. Huangqi injection was purchased from Heilongjiang Provincial Zhenbaodao Pharmaceutical Co., Ltd., China （National License Medical Number： Z23020781）. Na^＋-K^＋-adenosine triphosphatase （ATPase）, Ca^2＋-ATPase, and Mg^2＋-ATPase, as well as kits to measure superoxide dismutase （SOD） activity and malondialdehyde （MDA） content, were purchased from Nanjing Jiancheng Biological Reagent Company, China. METHODS： Seventy-two rats were randomly divided into three groups, with 24 rats in each group： （1） sham-operated group： rats were only exposed, but not injured; （2） model group： brain focal laceration rat models were established by free-falling. These groups were intraperitoneally injected with saline, once every 10 hours; （3） Huangqi group： rats were intraperitoneally injected with 4 mL/kg Huangqi （2 g/mL）, once every 10 hours, following brain focal laceration by free-falling. MAIN OUTCOME MEASURES： Ultrastructural changes in brain tissue were observed under an electron microscope 24 hours after injury. The water content of brain tissue was measured using the dry-wet weight method. In additio     

High frequency electrical field-ultrashort wave therapy for treatment of cerebral ischemia/reperfusion injury in rats☆ Histopathological evaluation

BACKGROUND: Ultrashortwave (USW) therapy may be a new method for treatment of ischemic cerebrovascular diseases. It is necessary to study its treatment time window. OBJECTIVE: To observe the effect of USW on reperfusion injury after occlusion of the middle cerebral artery (MCAO) in rats and discuss its acting mechanisms and best occasion. DESIGN: Randomized controlled observation, animal experiment. SETTING: Laboratory of Department of Rehabilitation Medicine, First Hospital Affiliated to China Medical University. MATERIALS: Sixty-six healthy Wistar rats of either gender and of clean grade, aged 18–20 weeks, weighing from 250 to 300 g, were provided by the Experimental Animal Center of China Medical University. An USW device (Shanghai Electrical Device Company) with the frequency of 40.68 MHz and the maximum output power of 40 W, and the first channel power controlled at about 11 W was used in this study. Output power was determined by photometry. METHODS: Sixty-six rats were randomly divided into 3 groups: Sham-operation group (n =6): The suture was inserted only 1.0 depth during operation, which did not cause MACO; Model group (n =12): The USW treatment procedure was performed with the power off on the model rats; USW treatment group (n =48): The 48 rats were randomly divided into modeling 0, 6, 12 and 18 hours 4 subgroups. USW therapy without heat was used on the head of rats for 10 minutes at each time point. Twelve rats in USW treatment group were decapitated following treatment at each time point, and then their brain tissues were harvested. The rat brain tissues in other groups were harvested by decapitation at 24 hours after modeling. When the rats were awake, the neurologic deficit was scored by Zea-Longa five-point scale (a score of 0 indicated no neurologic deficit, a score of 1 indicated failure to extend left paw fully, a score of 2 indicated circling to the left, and a score of 3 indicated falling to the left, and rats with a score of 4 did not walk spontaneously and has a depressed level of consciousness.) Rats which still survived at 24 hours and was scored 1 and 2 on the neurologic scoring were involved in the analysis. ① Determination of cerebral water content: Cerebral water contents of healthy and injured hemisphere were determined by wet/dry weighing method. Cerebral water content (100%) =(1–dry/wet weight)×100%.②Infarction volume: The brain tissue was sliced into 2 mm sections and each section was stained with 20 g/L 2,3,5-triphenyltetrazolium chloride (TTC) by TTC staining technique for 30 minutes in a water bath at 37 ℃.Then, the section was fixed in 100 g/L formaldehyde for 10 minutes .The infarction volume was analyzed by using an imaging analyzer.③ Preparation of light microscopic sample: The rat brain tissue fixed by 100 g/L neutral formaldehyde and stained with TTC, were gradiently dehydrated with alcoholic, embedded with paraffin, sliced and stained by HE, finally, the sections were observed under the light microscope. MAIN OUTCOME MEASURES: Cerebral water content, cerebral infarction volume and cerebral histomorphology of rats in each group. RESULTS: Sixty-six rats were involved in the final analysis. ①Cerebral water content: There were no significant differences of cerebral water content in healthy hemisphere among groups (P > 0.05). Cerebral water content of injured hemisphere in the model group and at modeling 0, 6, 12 and 18 hours in the USW treatment group was (81.50±0.74) %, (81.02±0.83) %, (79.78±0.70) %, (79.74±0.84) %, (79.39±1.06) %, respectively, which was significantly higher than that in the sham-operation group [(78.09±0.52) %, P < 0.05]. At modeling 0, 6 and 12 hours, the cerebral water content in the injured hemisphere in the USW treatment group was significantly lower than that in the model group, respectively (P < 0.05). It indicated that USW treatment given at 6, 12 and 18 hours after ischemia/reperfusion can lessen brain edema. ② Cerebral infarction volume: At modeling 18 hours, cerebral infarction volume in the injured hemisphere of USW treatment group was smaller than that in the model group [（191.62±121.45），（362.03±142.01）mm3，t =2.23，P < 0.05]. ③ Cerebral histomorphological observation: No swelling was found in the brain tissue section of rats in the sham-operation group. In the model group, the size of infarction hemisphere was obviously increased, gyrus became flattened, cortical sulci was shallow, the color at infarct focus obviously became light, and the tissue was fragile and brittle. In the sham-operation group, it was found under the microscope that mesenchyma was highly swelled, neuronal peripheral interspace was obviously broadened, neurons presented triangle, nucleoli were reduced, condensed even disappeared, and neutrophils in the vascular cavity were obviously increased. In the USW treatment group, pathological injury was not obviously lessened at 0 hour, moderate or mild edema could be found in the injured hemisphere of USW treatment group at modeling 6,12 and 18 hours, and at this time, neutrophils in vascular cavity were increased slightly, and pathological injuries were lessened. CONCLUSION: USW may play a protective effect on cerebral ischemia/reperfusion injury by decreasing brain edema and/or cerebral infarction volume. The treatment action of USW may start at 6 hours after reperfusion, and the best occasion of application may be at 18 hours after reperfusion.     

Changes in neuronal apoptosis and apoptosis modulatory factors in cerebral ischemia/reperfusion

BACKGROUND: The high concentration of glutamate release is the main cause for neuronal cell death. The relationship between glutamate level and apoptosis during ischemia/reperfusion injury is still unclear. OBJECTIVE: To observe the neuronal apoptosis at 24 and 72 hours following cerebral ischemia/reperfusion in rats, and analyze the possible influencing factors. DESIGN: A randomized controlled animal experiment. SETTING: School of Medicine, Southern Yangtze University. MATERIALS: Totally 30 male adult Sprague Dawley (SD) rats of clean grade, weighing 240–290 g, were obtained from Shanghai Experimental Animal Center, Chinese Academy of Sciences. The rats were randomly divided into sham-operated group (n=10) and model group (n=20). Each group was observed at 24 and 72 hours after ischemia/reperfusion, 5 rats at each time point in the sham-operated group, whereas 12 at 24 hours and 8 at 72 hours in the model group. Kits for determining apoptosis and Bcl-2 were bought from Wuhan Boster Biological Technology, Co., Ltd.; Kit for calcineurin from Nanjing Jiancheng Bioengineering Institute. METHODS: The experiment was carried out in the Functional Scientific Research Room of Southern Yangtze University from June to October in 2006. ① Right middle cerebral artery was occluded by inserting a thread through internal carotid artery (ICA). The surgical process for the sham-operated rats was the same as that in the model group except a nylon suture inserted the ICA. According to Longa five-degree standard, the neurological deficit evaluation of rats was evaluated after surgery, and grades 1–3 were taken as successful model establishment. The blood was recirculated by withdrawing the nylon filament under anesthesia at 2 hours after ischemia in successful rat models. ②After reperfusion, the brain tissue was quickly removed at 24 or 72 hours and the slices were obtained from optic chiasma to funnel manubrium. The changes of the number of apoptotic cells were observed using the terminal deoxynucleotidyl transferase mediated dUTP-biotin nick-end labeling method. The expressions of Bcl-2 protein were determined with immunohistochemical staining. The activity of calcineurin was determined by the inorganic phosphorus method. The content of excitatory amino acid was detected by high performance liquid chromatography. MAIN OUTCOME MEASURES: ① Glutanate content in brain tissue; ② Conditions of apoptosis; ③ Calcineurin activity in brain tissue; ④ Bcl-2 expression in brain tissue. RESULTS: Totally 30 SD rats were used, 5 died and the other 25 were involved in the analysis of results. ① Changes of apoptosis: There were 0–3 apoptotic cells in the sham-operated group. In the model group, the numbers of apoptotic cells were obviously increased at 24 and 72 hours of reperfusion (P < 0.01), and it was markedly reduced at 72 hours as compared with 24 hours (P < 0.01). ② Changes of glutanate content: The glutamate contents at 24 and 72 hours of reperfusion in the model group were obviously higher than those in the sham-operated group (P < 0.01); In the model group, it was obviously increased at 24 hours as compared with 72 hours (P < 0.01). ③ Changes of Bcl-2 protein: In the model group, the Bcl-2 protein expression had no obvious changes at 24 hours of reperfusion, and it was obviously enhanced at 72 hours, which was obviously different from that in the sham-operated group and that at 24 hours (P < 0.01). ④ Changes of calcinerin activity: In the model group, the activity of calcineurin in brain tissue had no obvious changes at 24 hours of reperfusion; The activity of calcineurin at 72 hours was obviously higher than that in the sham-operated group and that at 24 hours (P < 0.01). CONCLUSION: The brain cyto-apoptosis action at different time points following reperfusion incompletely depends on the glutamate levels, while it depends on the interaction of some apoptosis related factors, such as amino acid, calcineurin, and Bcl-2, etc.     

Naoxintong dose effects on inflammatory factor expression in the rat brain following focal cerebral ischemia

BACKGROUND： Certain components of tetramethylpyrazine, a traditional Chinese medicine, exhibit protective effects against brain injury. OBJECTIVE： To investigate the effects of different Naoxintong doses on expression of nuclear factor-kappa B （ kB）, interleukin-6, tumor necrosis factor-α, and complement 3 in rats following focal cerebral ischemia. DESIGN, TIME AND SETTING： The randomized experiment was performed at the Laboratory of Neurology, Second Hospital of Hebei Medical University from June 2004 to June 2006. MATERIALS： A total of 150 adult, healthy, male, Sprague Dawley rats, weighing 280-320g, were selected. Naoxintong powder （mainly comprising szechwan lovage rhizome, milkvetch root, danshen root, and radix angelicae sinensis） was obtained from Buchang Pharmacy Co., Ltd. in Xianyang City of Shanxi Province of China, lot number 040608. METHODS： The rats were randomly assigned into sham operation, saline, high-dose Naoxintong, moderate-dose Naoxintong, and low-dose Naoxintong groups, with 30 rats in each group. Rat models of middle cerebral artery occlusion were established using the suture method, with the exception of the sham operation group. Rats in the high-dose, moderate-dose and low-dose Naoxintong groups received 4, 2, and 1 g/kg Naoxintong respectively, by gavage. Rats in the saline group were treated with 1 mL saline by gavage All rats were administered by gavage at 5 and 23 hours following surgery, and subsequently, once per day. MAIN OUTCOME MEASURES： At 6, 24, 48, 72 hours, and 7 days following model establishment, brain water content was measured. Histopathological changes in brain tissues were detected using hematoxylin-eosin staining. Expression of nuclear factor- kB, interleukin-6, tumor necrosis factor- α, and complement 3 was examined by immunohistochemistry. RESULTS： A total of 150 rats were included in the final analysis with no loss. Brain water content was significantly increased in the ischemic hemisphere of rats from the saline, as well as the high-dose, mo     

Effects of transection of cervical sympathetic trunk on cerebral infarct volume and oxygen free radical levels in rats with focal cerebral ischemia/reperfusion injury*★

BACKGROUND： Stellate ganglion block （SGB） plays a protective role on the brain, but the precise mechanism of action is not clear. OBJECTIVE： To simulate SGB by transection of the cervical sympathetic trunk （TCST） and to investigate the TCST effects on changes in cerebral infarct volume and oxygen free radical levels in rats with focal cerebral ischemia/reperfusion injury. DESIGN, TIME AND SETTING： A complete randomized control animal experiment was performed at the Institute of Neurological Diseases of Taihe Hospital, Yunyang Medical College from February to December 2005. MATERIALS： A total of 101 healthy Wistar rats, weighing 280-320 g, of both genders, aged 17-18 weeks, were used in this study. 2, 3, 5-triphenyltetrazolium chloride （TTC） was purchased from Changsha Hongyuan Biological Company. Superoxide dismutase （SOD）, malondialdehyde （MDA） and nitric oxide （NO） assay kits were provided by Nanjing Jiancheng Bioengineering Institute. METHODS： Rats were randomly divided into a TCST group, a model group and a sham operation group. Successful models were included in the final analysis, with at least 20 rats in each group. After TCST, rat models of focal cerebral ischemia/reperfusion injury were established in the TCST group by receiving middle cerebral artery occlusion （MCAO） by the intraluminal suture method for 2 hours, followed by 24 hours of reperfusion. Rat models of focal cerebral ischemia/reperfusion injury were made in the model group. Rats in the sham operation group underwent experimental procedures as for the model group, threading depth of 10 mm, and middle cerebral artery was not ligated. MAIN OUTCOME MEASURES： Brain tissue sections of ten rats from each group were used to measure cerebral infarct volume by TTC staining. Brain tissue homogenate of another ten rats from each group was used to detect SOD activities, MDA contents and NO levels. Rat neurological function was assessed by neurobehavioral measures. RESULTS： Cerebral infarct volume was bigger in the     

Influence of Ganoderma lucidum spores on the levels of neuropeptide Y and somatostatin in brains of seizure rats*★

BACKGROUND： Previous research has revealed that somatostatin can induce epilepsy, and that the levels of neuropeptide Y may increase and become more active in brain areas with epileptic seizures. OBJECTIVE： To observe the effect of Ganoderma luciclum spore powder on the neuropeptide Y and somatostatin content in the cerebral cortex and hippocampal regions of seizure rats induced by pentylenetetrazol （PTZ）. Furthermore, to verify any effect of Ganoderma lucidum spore powder on inhibition of epileptic seizures. DESIGN, TIME AND SETTING： A randomized group animal study was performed in August 2007 in the School of Basic Medical Sciences, Jiamusi University （Jiamusi, Heilongjiang, China）. MATERIALS： Thirty healthy, male, Wistar rats, aged 12 weeks and weighing 180-220 g, were taken as the experimental animals. PTZ （Sigma Company, United States） was used to induce epilepsy. Ganoderma lucidum spores （Leyss, ex Fr variety） were purchased from Jiamusi City Wild Growing Case of the Ganoderma Lucidum （China）. Rabbit anti-somatostatin antibodies and secondary antibodies were purchased from Wuhan Boster Company （China）. Neuropeptide Y radioimmunoassay kit was purchased from Beijing Furui Biotechnology Company （China）. METHODS： Thirty rats were randomly divided into three groups： a control group, an epilepsy model group and a Ganoderma lucidum spore-treated group. Each group contained 10 animals. Rats in the epilepsy model group were treated with intraperitoneal injections of PTZ and gastric perfusion of physiologic saline. In the Ganoderma lucidum spore-treated group, intraperitoneal injection of PTZ and gastric perfusion of Ganoderma lucidum spore powder were administered. The blank control group was only administered with the physiological saline by intraperitoneal injection and gastric perfusion. MAIN OUTCOME MEASURES： Immunohistochemical staining and radioimmunoassay methods were used to observe the changes of somatostatin and neuropeptide Y content in brain tissue of epileptic r     

蛛网膜下腔出血后血脑屏障通透性的实验研究

目的观察蛛网膜下腔出血后脑血管痉挛后血管通透性改变以及探讨其发生机制。方法将36只新西兰大白兔随机平分为6组,各手术组通过枕大池注血建立兔蛛网膜下腔出血后脑血管痉挛的模型,假手术组枕大池注入生理盐水。假手术1组和手术1组用于通过免疫组化方法检测血管内皮细胞的caspase-3表达情况,作为细胞凋亡的标志;假手术2组和手术2组用于检测注血后3d处死动物,比较手术组与对照组脑含水量。假手术3组和手术3组用于通过Evan's蓝荧光染色方法检测手术组和非手术组血脑屏障的通透性。结果手术1组的基底血管内皮细胞caspase-3高度表达,与假手术1组相比有显著统计学差异,反映了蛛网膜下腔出血后基底血管内皮细胞发生了细胞凋亡;手术2组与假手术2组脑含水量相比增加,有显著统计学差异;手术3组脑组织Evan,s蓝含量明显增加,与假手术3组相比有显著统计学差异,反映了蛛网膜下腔出血后血脑屏障的通透性也发生了明显改变。结论血管内皮细胞凋亡可能是蛛网膜下腔出血后脑血管痉挛引发血脑屏障损伤的重要原因。     

Nimodipine Attenuation of Early Brain Dysfunctions Is Partially Related to its Inverting Acute Vasospasm in a Cisterna Magna Subarachnoid Hemorrhage (SAH) Model in Rats

ABSTRACT Subarachnoid hemorrhage (SAH)-induced brain injury is highly related to neurological deficits and mortality. Regional cerebral blood flow (rCBF) changes and vasoconstriction are two complications that occur soon after SAH experimentally. In this study we investigated the changes in rCBF and vertebro-basilar arterial diameter in a cisterna megna SAH model in Sprague-Dawley rats and intended to explore whether improving early rCBF reduction and cerebral vasospasm could contribute to alleviating blood-brain barrier (BBB) dysfunction. In rats for rCBF, vasospasm and BBB permeability assessments, nimodipine (NDP) or saline was administered intravenously 5 minutes after SAH. rCBF within the first 60 minutes after SAH was measured by laser Doppler flowmetry. BBB permeability indexed by Evans Blue extravasation was assessed 4?hours after SAH. Angiography for the caliber changes of the vertebro-basilar artery were conducted 30 minutes post SAH. Pronounced rCBF reduction and vasospasm were observed soon after SAH, followed by BBB permeability increment. NDP administration could improve rCBF and attenuate vasospasm, followed by the alleviation of BBB permeability. Our results demonstrate that early improvement of cerebral circulation by NDP may contribute to the reduction in brain injury indexed by BBB disruption.     

Correlation of aquaporin-4 expression to blood-brain barrier permeability in rats with focal cerebral ischemia

BACKGROUND: Ischemic cerebrovascular disease causes injury to the blood-brain barrier. The occurrence of brain edema is associated with aquaporin expression following cerebral ischemia/reperfusion. OBJECTIVE: To analyze the correlation of aquaporin-4 expression to brain edema and blood-brain barrier permeability in brain tissues of rat models of ischemia/reperfusion. DESIGN, TIME AND SETTING: The randomized control experiment was performed at the Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical College, China from December 2006 to October 2007. MATERIALS: A total of 112 adult, male, Sprague-Dawley rats, weighing 220-250 g, were used to establish rat models of middle cerebral artery occlusion and reperfusion by the suture method. Rabbit anti-aquaporin-4 (Santa Cruz, USA) and Evans blue (Sigma, USA) were used to analyze the tissue. METHODS: The rats were randomized into sham-operated (n = 16) and ischemia/reperfusion (n = 96) groups. There were 6 time points in the ischemia/reperfusion group, comprising 4, 6, 12, 24, 48, and 72 hours after reperfusion, with 16 rats for each time point. Rat models in the sham-operated group at 4 hours after surgery and rat models in the ischemia/reperfusion group at different time points were equally and randomly assigned into 4 different subgroups. MAIN OUTCOME MEASURES: Brain water content on the ischemic side and the control side was measured using the dry-wet weight method. Blood-brain barrier function was determined by Evans Blue. Aquaporin-4 expression surrounding the ischemic focus, as well as the correlation of aquaporin-4 expression with brain water content and Evans blue staining, were measured using immunohistochemistry and Western blot analysis. RESULTS: Brain water content on the ischemic side significantly increased at 12 hours after reperfusion, reached a peak at 48 hours, and was still high at 72 hours. Brain water content was greater on the ischemic hemispheres, compared with the control hemispheres at 6, 12, 24, 48, and 72 hours after reperfusion, as well as both hemispheres in the sham-operated group (P<0.05). Evans blue content significantly increased on the ischemic side at 4 hours after ischemi',dreperfusion, and reached a peak at 48 hours. Evans blue content was greater on the ischemic hemispheres, compared with the control hemispheres at various time points, as well as both hemispheres in the sham-operated group (P<0.05). Aquaporin-4-positive cells were detected in the cortex and hippocampus, surrounding the ischemic penumbra focus, at 4-6 hours after ischemia/reperfusion. The number of positive cells significantly increased at 12 hours and reached a peak at 48-72 hours. Aquaporin-4 was, however, weakly expressed in the control hemispheres and the sham-operated group. The absorbance ratio of aquaporin-4 to β-actin was greater at 12, 24, 48, and 72 hours following cerebral ischemia/reperfusion, compared with the sham-operated group (P<0.05). Aquaporin-4 expression positively correlated to brain water content and Evans blue staining following cerebral ischemia/reperfusion (r1 = 0.68, r2= 0.81, P<0.05). CONCLUSION: Aquaporin-4 is highly expressed in brain tissues, participates in the occurrence of ischemic brain edema, and is positively correlated to blood-brain barrier permeability following cerebral ischemia/reperfusion.     

蛛网膜下腔出血后早期海马ADAMTS-1的表达与血脑屏障通透性的相关性研究

目的研究大鼠蛛网膜下腔出血(subarachnoid hemorrhage,SAH)后早期海马组织中ADAMTS-l(a disintegrin-like and metalloproteinase with thrombospondin type l motifs)表达情况及其与血脑屏障通透性的关系,初步探讨ADAMTS-l在实验性大鼠SAH后早期脑损伤(early brain injury,EBI)中的作用。方法成年雄性SD大鼠108只,分假手术组和SAH组。采用大鼠视交叉前池注血模型,于SAH后6、12、24、48、72 h时间点,应用Western-Blotting和RT-PCR法检测大鼠海马ADAMTS-1蛋白及mRNA表达变化,同时应用甲酰胺浸泡法检测大鼠脑内伊文氏蓝(Evans blue,EB)含量。结果大鼠SAH后6 h、12 h组海马ADAMTS-1mRNA及蛋白表达与sham组相比无统计学意义,于出血后24 h表达明显升高,48 h达到高峰,72 h后仍维持在较高水平。脑内伊文氏蓝含量亦于出血后24 h明显升高,48 h达到高峰并于72 h仍维持在较高水平。ADAMTS-1蛋白表达与脑内EB含量成正相关(r=0.936,P=0.014)。结论大鼠SAH后早期脑损伤过程中ADAMTS-l的表达与血脑屏障损伤成正相关,提示ADAMTS-l可能参与SAH后早期脑损伤的病理过程。     

Peripheral thermal injury causes early blood–brain barrier dysfunction and matrix metalloproteinase expression in rat

Abstract

High mortality incidence after serious systemic thermal injury is believed to be linked to significant increases in cerebral permeability, ultimately leading to irreversible blood–brain barrier (BBB) breakdown. The aim of this study was to investigate whether disruption of microvascular integrity in a rat thermal injury model is associated with early matrix metalloproteinase (MMP) expression.

A total of 35 Sprague–Dawley rats were studied in thermal injury and control groups, each group containing two subgroups, one for brain edema and Evans blue analysis and another for MMP mRNA analysis. Thermally injured animals were anesthetized and submerged vertically in 85°C water to the neck for 6 seconds producing a third degree burn affecting 70% of the total body surface area. BBB integrity was determined by measuring amount of Evans blue after 7 hours of injury with a spectrophotometer. Brain edema was detected by calculating water content. Brain mRNA levels were determined with real-time PCR 3 and 7 hours post-injury.

Brain water content was significantly increased after peripheral injury at hour 7. Evans blue leakage was also significantly increased at the same time, suggesting an impaired BBB function after injury. Expressions of MMP-2 and MMP-9 mRNA in brain were increased as early as 3 hours after injury and remained at hour 7.

Our study demonstrated a significant increase in cerebral permeability that occurs after serious systemic thermal injury. The underlying mechanisms could be related to early expression of MMPs.     

大鼠脑挫裂伤半暗带水肿与血-脑屏障破坏的关系

目的研究大鼠局灶性脑挫裂伤半暗带的水肿变化与血-脑屏障(BBB)破坏的关系。方法将126只雄性SD大鼠随机分为3组:假手术组、挫裂伤组和给药组,采用Feeney法制作脑挫裂伤模型,给药组采用曲克芦丁脑蛋白水解物合剂腹腔给药,分别用伊文思蓝(EB)染色法和干湿法观察BBB的变化和脑组织的水肿情况,同时电镜观察超微结构。结果EB染色显示:挫裂伤组和给药组在伤后1 h EB开始漏出,6 h最严重。水含量测定结果显示:挫裂伤组和给药组伤后6 h水含量开始增加,72 h增至高峰。与挫裂伤组比较,给药组脑组织EB溢出量、水含量降低(P<0.05)。结论大鼠脑挫裂伤半暗带BBB通透性改变早于脑水肿的发生,提示BBB破坏可能是早期创伤性脑水肿的结构基础。曲克芦丁脑蛋白水解物合剂可通过改善BBB等多种途径治疗脑挫裂伤。     

Treatment with sodium orthovanadate reduces blood-brain barrier disruption via phosphatase and tensin homolog deleted on chromosome 10 (PTEN) phosphorylation in experimental subarachnoid hemorrhage

Attenuation of blood-brain barrier (BBB) disruption is one of the therapeutic candidates for treatment of subarachnoid hemorrhage (SAH). In this study, the protective effect of sodium orthovanadate (SOV) on BBB disruption was investigated in SAH using the endovascular perforation model. Fifty-five rats were randomly assigned to sham-operated, SAH treated with saline (as a vehicle), or 10 mg/kg SOV groups and were evaluated for neurofunction and Evans blue dye extravasation. The phosphorylation of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) and mitogen-activated protein kinase (MAPK) and the expression of matrix metalloproteinase-9 (MMP-9), occludin, and collagen-IV were examined by Western blot analyses. Cell death among endothelial cells was revealed by immunofluorescence and terminal deoxynucleotidyl transferase-mediated uridine 5'-triphosphate-biotin nick end-labeling staining. SOV significantly improved neurofunction and reduced Evans blue dye extravasation in brains after SAH. SOV phosphorylated PTEN, decreased phospho-JNK and MMP-9, and preserved occludin expression. SOV also attenuated SAH-induced capillary endothelial cell death. The current study showed that SOV was protective against BBB disruption after SAH, possibly via PTEN phosphorylation.     

实验性脑出血灶周MMP-9的表达与脑水肿的关系

目的探讨脑出血（ICH）后出血灶周脑组织MMP-9表达的动态变化,分析其与脑水肿的关系。方法健康雄性Sprauge-Dawley（SD）大鼠56只,分为正常组（8只）和手术组（48只）,手术组选择出血后12、24、48、72、96、120h共6个时间点,每点各8只。在脑立体定向仪下采用自体动脉血注入尾状核法制备脑出血模型。用免疫组化法和RT-PCR法检测MMP-9的表达水平;用干湿重法测量脑含水量（BWC）;用测定渗出脑血管外的EB量来评价BBB的通透性,电镜观察神经元形态变化。结果ICH灶周脑组织MMP-9的表达在48h达峰值,脑水肿于72h达峰值,两者呈正相关（r=0．698,P〈0．01）。电镜观察到血管周围水肿,神经元水肿。结论MMP9参与了ICH后灶周脑组织水肿的过程,诱导或加重脑水肿。     

Neuritin attenuates early brain injury in rats after experimental subarachnoid hemorrhage

Objectives: Early brain injury (EBI) is central to the pathological progress of subarachnoid hemorrhage (SAH). In this study, we determined if neuritin protects the brain against EBI in rats and discussed the role of apoptosis pathway mediated by endoplasmic reticulum stress in this neuroprotective route. Methods: A total of 96 male Sprague Dawley rats were divided into control, sham, SAH and SAH + neuritin groups. The rat SAH model was induced by injection 0.3 mL of nonheparinized arterial blood into the prechiasmatic cistern. Mortality assay, neurological scores, brain water content measurement, Evans blue dye assay, TUNEL stain assay and Western blot analysis were performed. Results: Neuritin significantly improved the neurological scores, brain water content, blood-brain barrier (BBB) and apoptosis compared with the control and sham groups within 24 h after SAH. TUNEL staining assay results demonstrated that apoptosis was ameliorated, MMP-9 expression was reduced, whereas GRP78, CHOP, caspase-12 and ASK1 levels were markedly preserved after neuritin application. Conclusions: Our study demonstrated that neuritin plays a neuroprotective role on EBI after SAH by attenuating BBB disruption, brain edema and apoptosis.