Protective effect of ginkgo proanthocyanidins against cerebral ischemia/reperfusion injury associated with its antioxidant effects

Proanthocyanidins have been shown to effectively protect ischemic neurons, but its mechanism remains poorly understood. Ginkgo proan-thocyanidins (20, 40, 80 mg/kg) were intraperitoneally administered 1, 24, 48 and 72 hours before reperfusion. Results showed that ginkgo proanthocyanidins could effectively mitigate neurological disorders, shorten infarct volume, increase superoxide dismutase activity, and de-crease malondialdehyde and nitric oxide contents. Simultaneously, the study on grape seed proanthocyanidins (40 mg/kg) conifrmed that different sources of proanthocyanidins have a similar effect. The neurological outcomes of ginkgo proanthocyanidins were similar to that of nimodipine in the treatment of cerebral ischemia/reperfusion injury. Our results suggest that ginkgo proanthocyanidins can effectively lessen cerebral ischemia/reperfusion injury and protect ischemic brain tissue and these effects are associated with antioxidant properties.     

Oxidative phosphorylated neurofilament protein M protects spinal cord against ischemia/reperfusion injury

Previous studies have shown that neurofilament protein M expression is upregulated in the early stage of spinal cord ischemia/reperfusion injury, indicating that this protein may play a role in the injury process. In the present study, we compared protein expression in spinal cord tissue of rabbits after 25 minutes of ischemia followed by 0, 12, 24, or 48 hours of reperfusion with that of sham operated rabbits, using proteomic two-dimensional gel electrophoresis and mass spec- trometry. In addition, the nerve repair-related neurofilament protein M with the unregulated expression was detected with immunohistochemistry and western blot analysis. Two-dimen- sional gel electrophoresis and mass spectrometry showed that, compared with the sham group, upregulation of protein expression was most significant in the spinal cords of rabbits that had undergone ischemia and 24 hours of reperfusion. Immunohistochemical analysis revealed that neurofilament protein M was located in the membrane and cytoplasm of neuronal soma and axons at each time point after injury. Western blot analysis showed that neurofilament protein M expression increased with reperfusion time until it peaked at 24 hours and returned to baseline level after 48 hours. Furthermore, neurofilament protein M is phosphorylated under oxidative stress, and expression changes were parallel for the phosphorylated and non-phosphorylated forms. Neurofilament protein M plays an important role in spinal cord ischemia/reperfusion injury, and its functions are achieved through oxidative phosphorylation.     

Pretreatment with scutellaria baicalensis stem-leaf total flavonoid protects against cerebral ischemia/ reperfusion injury in hippocampal neurons

Previous experimental studies have shown that cerebral infarction can be effectively reduced following treatment with scutellaria baicalensis stem-leaf total flavonoid （SSTF）. However, the mechanism of action of SSTF as a preventive drug to treat cerebral infarction remains unclear. In this study, Sprague-Dawley rats were pretreated with 50, 100, 200 mg/kg SSTF via intragastric ad- ministration for 1 week prior to the establishment of focal cerebral ischemia/reperfusion injury. The results showed that pretreatment with SSTF effectively improved neurological function, reduced brain water content and the permeability of blood vessels, ameliorated ischemia-induced morphology changes in hippocampal microvessels, down-regulated Fas and FasL protein expression, elevated the activity of superoxide dismutase and glutathione peroxidase, and decreased malondialdehyde content. In contrast to low-dose SSTF pretreatment, the above changes were most obvious after pretreatment with moderateand high-doses of SSTF. Experimental findings indicate that SSTF pretreatment can exert protective effects on the brain against cerebral ischemia/reperfusion injury. The underlying mechanisms may involve reducing brain water content, increasing microvascular recanalization, inhibiting the apoptosis of hippocampal neurons, and attenuating free radical damage.     

Neuroprotective effect ofShenqi Fuzheng injection pretreatment in aged rats with cerebral ischemia/reperfusion injury

Shenqi Fuzheng injection is extracted from the Chinese herbs Radix Astragali and Radix Codonopsis. The aim of the present study was to investigate the neuroprotective effects of Shenqi Fuzheng injection in cerebral ischemia and reperfusion. Aged rats(20–22 months) were divided into three groups: sham, model, and treatment. Shenqi Fuzheng injection or saline(40 m L/kg) was injected into the tail vein daily for 1 week, after which a cerebral ischemia/reperfusion injury model was established. Compared with model rats that received saline, rats in the treatment group had smaller infarct volumes, lower brain water and malondialdehyde content, lower brain Ca2+ levels, lower activities of serum lactate dehydrogenase and creatine kinase, and higher superoxide dismutase activity. In addition, the treatment group showed less damage to the brain tissue ultrastructure and better neurological function. Our findings indicate that Shenqi Fuzheng injection exerts neuroprotective effects in aged rats with cerebral ischemia/reperfusion injury, and that the underlying mechanism relies on oxygen free radical scavenging and inhibition of brain Ca2+ accumulation.     

Neuronal apoptosis in cerebral ischemia/reperfusion area following electrical stimulation of fastigial nucleus

Previous studies have indicated that electrical stimulation of the cerebellar fastigial nucleus in rats may reduce brain infarct size, increase the expression of Ku70 in cerebral ischemia/ reperfusion area, and decrease the number of apoptotic neurons. However, the anti-apoptotic mechanism of Ku70 remains unclear. In this study, fastigial nucleus stimulation was given to rats 24, 48, and 72 hours before cerebral ischemia/reperfusion injury. Results from the electrical stim- ulation group revealed that rats exhibited a reduction in brain infarct size, a significant increase in the expression of KuT0 in cerebral ischemia/reperfusion regions, and a decreased number of terminal deoxynucleotidyl transferase dUTP nick end labeling （TUNEL）-positive cells. Double immunofluorescence staining revealed no co-localization of Ku70 with TUNEL-positive cells. However, Ku70 partly co-localized with Bax protein in the cytoplasm of rats with cerebral ischemia/reperfusion injury. These findings suggest an involvement of Ku70 with Bax in the cy- toplasm of rats exposed to electrical stimulation of the cerebellar fastigial nucleus, and may thus provide an understanding into the anti-apoptotic activity of KuT0 in cerebral ischemia/reperfu- sion injury.     

13-Methyltetradecanoic acid mitigates cerebral ischemia/reperfusion injury

13-Methyltetradecanoic acid can stabilize cell membrane and have anti-inlfammatory, antioxidant and anti-apoptotic effects. Previous studies mainly focused on peripheral nerve injury, but seldom on the central nervous system. We investigated whether these properties of 13-methyltetradecanoic acid have a neuroprotective effect on focal cerebral ischemia/reperfusion injury, and detected the expression of basic ifbroblast growth factor and vascular endothelial growth factor. This study established rat models of middle cerebral artery occlusion/reperfusion injury by ischemia for 2 hours and reperfusion for 24 hours. At the beginning of reperfusion, 13-methyltetradecanoic acid 10, 40 or 80 mg/kg was injected into the tail vein. Results found that various doses of 13-methyltetradecanoic acid effectively reduced infarct volume, mitigate cerebral edema, and increased the mRNA and protein expression of basic ifbroblast growth factor and vascular endothe-lial growth factor at 24 hours of reperfusion. The effect was most signiifcant in the 13-methyltetradecanoic acid 40 and 80 mg/kg groups. The ifndings suggest that 13-methyltetradecanoic acid can relieve focal ischemia/reperfusion injury immediately after reperfusion, stimu-late the upregulation of basic ifbroblast growth factor and vascular endothelial growth factor to exert neuroprotective effects.     

Neuroprotective effects of rutaecarpine on cerebral ischemia reperfusion injury**

Rutaecarpine,an active component of the traditional Chinese medicine Tetradium ruticarpum,has been shown to improve myocardial ischemia reperfusion injury.Because both cardiovascular and cerebrovascular diseases are forms of ischemic vascular disease,they are closely related.We hypothesized that rutaecarpine also has neuroprotective effects on cerebral ischemia reperfusion injury.A cerebral ischemia reperfusion model was established after 84,252 and 504 μg/kg rutaecarpine were given to mice via intraperitoneal injection,daily for 7 days.Results of the step through test,2,3,5-triphenyl tetrazolium chloride dyeing and oxidative stress indicators showed that rutaecarpine could improve learning and memory ability,neurological symptoms and reduce infarction volume and cerebral water content in mice with cerebral ischemia reperfusion injury.Rutaecarpine could significantly decrease the malondialdehyde content and increase the activities of superoxide dismutase and glutathione peroxidase in mouse brain.Therefore,rutaecarpine could improve neurological function following injury induced by cerebral ischemia reperfusion,and the mechanism of this improvement may be associated with oxidative stress.These results verify that rutaecarpine has neuroprotective effects on cerebral ischemia reperfusion in mice.     

Puerarin protects brain tissue against cerebral ischemia/reperfusion injury by inhibiting the inflammatory response

Puerarin, a traditional Chinese medicine, exerts a powerful neuroprotective effect in cerebral ischemia/reperfusion injury, but its mechanism is unknown. Here, we established rat models of middle cerebral artery ischemia/reperfusion injury using the suture method. Puerarin(100 mg/kg) was administered intraperitoneally 30 minutes before middle cerebral artery occlusion and 8 hours after reperfusion. Twenty-four hours after reperfusion, we found that puerarin significantly improved neurological deficit, reduced infarct size and brain water content, and notably diminished the expression of Toll-like receptor-4, myeloid differentiation factor 88, nuclear factor kappa B and tumor necrosis factor-α in the ischemic region. These data indicate that puerarin exerts an anti-inflammatory protective effect on brain tissue with ischemia/reperfusion damage by downregulating the expression of multiple inflammatory factors.     

An optimal dose of tea polyphenols protects against global cerebral ischemia/reperfusion injury

Previous studies addressing the protection of tea polyphenols against cerebral ischemia/ reperfusion injury often use focal cerebral ischemia models, and the optimal dose is not unified. In this experiment, a cerebral ischemia/reperfusion injury rat model was established using a modified four-vessel occlusion method. Rats were treated with different doses of tea polyphenols (25, 50, 100, 150, 200 mg/kg) via intraperitoneal injection. Results showed that after 2, 6, 12, 24, 48 and 72 hours of reperfusion, peroxide dismutase activity and total antioxidant capacity in brain tissue gradually increased, while malondialdehyde content gradually decreased after tea polyphenol intervention. Tea polyphenols at 200 mg/kg resulted in the most apparent changes. Terminal deoxynucleotidyl transferase-mediated nick end labeling and flow cytometry showed that 200 mg/kg tea polyphenols significantly reduced the number and percentage of apoptotic cells in the hippocampal CA1 region of rats after cerebral ischemia/reperfusion injury. The open field test and elevated plus maze experiments showed that tea polyphenols at 200 mg/kg strengthened exploratory behavior and reduced anxiety of cerebral ischemia/reperfusion injured rats. Experimental findings indicate that tea polyphenols protected rats against cerebral ischemia/ reperfusion injury and 200 mg/kg is regarded as the optimal dose.     

Neuroprotective effect of pretreatment with ganoderma lucidum in cerebral ischemia/reperfusion injury in rat hippocampus

Ganoderma lucidum is a traditional Chinese medicine,which has been shown to have both anti-oxidative and anti-inflammatory effects,and noticeably decreases both the infarct area and neuronal apoptosis of the ischemic cortex.This study aimed to investigate the protective effects and mechanisms of pretreatment with ganoderma lucidum(by intragastric administration)in cerebral ischemia/reperfusion injury in rats.Our results showed that pretreatment with ganoder-ma lucidum for 3 and 7 days reduced neuronal loss in the hippocampus,diminished the content of malondialdehyde in the hippocampus and serum,decreased the levels of tumor necrosis fac-tor-αand interleukin-8 in the hippocampus,and increased the activity of superoxide dismutase in the hippocampus and serum.These results suggest that pretreatment with ganoderma lucidum was protective against cerebral ischemia/reperfusion injury through its anti-oxidative and an-ti-inflammatory actions.     

Dose-dependent effects of procyanidin on nerve growth factor expression following cerebral ischemia/ reperfusion injury in rats★

BACKGROUND： Recently, grape seed procyanidin （GSP） has been shown to be exhibit antioxidant effects, effectively reducing ischemia/reperfusion injury and inhibiting brain cell apoptosis. OBJECTIVE： To study the effects of GSP on nerve growth factor （NGF） expression and neurological function following cerebral ischemia/reperfusion injury in rats. DESIGN： Randomized controlled study based on SD rats. SETTING： Weifang Municipal People＇s Hospital. MATERIALS： Forty-eight healthy adult SD rats weighing 280-330 g and irrespective of gender were provided by the Experimental Animal Center of Shandong University. GSP derived from grape seed was a new high-effective antioxidant provided by Tianjin Jianfeng Natural Product Researching Company （batch number： 20060107）. Rabbit-anti-rat NGF monoclonal antibody was provided by Beijing Zhongshan Biotechnology Co., Ltd., and SABC immunohistochemical staining kit by Wuhan Boster Bioengineering Co., Ltd. METHODS： The present study was performed in the Functional Laboratory of Weifang Medical College from April 2006 to January 2007. Forty-eight SD rats were randomly divided into the sham operation group, ischemia/reperfusion group, high-dose GSP （40 mg/kg） group, or low-dose GSP （10 mg/kg） group （n = 12 per group）. Ischemia/reperfusion injury was established using the threading embolism method of the middle cerebral artery. Rats in the ischemia/reperfusion model group were given saline injection （2 mL/kg i.p.） once daily for seven days pre-ischemia/reperfusion, and once more at 15 minutes before reperfusion. Rats in the high-dose and low-dose GSP groups were injected with GSP （20 or 5 mg/mL i.p., respectively, 2 mL/kg） with the same regime as the ischemia/reperfusion model group. The surgical procedures in the sham operation group were as the same as those in the ischemia/reperfusion model group, but the thread was approximately 10 mm long, thus, the middle cerebral artery was not blocked. MAIN OUTCOME MEASURES： NGF expression in the     

麻黄碱干预脑缺血再灌注损伤的不良反应：不同剂量比较

Ephedrine has protective effect to rats suffered from cerebral ischemia, the aim of the present study was to evaluate the side effects of ephedrine on heart, liver, kidney and cerebrum of rats after ischemic-reperfusion. Sprague-Dawley (SD) rats, suffered from ischemic-reperfusion were randomly divided into 4 groups: A group for ephedrine, B group for ephedrine, C group for ephedrine, and control group （D group）.At each week, hematoxylin eosin staining was used to observe the tissue of all the organs, then, the blood pressure, aspartate aminotransferase (AST), alkaline phosphatase (AKP) and creatinine were tested, also immunohistochemical method was used to test the expression of brain-derived neurotrophic factor (BDNF) on hippocampal CA3 area. The blood pressure values were lower in ephedrine groups than those in control group all the time (P<0.05). The biochemistry results showed that AST、AKP and serum creatinine in ephedrine groups were higher than those in control groups (P<0.05). The expression levels of BDNF on hippocampal CA3 area in ephedrine groups were higher than that in control group at the last three weeks (P<0.05). The pathological section showed that in all the ephedrine groups, we can see congestion, degeneration and edema of tissues. These findings indicate that ephedrine may have side effects on heart, liver, kidney and cerebrum in ischemic/reperfusion rats. There may be correlation between the side effects and dose, the side effects are enhanced with an increased dose of ephedrine. The injury of the above organs also may be transient, which can be recovered after discontinuation of treatment.     

Neuroprotection of Chrysanthemum indicum Linne against cerebral ischemia/reperfusion injury by anti-inflammatory effect in gerbils

In this study, we tried to verify the neuroprotective effect of Chrysanthemum indicum Linne(CIL) extract, which has been used as a botanical drug in East Asia, against ischemic damage and to explore the underlying mechanism involving the anti-inflammatory approach. A gerbil was given CIL extract for 7 consecutive days followed by bilateral carotid artery occlusion to make a cerebral ischemia/reperfusion model. Then, we found that CIL extracts protected pyramidal neurons in the hippocampal CA1 region(CA1) from ischemic damage using neuronal nucleus immunohistochemistry and Fluoro-Jade B histofluorescence. Accordingly, interleukin-13 immunoreactivities in the CA1 pyramidal neurons of CIL-pretreated animals were maintained or increased after cerebral ischemia/reperfusion. These findings indicate that the pre-treatment of CIL can attenuate neuronal damage/death in the brain after cerebral ischemia/reperfusion via an anti-inflammatory approach.     

Neuroprotective effect of Cerebralcare Granule after cerebral ischemia/reperfusion injury

Cerebralcare Granule(CG) improves cerebral microcirculation and relieves vasospasm,but studies investigating its therapeutic effect on cerebral ischemia/reperfusion injury are lacking.In the present study,we administered CG(0.3,0.1 and 0.03 g/m L intragastrically) to rats for 7 consecutive days.We then performed transient occlusion of the middle cerebral artery,followed by reperfusion,and administered CG daily for a further 3 or 7 days.Compared with no treatment,high-dose CG markedly improved neurological function assessed using the Bederson and Garcia scales.At 3 days,animals in the high-dose CG group had smaller infarct volumes,greater interleukin-10 expression,and fewer interleukin-1β-immunoreactive cells than those in the untreated model group.Furthermore,at 7 days,high-dose CG-treated rats had more vascular endothelial growth factor-immunoreactive cells,elevated angiopoietin-1 and vascular endothelial growth factor expression,and improved blood coagulation and flow indices compared with untreated model animals.These results suggest that CG exerts specific neuroprotective effects against cerebral ischemia/reperfusion injury.     

Effect of nicorandil on infarct volume and marker enzyme activity in mitochondria of rats with cerebral ischemia/ reperfusion injury★

BACKGROUND： Recent studies have suggested that mitochondrial ATP-sensitive K＋ channel openers could reduce myocardium infarct size, and protect the function of the mitochondria. OBJECTIVE： To investigate the changes of cerebral infarction volume and the activity of marker enzymes in brain mitochondria of rats given the ATP-sensitive K＋ channel opener, nicorandil, before focal cerebral ischemia/reperfusion （I/R）. DESIGN, TIME AND SETTING： Randomized, controlled animal experiment, completed at the Brain Scientific Research Center of the Affiliated Hospital of Qingdao University from July to November 2007. MATERIALS： Sixty healthy male Wistar rats weighing 280-300 g. Nicorandil, 5-hydroxydecanoate （5-HD） and cytochrome C were purchased from Sigma in the USA. Standard malondialdehyde （MDA） and protein were purchased from Nanjing Jiancheng Biotechnology Institute. METHODS： Sixty rats were randomly divided into a sham operation group, a middle cerebral artery occlusion （MCAO） group, a nicorandil group and a nicorandil＋5-HD group. MCAO for 2 hours was performed in the MCAO group, nicorandil group and nicorandil＋5-HD group. A total of 5 mL saline were given to the MCAO group before MCAO. The nicorandil group was injected with the ATP-sensitive K＋ channel opener nicorandil 10 mg/kg intraperitoneally 30 minutes before MCAO. The nicorandil＋5-HD group was injected with 5-HD 10 mg/kg intravenously 15 minutes before the same treatment as the nicorandil group. MAIN OUTCOME MEASURES： Infarct volume by total brain slice calculation, activities of succinate dehydrogenase （SDH） and cytochrome oxidase （CO）, and content of MDA were observed at 22 hours of reperfusion after 2 hours MCAO. RESULTS： Sixty rats were included in the final analysis, without any loss. （1） Infarct volume： compared with the MCAO group and nicorandil＋5-HD group, the percentage of infarct volume was significantly decreased in the nicorandil group （P 〈 0.01）. （2） The content of MDA, expression of     

Effect of nicorandil on infarct volume and marker enzyme activity in mitochondria of rats with cerebral ischemia/ reperfusion injury

BACKGROUND: Recent studies have suggested that mitochondrial ATP-sensitive K channel openers could reduce myocardium infarct size, and protect the function of the mitochondria.OBJECTIVE: To investigate the changes of cerebral infarction volume and the activity of marker enzymes in brain mitochondria of rats given the ATP-sensitive K channel opener, nicorandil, before focal cerebral ischemia/reperfusion (I/R).DESIGN, TIME AND SETTING: Randomized, controlled animal experiment, completed at the Brain Scientific Research Center of the Affiliated Hospital of Qingdao University from July to November 2007.MATERIALS: Sixty healthy male Wistar rats weighing 280-300g. Nicorandil, 5-hydroxydecanoate (5-HD) and cytochrome C were purchased from Sigma in the USA. Standard malondialdehyde (MDA) and protein were purchased from Nanjing Jiancheng Biotechnology Institute.METHODS: Sixty rats were randomly divided into a sham operation group, a middle cerebral artery occlusion (MCAO) group, a nicorandil group and a nicorandil 5-HD group. MCAO for 2 hours was performed in the MCAO group, nicorandil group and nicorandil 5-HD group. A total of 5mL saline were given to the MCAO group before MCAO. The nicorandil group was injected with the ATP-sensitive K channel opener nicorandil 10mg/kg intraperitoneally 30 minutes before MCAO. The nicorandil 5-HD group was injected with 5-HD 10mg/kg intravenously 15 minutes before the same treatment as the nicorandil group.MAIN OUTCOME MEASURES: Infarct volume by total brain slice calculation, activities of succinate dehydrogenase (SDH) and cytochrome oxidase (CO), and content of MDA were observed at 22 hours of reperfusion after 2 hours MCAO.RESULTS: Sixty rats were included in the final analysis, without any loss. (1) Infarct volume: compared with the MCAO group and nicorandil 5-HD group, the percentage of infarct volume was significantly decreased in the nicorandil group (P<0.01). (2) The content of MDA, expression of SDH and CO in brain: the expressions of SDH and CO in the sham operation group were significantly lower than those in the MCAO, nicorandil and nicorandil 5-HD groups (P<0.01). The expressions of SDH and CO in the nicorandil group were significantly higher than those in the MCAO and nicorandil 5-HD groups (P<0.05). The content of MDA in the brain of the nicorandil group was significantly lower than those in the MCAO and nicorandil 5-HD groups (P<0.01).CONCLUSION: Nicorandil can significantly reduce the infarct volume in a rat MCAO model, increase the activity of the mitochondria and protect against cerebral I/R injury.     

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 280-320g, 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 10mm, 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 model group than in the TCST group (P<0.05). Twenty four hours after cerebral ischemia/reperfusion, SOD activities were lower, whereas MDA contents and NO levels were higher in the TCST and model groups, compared with the sham operation group (P<0.05 or P<0.01). Compared with the model group, SOD activities were higher, whereas MDA contents and NO levels were lower in the TCST group (P<0.05).CONCLUSION: After TCST, cerebral infarct volume is reduced, SOD activities are increased, and MDA contents and NO levels are decreased compared to the model group in rats with focal cerebral ischemia/reperfusion injury. These changes may be associated with TCST.     

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