scholarly journals Electroacupuncture Ameliorates Cognitive Impairment through Inhibition of Ca2+-Mediated Neurotoxicity in a Rat Model of Cerebral Ischaemia–reperfusion Injury

2018 ◽  
Vol 36 (6) ◽  
pp. 401-407 ◽  
Author(s):  
Yun Zhang ◽  
Xiang Mao ◽  
Ruhui Lin ◽  
Zuanfang Li ◽  
Jing Lin

Background The hippocampus is vulnerable to severe damage after cerebral ischaemia–reperfusion (I/R) injury. This study aimed to explore the effect of electroacupuncture (EA) on cognitive impairment and its relationship with Ca2+neurotoxicity in a rat model of I/R injury induced by middle cerebral artery occlusion (MCAO). Methods 60 adult male Sprague-Dawley rats were randomly divided into three groups: control (sham surgery) group, untreated MCAO group and EA-treated MCAO+EA group. Rats in the MCAO and MCAO+EA groups underwent modelling of poststroke cognitive impairment by MCAO surgery. EA was performed for 30 min daily at GV20 and GV24 (1–20 Hz) for 1 week. The Morris water maze experiment was used to assess cognitive function. 2,3,5-triphenyl tetrazolium chloride staining was used to measure infarct volume. The intracellular Ca2+content in the Cornu Ammonis (CA)1 area of the hippocampus was assessed by laser confocal scanning microscopy. ELISA was performed to evaluate the concentration of glutamate (Glu) in the hippocampus, and the protein expression of two Glu receptors (N-methyl-D-aspartic acid receptor (NMDAR) 2A and NMDAR2B) were analysed by Western blotting. Results Compared with the untreated MCAO group, EA effectively ameliorated cognitive impairment (P=0.01) and shrunk the infarct volume (P=0.032). The content of intracellular Ca2+, Glu and NMDAR2B in the hippocampus was significantly raised by MCAO (P=0.031-0.043), while EA abrogated these effects. NMDAR2A was decreased by MCAO (P=0.015) but increased by EA (P=0.033). Conclusions EA had a beneficial effect on cognitive repair after cerebral I/R, and its mechanism of action likely involves a reduction of Ca2+influx via inhibition of Glu neurotoxicity and downregulation of NMDAR2B expression.

2015 ◽  
Vol 33 (6) ◽  
pp. 478-484 ◽  
Author(s):  
Fang Liu ◽  
Yi-Jing Jiang ◽  
Hong-Jia Zhao ◽  
Li-Qun Yao ◽  
Li-Dian Chen

Background Post-stroke cognitive impairment seriously affects the quality of life and functional rehabilitation of patients with stroke. Objective To examine the effects of electroacupuncture (EA) at GV20 and GV24 on cognitive impairment and apoptosis including expression of apoptosis-related genes Bcl-2 and Bax in a rat model of cerebral ischaemia-reperfusion (IR) induced by middle cerebral artery occlusion (MCAO). Methods Thirty-five Sprague-Dawley rats were allocated to a sham operation control group (SC group, n=10) or underwent surgery and MCAO (n=25). Postoperatively the latter group was randomly subdivided into EA or untreated (IR) groups. Cognitive impairment was assessed using the Morris water maze (MWM). Apoptosis was examined by detection of Bcl-2 and Bax expression in the cerebral cortex. Results The EA group had significantly decreased neurological deficit scores compared to the IR group (p<0.05). In the MWM test, significant differences in escape latency and route were observed between the EA and IR groups (p<0.05). Rats in the EA group performed better in the probe trial than those in the IR group (p<0.05). EA treatment markedly reduced the number of TUNEL-positive cells compared to the IR group (20.13±4.30% vs 38.40±3.38%; p<0.001). Reverse transcription-polymerase chain reaction (RT-PCR) results showed the Bcl-2/Bax ratio was significantly increased in the EA group compared to the IR group (1.61±0.19 vs 0.50±0.05, p<0.01). Conclusions These findings suggest that EA ameliorates cognitive impairment of rats with IR injury by modulating Bcl-2 and Bax expression.


2009 ◽  
Vol 102 (11) ◽  
pp. 837-845 ◽  
Author(s):  
Sara Castiglia ◽  
Marco Manoni ◽  
Liana Salsini ◽  
Jacopo Chini ◽  
Emanuela Masini ◽  
...  

SummaryHeparin and low molecular weight heparins may reduce brain damage evoked by ischaemia/reperfusion (I/R) injury, although their use is hampered by the risk of haemorrhage. Chemical and enzymatic modifications of K5 polysaccharide have shown the possibility to produce heparin-like compounds with low anticoagulant activity and strong anti-inflammatory effects. Using a rat model of transient cerebral I/R, we investigated the effects of an epimerised N-,O-sulfated K5 polysaccharide derivative, K5-N,OSepi, on the infarct size, motor activity and injury caused by ischaemia (30 min) and reperfusion. Reperfusion was allowed for 60 min or 1–5 days. Rats reperfused for 5 days showed an infarct volume of 30.7 ±3.1% and K5-N,OSepi (0.1–1 mg/kg) caused dose-dependent reduction in infarct size (maximum at 1 mg/kg: 13.1 ±2.1% infarct volume). This effect was associated with a significant improvement in motor performance. In the rat hippocampus, one of the brain areas most sensitive to I/R injury, I/R induced a robust increase in myeloperoxidase (MPO) activity, a marker of neutrophil infiltration, that was halved by K5-N,OSepi administration (66.38 ±7.75 µU MPO/tissue g, 30.78 ±5.67 µU MPO/tissue g, respectively). K5-N,OSepi drastically reduced the expression of cyclooxygenase-2,inducible-nitric-oxide-synthase and intercellular-adhesion-molecule-1. I/R-induced activation of nuclear factor-kB was attenuated by drug treatment. Furthermore, K5-N,OSepi administration was associated with a significant modulation of apoptosis markers, such as Bid and Bcl-2. In conclusion, the results demonstrated that the sulfated semi-synthetic K5 derivative K5-N,OSepi protects the brain against I/R injury by disrupting multiple levels of the apoptotic and inflammatory cascade, including inhibition of NF-κB activation.


2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Lingguang Liu ◽  
R. T. F. Cheung

Both melatonin and electroacupuncture (EA) have been suggested to be effective treatments against stroke. However, it is unknown whether a combination of these two therapies could be beneficial against transient focal cerebral ischemia. The present study investigated the effects of pretreatment of a combination of melatonin and EA in a rat model of transient middle cerebral artery occlusion (MCAO). After pretreatment of melatonin plus EA (MEA), transient MCAO was induced for 90 minutes in male Sprague-Dawley (SD) rats. The neurological deficit score, brain infarct volume, cerebral edema ratio, neuronal inflammation, and apoptosis were evaluated 24 hours after transient MCAO. The expression of related inflammatory and apoptotic mediators in the brain was also investigated. The results showed that MEA improved neurological outcome, reduced brain infarct volume, and inhibited neuronal inflammation as well as apoptosis 24 hours after transient MCAO. The beneficial effects may derive from downregulation of proinflammatory and proapoptotic mediators and upregulation of antiapoptotic mediators. Thus, these results suggest a preventive effect of pretreatment of MEA on transient focal cerebral ischemia.


2006 ◽  
Vol 111 (6) ◽  
pp. 373-380 ◽  
Author(s):  
Ismail H. Mallick ◽  
Marc C. Winslet ◽  
Alexander M. Seifalian

IR (ischaemia/reperfusion) injury of the intestine occurs commonly during abdominal surgery. We have previously shown that PDTC (pyrrolidine dithiocarbamate), an HO-1 (haem oxygenase-1) donor, improves intestinal microvascular perfusion. In the present study, we have investigated the effects of PDTC on the intestinal microcirculation following IR (ischaemia/reperfusion) injury of the intestine. Male Sprague–Dawley rats (n=72) were randomly assigned to four groups (n=18/group): (i) sham-operated group, who underwent laparotomy without induction of IR of the intestine; (ii) IR group, who were subjected to 30 min of superior mesenteric artery occlusion and 2 h of reperfusion; (iii) PDTC+IR group, who received PDTC prior to IR; and (iv) ZnPP group, who received the HO-1 inhibitor ZnPP (zinc protoporphyrin) followed by procedures as in group (iii). The ileum was evaluated for changes in tissue cytochrome c oxidase redox status, RBC (red blood cell) dynamics and leucocyte–endothelial interactions. The expression of HO-1 in the ileal tissue was examined at the end of the reperfusion. PDTC significantly improved the intestinal tissue oxygenation, mucosal perfusion index and RBC velocity compared with the IR and ZnPP groups. PDTC also decreased the leucocyte–endothelial interactions (P<0.05 compared with the IR and ZnPP groups). PDTC induced the expression of HO-1, whereas ZnPP abolished this effect.


2013 ◽  
Vol 25 (1) ◽  
pp. 12-17 ◽  
Author(s):  
Pei-Lei Zhang ◽  
Hai-Tao Lu ◽  
Jun-Gong Zhao ◽  
Ming-Hua Li

ObjectiveTo investigate the effect of dl-3n-butylphthalide (NBP) on the protection of cerebral tissue and possible mechanism on ischaemia-reperfusion injury, and to find out whether NBP therapy can extend the reperfusion window in an experimental stroke model in rats.MethodsSeventy-two Sprague-Dawley rats were randomly divided into sham operation, ischaemia-reperfusion and ischaemia-reperfusion with NBP groups. Focal cerebral ischaemia was induced using the modified intraluminal thread method and maintained for 2, 3 or 4 h. The ischaemia-reperfusion group received reperfusion immediately after ischaemia-reperfusion. The NBP group received intraperitoneal injection of NBP immediately after ischaemia, followed by reperfusion. The sham operation group received only injection of physiological saline. The cerebral infarction volume and neurological deficit were analysed, and vascular endothelial growth factor (VEGF) expression in brain tissues was visualised by immunohistochemistry.ResultsNBP treatment caused a significant decrease in both infarction volume and neurological deficit compared with the ischaemia-reperfusion group at corresponding time points in each (p < 0.05). In the NBP group, the infarction volume and neurological deficit did not change with different ischaemia times. The expression of VEGF was significantly decreased in the ischaemia-reperfusion group compared with the sham group (p < 0.01), while this change was partly prevented in the NBP group (p < 0.01). The expression of VEGF in brain tissue in both the NBP and ischaemia-reperfusion groups gradually decreased when the ischaemic period was prolonged.ConclusionNBP treatment has a protective effect against cerebral ischaemia; this possible mechanism maybe related to the VEGF expression and may extend the reperfusion window for subsequent salvage of cerebral ischaemia by reperfusion.


Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Christopher Sy ◽  
Xiaokun Geng ◽  
Paul Fu ◽  
Changya Peng ◽  
Vance Fredrickson ◽  
...  

Objectives: Normobaric oxygenation (NBO) has been reported to be neuroprotective against acute cerebral ischemia. Recently, a clinical trial was terminated because beneficial outcomes were not definitive. Our recent study ( Stroke. 2012 43(1):205-10 ) demonstrated a strong neuroprotective effect induced by acute administration of ethanol (EtOH) at 1.5g/kg. In this study, we assessed the therapeutic influence of EtOH in combination with NBO. Methods: Sprague-Dawley rats were subjected to right middle cerebral artery occlusion for 2h. Ischemic animals received either an intraperitoneal injection of EtOH (1.0g/kg), a course of NBO (100% for 2h), or a combination of both immediately prior to reperfusion onset. Brain injury was determined by infarct volume and behavioral outcomes at 48h post-reperfusion. Metabolic dysfunction was investigated by assessing ADP/ATP ratios, reactive oxygen species (ROS) levels, NADPH oxidase (NOX) activity, and protein expression of NOX subunits (p47 phox , gp91 phox , and p67 phox ), as well as the protein expression and enzyme activity of pyruvate dehydrogenase (PDH), at both 3h and 24h after reperfusion. Results: Combination therapy led to a significant decrease in infarct volumes (Saline: 48±4%, EtOH: 38±3%, NBO: 37±4%, Combination: 19±3% ) and in neurological deficits (Belayev Scale 0-12, Saline: 8.4±0.7; EtOH: 6.5±0.7; NBO: 6.4±0.6; Combination: 4.4±0.3 ). At 3h and 24h post-reperfusion the decrease in ADP/ATP ratio was significantly enhanced, reflecting a preservation of cellular energy. A greater decrease in NOX activity and protein expression was observed, in association with decreased ROS levels, suggesting that improved glycolysis may contribute to neuroprotection. PDH activity and protein expression was dramatically increased, making the facilitation of aerobic metabolism a probable mechanism for preserving cellular ATP. Conclusions: Our findings demonstrate that a synergistic relationship exists between EtOH and NBO. Both are promising neuroprotective agents when used together, even at low doses. Moreover, both are inexpensive, widely available, easy to administer, and have little side effects. Thus, combination therapy could be an effective and efficient approach to future stroke treatments.


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