Effects of electroacupuncture preconditioning on microglial cells and serum inflammatory factors in the early stage of ischemic stroke

OBJECTIVES

To investigate the effects on the motor function, cortex blood flow perfusion, microglial cells, and the contents of serum inflammatory factors, i.e. interleukin-1β (IL-1β), transforming growth factor-β (TGF-β), and interleukin-10 (IL-10) after electroacupuncture (EA) preconditioning at "Baihui" (GV20) and "Dazhui" (GV14) in the mice with ischemic stroke, so as to explore the mechanism of EA preconditioning for improving motor function after ischemic stroke.

METHODS

C57BL/6 mice were randomly divided into sham-operation group, model group, and EA preconditioning group (EA group), with 15 mice in each group. A photothrombotic method was used to induce the model of unilateral ischemic stroke and motor impairment. The mice in the EA group received EA preconditioning, 20 min each time, once daily for 7 consecutive days before modeling. The motor function of mice was evaluated by the grid-walking test and cylinder test before and after modeling. Laser speckle blood flow video monitoring system was employed to assess the cerebral blood flow perfusion in the primary motor cortex of mice. The contents of IL-1β, TGF-β, and IL-10 in the serum were measured by ELISA, and the expressions of microglial cell and M2 subtype cell marker in the primary motor cortex were detected using immunofluorescence staining.

RESULTS

After modeling, compared with the sham-operation group, the grid error rate and the dragging rate of the affected limb were increased (P<0.01)；the utilization rate of the affected limb and percentage of the blood perfusion in the affected cortex to healthy side were decreased (P<0.01)；the contents of serum IL-1β, TGF-β, and IL-10 were increased (P<0.01, P<0.05)；and the microglia in the primary motor cortex on the affected side showed ameboid, the fluorescence intensity of ionized calcium-binding adapter molecule 1 (IBA1) and CD206 was increased (P<0.01) in the model group. In the EA group, when compared with the model group, the grid error rate and the dragging rate of affected limb were decreased (P<0.01)；the utilization rate of affected limb and the percentage of blood perfusion were increased (P<0.05)；the content of serum IL-1β was decreased (P<0.01), while the contents of TGF-β and IL-10 were increased (P<0.01)；and the microglia in the primary motor cortex on the affected side got more round and were distributed more densely, the fluorescence intensity of IBA1 and CD206 was increased (P<0.01).

CONCLUSIONS

Electroacupuncture preconditioning at "GV20" and "GV14" can up-regulate the expression of microglial cells, especially the M2 subtype cell marker, and increase the contents of the anti-inflammatory factors and decrease that of the pro-inflammatory factors in the serum, thereby alleviate the inflammatory reaction.

Electroacupuncture preconditioning protects against myocardial ischemia-reperfusion injury by modulating dynamic inflammatory response

Background

The protective effects of electroacupuncture (EA) preconditioning against myocardial ischemia-reperfusion injury (MIRI) have been reported. However, the underlying mechanism remains unclear. Recent research has indicated that the dynamic inflammatory response following MIRI plays an essential role in the progression of myocardial injury. This study aimed to investigate the myocardial protective effects of EA preconditioning on MIRI in rats and to explore the relevant mechanism from the perspective of dynamic inflammatory response.

Methods

A MIRI model was employed, and the rats were subjected to EA on Neiguan for four days prior to modeling. The myocardial protective effect of EA preconditioning was evaluated by echocardiography, Evans blue and triphenyltetrazolium chloride staining. Real-time polymerase chain reaction, Western blot, hematoxylin & eosin staining, and immunohistochemistry were utilized to detect the content of mitochondrial DNA, NOD receptor family protein 3 (NLRP3) inflammasome activation, neutrophil recruitment and macrophage infiltration in blood samples and myocardium below the ligation.

Results

We found that EA preconditioning could accelerate the recovery of left ventricle function after MIRI and reduce the myocardial infarction area, thereby protecting the myocardium against MIRI. Furthermore, EA preconditioning was observed to ameliorate mitochondrial impairment, reduce the level of plasma mitochondrial DNA, modulate NLRP3 inflammasome activation, attenuate neutrophil infiltration, and promote the polarization of M1 macrophages towards M2 macrophages in the myocardium after MIRI.

Conclusion

EA preconditioning could reduce plasma mtDNA, suppress overactivation of the NLRP3 inflammasome, facilitate the transition from the acute pro-inflammatory phase to the anti-inflammatory reparative phase after MIRI, and ultimately confer cardioprotective benefits.

[Effect of different electrical current intensities of electroacupuncture preconditioning on cardiac function and macrophage polarization in mice with acute myocardial ischemia]

OBJECTIVE

To observe the effect of different intensities of electroacupuncture (EA) preconditioning on car-diac function and polarization state of macrophages in mice with acute myocardial ischemia (AMI), so as to explore its possible mechanism underlying improvement of AMI.

METHODS

A total of 50 male C57BL/6J mice were randomly divided into sham ope-ration, AMI model, and EA pretreatment groups (0.5 mA, 1 mA, 3 mA subgroups), with 10 mice in each group/subgroup. The mice in the EA pretreatment groups were subjected to EA stimulation of bilateral "Neiguan"(PC6) with 0.5, 1.0 and 3 mA respectively and frequency of 2 Hz/15 Hz for 20 min, once a day, for 3 days. The acute myocardial ischemia model was established by ligating the anterior descending branch (ADB) of the left coronary artery, while the sham operation only had a surgical suture trans-passed below the ADB but without ligation. The myocardial infarction area was measured after TTC staining, and the cardiac function ［left ventricular ejection fraction (EF), short-axis contraction rate (FS)］ was detected by using echocardiography. The M1 macrophages were labeled with CD11b+F480+CD206^low, M2 macrophages were labeled with CD11b+F480+CD206^high and detected by using flow cytometry, and the expression levels of myocardial interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), Toll-like receptor-4 (TLR4) proteins were detected by using Western blot.

RESULTS

Compared with the sham operation group, the model group had a significant increase in the infarction area (P<0.000 1), number of cardiac macrophages and percentage of M1 type macrophages (P<0.000 1), and the expression levels of myocardial IL-1β, TNF-α, TLR4 proteins (P<0.001, P<0.01), and a remarkable decrease in the levels of EF, FS and the percentage of M2 type macrophages (P<0.000 1). In contrast to those of the model group, the area of myocardial infarction (P<0.000 1, P<0.01), expression levels of myocardial IL-1β, TNF-α, TLR4 proteins (P<0.01, P<0.05, P<0.001) in the 0.5 mA, 1 mA and 3 mA groups, number of macrophages and percentage of M1 macrophages (P<0.05) in the 1 mA group were significantly decreased, while the levels of EF and FS (P<0.000 1, P<0.05, P<0.001) in the 3 EA groups, and percentage of M2 macrophage (P<0.05) in the 1 mA group were significantly increased. Comparison among the 3 EA groups displayed that the effects of 1 mA group were significantly superior to those of 0.5 and 3 mA groups in up-regulating EF and FS (P<0.01, P<0.001), and in down-regulating the area of infarct myocardium (P<0.01, P<0.000 1), and the expression of TLR4 protein (P<0.01), and 0.5 mA group in the expression of IL-1β and TNF-α proteins (P<0.05).

CONCLUSION

EA preconditioning with electrical current intensities of 0.5 mA, 1 mA and 3 mA can effectively reduce myocardial infarction size, improve cardiac function in mice with AMI, which may be related with its effects in reducing the number of cardiac macrophages and down-regulating the expression of myocardial IL-1β, TNF-α and TLR4 proteins. The therapeutic effect of 1 mA is better than that of 0.5 and 3 mA.

[Electroacupuncture preconditioning alleviates renal injury and oxidative stress through Sirt3/MnSOD pathway in type 2 diabetic rats]

OBJECTIVE

To explore the protective effect and molecular mechanism of electroacupuncture (EA) preconditioning on renal injury in type 2 diabetic rats.

METHODS

Fifty male Wistar rats were randomly divided into control, model, EA, EA+inhibitor, and inhibitor groups, with 10 rats in each group. Diabetes model was established by high fat and high glucose diet and intraperitoneal injection of streptozotocin (40 mg/kg). EA (2 Hz, 1 mA) preconditioning was applied to "Guanyuan" (CV4), "Zhongwan" (CV12), bilateral "Zusanli" (ST36) and "Fenglong" (ST40) for 15 min, once every other day for 8 weeks. Rats of the inhibitor and EA+inhibitor groups were given intraperitoneal injection of 3-TYP (50 mg/kg) once every other day for a total of 3 times. The body weight, kidney mass, and renal index were recorded. The contents of urine microalbumin (ALB), 24 h urine 8-hydroxydeoxyguanosine (8-OHdG) and activities of reactive oxygen species (ROS), superoxide dismutase (SOD), catalase (CAT), glutathione glycine peroxidase (GSH-Px) in kidney were detected by ELISA. The activities of mitochondrial respiratory chain enzyme complex (RCCⅠ-RCCⅣ) in kidney were detected using spectrophotometric method. HE staining, Masson staining and transmission electron microscopy were used to observe the changes of renal structure. The protein and mRNA expressions of silent information regulator 3 (Sirt3), manganese superoxide dismutase (MnSOD) in kidney were detected by Western blot and quantitative real-time PCR, respectively.

RESULTS

After modeling and compared with the control group, the contents of ALB, the renal index, activity of ROS and content of 8-OHdG, and the renal collagen volume fraction (CVF) were increased (P<0.01), while the activities of SOD, CAT and GSH-Px, RCCⅠ-RCCⅣ, and the mRNA and protein expressions of Sirt3 and MnSOD were decreased (P<0.01). After the treatment and compared with the model group, the contents of ALB, the renal index, ROS, 8-OHdG, and the CVF were decreased in the EA group(P<0.01, P<0.05), while the activities of SOD, CAT, GSH-Px, RCCⅠ-RCCⅣ, and Sirt3 and MnSOD expression levels were increased (P<0.01, P<0.05)；the RCCⅡ activity and the expression level of MnSOD mRNA were increased (P<0.05) in the EA+inhibitor group; the ALB and 8-OHdG contents and the CVF in the inhibitor group were increased (P<0.05), while the activity of SOD, and Sirt3 and MnSOD expression levels were decreased (P<0.05). In comparison with the EA group, the contents of ALB, the renal index, activities of ROS and 8-OHdG contents, and the CVF were increased (P<0.05, P<0.01), activities of SOD, CAT and GSH-Px and RCCⅠ and RCCⅡ, and the mRNA and protein expressions of Sirt3 and MnSOD were decreased (P<0.05, P<0.01) in both EA+inhibitor group and inhibitor group, whereas the activities of RCCⅢ and RCCⅣ were decreased in the inhibitor group (P<0.05). The therapeutic effect of inhibitor was notably inferior to that of EA+inhibitor in decreasing ALB and 8-OHdG contents, and CVF (P<0.01), and in up-regulating SOD and RCCⅡ activities, Sirt3 and MnSOD expression levels (P<0.01, P<0.05).

CONCLUSION

EA preconditioning can increase the expressions of renal Sirt3 and MnSOD in type 2 diabetic rats, thereby reducing the oxidative stress response and protecting the kidneys.

[Electroacupuncture preconditioning improves pulmonary function via inhibiting inflammatory response and up-regulating expression of ACE2 and Ang (1-7) in lipopolysaccharide-induced acute lung injury rats]

OBJECTIVE

To observe the effect of electroacupuncture (EA) at "Zusanli"(ST36) pretreatment on lung functions, inflammatory response, and levels of angiotensin-converting enzyme 2 (ACE2) and angiotensin (1-7) ［Ang (1-7)］ in rats with sepsis-induced acute lung injury (ALI), so as to explore its mechanisms underlying improvement of ALI.

METHODS

Thirty male SD rats were randomly divided into normal, model and EA groups (n=10 in each group). The sepsis-related ALI model was established by intraperitoneal injection of lipopolysaccharide (LPS, 5 mg/kg). Rats of the EA group received EA (4 Hz/20 Hz, 1-3 mA) stimulation at bilateral ST36 for 30 min, once each day, for 7 days before modeling. The lung functions including forced vital capacity (FVC), forced expiratory volume at 0.1 second (FEV0.1) and FEV0.3 were detected using a respiratory function detector for small animals at 3 h after modeling. The bronchoalveolar lavage fluid (BALF) was collected for assaying the contents of Ang (1-7), tumor necrosis factor-α (TNF-α) and interleukin-1 β (IL-1β) using ELISA. The lung wet/dry weight (W/D) ratio, FEV0.1/FVC, and FEV0.3/FVC were calculated. The histopathological changes of lung tissues were displayed by hematoxylin-eosin (H.E.) staining. The expression of ACE2 and mitochondrial assembly receptor (MasR) mRNAs and proteins in the lung tissue was detected by fluorescence quantitative real-time PCR and Western blot, separately.

RESULTS

Following modeling, the levels of FVC, FEV0.1, FEV0.3, ratio of FEV0.1/FVC and FEV0.3/FVC, content of Ang (1-7) in the BALF, and the expression levels of ACE2 and MasR mRNAs and proteins in the lung tissue were significantly decreased (P<0.01), while the level of W/D ratio and TNF-α and IL-1β contents in the BALF significantly increased (P<0.01) in the model group relevant to the normal group. In comparison with the model group, the levels of FVC, FEV0.1, FEV0.3, ratio of FEV0.1/FVC and FEV0.3/FVC, content of Ang (1-7) in the BALF, and expression levels of ACE2 and MasR mRNAs and proteins in the lung tissue were significantly increased (P<0.05, P<0.01), whereas the level of W/D ratio, and TNF-α and IL-1β contents in the BALF were significantly decreased (P<0.05, P<0.01) in the EA group. H.E. staining showed pulmonary interstitial edema and alveolar septum thickening with severe inflammatory cell infiltration in the model group, which was relatively milder in the EA group.

CONCLUSION

EA preconditioning at ST36 can improve pulmonary function in sepsis-related ALI rats, which may be related to its effects in inhibiting inflammatory response and up-regulating ACE2 and MasR expression and Ang (1-7) content in the lung tissue.

[Effect of electroacupuncture preconditioning on expression of Gasdermin D, Caspase-1 and IL-1β in rats with myocardial ischemia reperfusion injury]

OBJECTIVE

To observe the effect of electroacupuncture(EA) preconditioning on expression of Caspase-1, Gasdermin D(GSDMD) and interleukin-1β(IL-1β) in myocardial tissue of myocardial ischemia reperfusion injury (MIRI) rats in order to explore its underlying mechanisms in resisting MIRI.

METHODS

Forty male rats were randomly divided into 4 groups: normal control (normal), sham operation (sham), MIRI model and EA groups. The MIRI model was established by ligation of the left anterior descending branch of the left coronary artery for 30 min and perfusion. EA (2 Hz/100 Hz, 1 mA) was applied to bilateral "Neiguan" (PC6) for 20 min, once a day for 3 consecutive days. The echocardiography was used to analyze the left ventricular end-diastolic dimension (LVEDD), left ventricular end-systolic dimension (LVESD) and left ventricular ejection fraction (LVEF, by using Teichholz formula) 4 h after modeling. The myocardial TTC staining was used to observe the proportion of the infarct area, and Western blot was used to detect the expression levels of GSDMD, Caspase-1, IL-1β proteins in the myocardium.

RESULTS

Compared with the normal group, the immunoactivity of GSDMD was increased in the sham group (P<0.05). Compared with the sham group, the LVEF was significantly decreased (P<0.000 1), while the myocardial infarction area, immunoactivity of GSDMD, and the expression levels of Caspase-1, GSDMD and IL-1β proteins were considerably increased in the model group (P<0.000 1, P<0.001). In comparison with the model group, the decreased ejection fraction and the increased myocardial infarction area, and Caspase-1, GSDMD and IL-1β expression were reversed in the EA group (P<0.001, P<0.000 1, P<0.01).

CONCLUSION

EA preconditioning may ameliorate myocardial injury in MIRI rats which may be associated with its function in down-regulating the expression of myocardial Caspase-1 protein to reduce cardiomyocyte pyroptosis.

[Electroacupuncture preconditioning alleviates kidney injury in hyperglycemic mice]

OBJECTIVE

To explore the protective effect and molecular mechanism of electroacupuncture (EA) preconditioning on renal injury induced by streptozotocin (STZ) in hyperglycemic mice.

METHODS

Eighty male C57BL/6 mice were randomly divided into 4 groups: control, model, EA and sham EA groups, n=20 in each group. The hyperglycemic model was established by intraperitoneal injection of 0.1% STZ solution (50 mg/kg) for 5 days. EA preconditioning or sham EA was applied at "Zusanli" (ST36) and "Shenshu" (BL23), once daily for 7 successive days in the EA or sham EA group. Three days after mode-ling, the blood glucose was measured after fasting for 6 hours. The degree of renal injury was observed by HE staining and PAS staining; the expressions of transient receptor potential cation channel 6 (TRPC6) and Nephrin protein in glomerulus were observed by immunohistochemistry; the expressions of TRPC6 and Nephrin protein in renal cortex were detected by Western blot.

RESULTS

Compared with the control group, the blood glucose level was significantly increased (P<0.01), the glomerular cross-sectional area was apparently increased (P<0.000 1), the glomerular capillaries dilated, the matrix proliferated, the brush edge of renal tubules disappeared, the proportion of abnormal renal tubules increased (P<0.000 1), and the expressions of TRPC6 and Nephrin in glomeruli and renal tissue were significantly increased (P<0.01) in the model group. Following EA treatment and compared with the model and sham EA groups, the blood glucose was significantly down-regulated (P<0.01), the renal tissue injury was apparently alleviate, the cross-sectional area of glomerulus was reduced (P<0.05), the brush edge of renal tubules changes were obviously improved, the proportion of abnormal renal tubules decreased (P<0.000 1), and the expressions of TRPC6 and Nephrin in glomerulus and renal tissue decreased (P<0.05) in the EA group.

CONCLUSION

EA preconditioning can alleviate renal injury in hyperglycemic mice, which is closely related to its effects in reducing renal TRPC6 and Nephrin expressions and inhibiting podocyte activation.

Electroacupuncture pretreatment alleviates myocardial injury through regulating mitochondrial function

Background

Electroacupuncture is well known for its advantageous neuroanalgesic and therapeutic effects on myocardial ischemia–reperfusion injury. The purpose of the present research was to verify whether electroacupuncture can alleviate bupivacaine-induced myocardial injury.

Methods

Specific pathogen-free Wistar rats were used to establish the bupivacaine-induced myocardial injury model. Western blot, PCR, transmission electron microscope and enzyme-linked immunosorbent (ELISA) methods were used to evaluate bupivacaine-induced structure injury and dysfunction of the mitochondria as well as the alleviating effects of lipid emulsion, acupoint injection, and electroacupuncture pre-treatment of the oxidase stress response.

Results

Bupivacaine caused structural damage, degradation, and swelling of mitochondria. Furthermore, it reduced adenosine triphosphate (ATP) synthesis and impaired energy metabolism in the mitochondria. Structural and functional impairment of the mitochondria was alleviated via lipid emulsion injection, acupoint injection, and electroacupuncture pre-treatment. Electroacupuncture pre-treatment of PC6 yielded a greater alleviating effect than others approaches. Following electroacupuncture pre-treatment of PC6 point, the number of mitochondria increased; apoptosis was reduced, enzymatic activity of cytochrome C oxidase (COX) and superoxide dismutase and expression of uncoupling protein 2, voltage-dependent anion channel 1, and Bcl 2 were upregulated and SLC25A6, MDA levels were downregulated. Additionally, our findings indicated that electroacupuncture pre-treatment of PC6 point exerted an effect on the mitochondria via the mitochondrial-transcription-factor-A/nuclear-respiratory-factor-1/proliferator-activated-receptor-gamma-coactivator-1 pathway.

Conclusion

The present study revealed that electroacupuncture pre-treatment of PC6 could effectively alleviate bupivacaine-induced myocardial mitochondrial damage, thereby providing a theoretical basis for clinical studies and applications of this treatment method.

Electroacupuncture preconditioning attenuates myocardial ischemia-reperfusion injury by inhibiting mitophagy mediated by the mTORC1-ULK1-FUNDC1 pathway

Myocardial ischemia/reperfusion (I/R) is an important complication of reperfusion therapy for myocardial infarction, and trimetazidine is used successfully for treatment of ischemic cardiomyopathy by regulating mitochondrial function. Moreover, electroacupuncture (EA) preconditioning was demonstrated to be cardioprotective in both in vivo rodent models and in patients undergoing heart valve replacement surgery. However, the mechanisms have not been well elucidated. Mitophagy, mediated by the mTORC1-ULK1-FUNDC1 (mTOR complex 1-unc-51-like autophagy-activating kinase 1-FUN14 domain-containing 1) pathway, can regulate mitochondrial mass and cell survival effectively to restrain the development of myocardial ischemia/reperfusion injury (MIRI). In this study, we hypothesized that EA preconditioning ameliorated MIRI via mitophagy. To test this, rapamycin, an mTOR inhibitor, was used. The results showed that EA preconditioning could reduce the infarct size and risk size, and decrease the ventricular arrhythmia score and serum creatine kinase-myocardial band isoenzyme (CK-MB), lactate dehydrogenase (LDH), and cardiac troponin T (cTnT) in MIRI rats. Moreover, it also attenuated MIRI-induced apoptosis and mitophagy accompanied by elevated mTORC1 level and decreased ULK1 and FUNDC1 levels. However, these effects of EA preconditioning were blocked by rapamycin, which aggravated MIRI, reduced adenosine triphosphate (ATP) production, and antagonized infarct size reduction. In conclusion, our results indicated that EA preconditioning protected the myocardium against I/R injury by inhibiting mitophagy mediated by the mTORC1-ULK1-FUNDC1 pathway.

[Effect of electroacupuncture preconditioning on neurological deficit and expression of cerebral Cx43 protein in rats with acute cerebral infarction]

OBJECTIVE

To observe the effect of electroacupuncture (EA) on expression of cerebral Cx43 protein in acute cerebral infarction (ACI) rats so as to explore its mechanisms underlying improvement of ACI.

METHODS

Sixty male SD rats were randomly divided into sham operation, model and EA preconditioning groups (n＝20 in each group). Fourteen days before modeling, the rats in the EA preconditioning group accepted EA stimulation (3 Hz/15 Hz, 1 mA) at Dingzhongxian (MS5) and Dingpangxian (MS8) for 30 min, once daily, 6 times a week for 2 weeks. The ACI model was established by occlusion of the middle cerebral artery for 120 min, followed by reperfusion. Twenty-four hours after modeling, the neurological function was evaluated according to the Zea-Longa's score criteria. The triphenyltetrazolium chloride (TTC) staining method was used to detect the cerebral infarct volume. The expression levels of Cx43, phosphorylated (p)-Cx43 and PKC proteins in the right cerebral cortical infarction region were detected by Western blot.

RESULTS

The neurological function scores and the infarct volume were significantly higher in the model group than those in the sham operation group (P<0.05), and obviously lower in the EA preconditioning group than in the model group (P<0.05). The expression level of cerebral Cx43 protein was significantly increased (P<0.05), and those of p-Cx43 and PKC proteins were notably decreased in the model group relevant to the sham operation group (P<0.05). In the EA preconditioning group, the expression level of Cx43 was significantly decreased and those of p-Cx43 and PKC proteins were significantly increased than those in the model group (P<0.05).

CONCLUSION

EA pretreatment can relieve neurological damage and reduce cerebral infarction volume in ACI rats, which may be related to its function in promoting Cx43 protein phosphorylation via up-regulating PKC expression in the ischemic cerebral region.

[Development of research on mechanisms of electroacupuncture intervention underlying improvement of cerebral ischemia rats in recent five years]

In the present paper, we summarized the relevant research literature on the underlying mechanism of electroacupuncture (EA) intervention in improving cerebral ischemia (CI) in middle cerebral artery occlusion (MCAO) model rats in recent 5 years from preconditioning and regular intervention. Outcomes showed that both EA preconditioning and regular intervention could relieve CI by reducing toxicity of excitatory amino acids (glutamate, aspartate) and TLR4/NF-κB-mediated inflammatory cascade reaction to relieve inflammatory injury. Moreover, EA preconditioning also could suppress the expression of pro-apoptosis genes and proteins to relieve apoptosis, regulate activation of microglia, and down-regulate the expression of blood brain barrier integrity-related matrix metalloprotein 9. Regular EA intervention also could promote angiogenesis to increase supply of blood and oxygen, facilitate regeneration, proliferation and differentiation of neural stem cells via triggering activation of Notch and Shh signaling pathways, and promote the secretion of neurotrophin by up-regulating the expression of brain derived neurotrophic factor and nerve growth factor /Trk A receptor, and promote expression of axon growth and synaptic remodeling-related factor (Ephrin B2/Eph B2) and sr-GTPase activating protein 1 and cell division cycle 42 (Cdc42, axon growth and orientated down-stream molecules). However, up to now, the conclusion is still fragmentary and one-sided, and can not explain the specific mechanism of electroacupuncture in MCAO rats, needing further in-depth study.

[Serum metabolic profile involving protective effect of "Neiguan"(PC6)-electroacupuncture preconditioning in rats with myocardial ischemia reperfusion injury]

OBJECTIVE

To observe the effect of "Neiguan" (PC6)-electroacupuncture (EA) preconditioning on serum metabolites in myocardial ischemia-reperfusion injury (MIRI) rats, so as to reveal its mechanism underlying improvement of ischemic myocardium from metabonomics.

METHODS

A total of 48 male SD rats were randomly divided into control, model, EA "Neiguan"(PC6) and EA "Hegu"(LI4) groups (n＝12 rats/ group). Rats of the control group were just banded on animal boards for 30 min, once daily for 7 days. The MIRI model was established by occlusion of the left anterior descending branch of the left coronary artery for 40 min, followed by reperfusion for 1 h, and rats of the model group were also banded as those in the control group. Before modeling, EA (10 Hz/50 Hz, 1 mA) was applied to bilateral "Neiguan"(PC6) and "Hegu"(LI4) for 30 min, once daily for 7 successive days. After the treatment, serum samples were collected to be analyzed by proton nuclear magnetic resonance (¹H NMR) spectroscopy. The orthogonal partial least squares discriminate analysis (PLS-DA) was employed to distinguish the serum differential metabolic profile of rats in different groups and identify potential biomarkers.

RESULTS

After modeling, the ECG of model group and electroacupuncture groups showed T wave towering, and there was no obvious ST segment between R wave and T wave. The T wave decreased more than 0.2 mV after reperfusion, and there was no obvious ST segment. Compared with the control group, MIRI induced significant changes of metabolites in the serum including increase of acetoacetate acid, lectic acid, creatine, glycerol and glucose, and decrease of alanine, glutamine, glycerophosphoryl choline and phosphorylcholine. In comparison with the model group, PC6-EA preconditioning induced significant changes, including an increase of glucose, and a decrease of leucine，isoleucine, valine，3-hydroxybutyric acid，lactate，acetate，acetone，acetoacetate acid，pyruvic acid，glutamine，creatine and glycerol. There is no significant difference in metabolic patterns between "Hegu" group and model group. Metabolic pathway enrichment analysis indicated that the protective effect of PC6-EA pretreatment was realized mainly by regulating pathways of glycolysis, gluconeogenesis, citric acid metabolism, pyruvate metabolism, ketone body metabolism, etc.

CONCLUSION

PC6-EA pretreatment has a role in regulating gluconeogenesis, pyruvate metabolism, amino metabolism, ketone body metabolism and energy metabolism in rats with MIRI, which maybe contribute to its protective effect on ischemic myocardium, but the specific metabolic pathways and mechanisms need being studied further.

Effects of electroacupuncture preconditioning on jugular vein glucose level and cerebral edema in rats undergoing cerebral ischemia reperfusion that induced injury

OBJECTIVE

To determine the effects of electroacupuncture (EA) preconditioning on the blood glucose level in jugular vein and water content in brain tissues in rats undergoing cerebral ischemia reperfusion that induced injury.

METHODS

90 healthy male Wister rats were randomly assigned to 3 groups: sham-operation (SH) group, cerebral ischemia reperfusion (IR) group and electroacupuncture (EA) preconditioning plus IR group. EA group was pretreated with EA delivered to acupoints of "Baihui" (Du 20) and "Shuigou" (Du 26) 30 min before cerebral ischemia.

RESULTS

No marked difference was observed in brain water content 2 h after procedure in IR group, SH group and EA group. Compared with SH group, the brain water contents in IR group and EA group were significantly higher 6 h after reperfusion and peaked at 48 h (P < 0.01). The blood glucose levels in EA and IR groups were significantly higher than that of SH group 2 h after reperfusion, which peaked at 6 h and tended to decline up to 24 h after reperfusion (P < 0.01). 2 h, 6 h, and 24 h after reperfusion, EA group had significantly lower blood glucose levels than IR group (P < 0.01).

CONCLUSION

Electroacupuncture preconditioning can significantly inhibit the augmentation of the blood glucose level and attenuate cerebral edema induced by reperfusion, which leads to alleviation of injury caused by ischemia reperfusion.