Focal Ischemia-reperfusion Injury Research Articles

Assessment of focal renal ischemia-reperfusion injury in a porcine model using hyperpolarized [1-13 C]pyruvate MRI.

Ischemic injury in the kidney is a common pathophysiological event associated with both acute kidney injury and chronic kidney disease; however, regional ischemia-reperfusion as seen in thromboembolic renal disease is often undetectable and thus subclinical. Here, we assessed the metabolic alterations following subclinical focal ischemia-reperfusion injury with hyperpolarized [1-13 C]pyruvate MRI in a porcine model. Five pigs were subjected to 60 min of focal kidney ischemia. After 90 min of reperfusion, a multiparametric proton MRI protocol was performed on a clinical 3T scanner system. Metabolism was evaluated using 13 C MRI following infusion of hyperpolarized [1-13 C]pyruvate. Ratios of pyruvate to its detectable metabolites (lactate, bicarbonate, and alanine) were used to quantify metabolism. The focal ischemia-reperfusion injury resulted in injured areas with a mean size of 0.971 cm3 (±1.019). Compared with the contralateral kidney, the injured areas demonstrated restricted diffusion (1269 ± 83.59 × 10-6 mm2 /s vs. 1530 ± 52.73 × 10-6 mm2 /s; p=0.006) and decreased perfusion (158.8 ± 29.4 mL/100 mL/min vs. 274 ± 63.1 mL/100 mL/min; p=0.014). In the metabolic assessment, the injured areas displayed increased lactate/pyruvate ratios compared with the entire ipsilateral and the contralateral kidney (0.35 ± 0.13 vs. 0.27 ± 0.1 vs. 0.25 ± 0.1; p=0.0086). Alanine/pyruvate ratio was unaltered, and we were unable to quantify bicarbonate due to low signal. MRI with hyperpolarized [1-13 C]pyruvate in a clinical setup is capable of detecting the acute, subtle, focal metabolic changes following ischemia. This may prove to be a valuable future addition to the renal MRI suite.

Выраженность когнитивных и неврологических нарушений у крыс после ишемического инсульта на фоне применения ксенона 0,5 МАК

The majority of stroke patients have cognitive symptoms and about 50% of them live with neurological deficits that critically limit social adaptation capacities even in the absence of significant motor impairments. The aim of this study was to select the optimal length of 0.5 MAC xenon exposure in order to alleviate the neurological and cognitive impairments in experimental stroke. The focal ischemia-reperfusion injury was modeled in rats (n = 70) ising Longa method. The intervention was immediately followed by inhalation of 0.5 MAC xenon for 30, 60 or 120 min. The neurological deficit was assessed using a 'Limb placement' seven-test battery and the cognitive functionalities were assessed by the Morris water maze test. A 30 min 0.5 MAC xenon exposure provided a 40% increase in the limb placement scores and a 17.6% decrease in the Morris water maze test latency compared with the control group (р = 0.055 and р = 0.08, respectively). With a longer 60 min exposure, the trends became significant, the scores improving 2-fold and by 44.4% compared with the control group (р = 0.01 and р = 0.04, respectively), whereas 120 min exposures afforded 2-fold improvements in both tests (р = 0.01). We conclude that, although 30 min post-stroke inhalations provide negligible benefits in terms of neurological status and learning capacity, prolonged exposure times of 60–120 min afford significant improvement in neurological and cognitive indicators and largely alleviate the deteriorating ischemic damage.

Neuroprotective Effects of GV1001 in Animal Stroke Model and Neural Cells Subject to Oxygen-Glucose Deprivation/Reperfusion Injury.

Background and Purpose Previous studies have revealed the diverse neuroprotective effects of GV1001. In this study, we investigated the effects of GV1001 on focal cerebral ischemia-reperfusion injury (IRI) in rats and oxygen-glucose deprivation/reoxygenation (OGD/R)-induced injury in neural stem cells (NSCs) and cortical neurons. Methods Focal cerebral IRI was induced by transient middle cerebral artery occlusion (MCAO). Brain diffusion-weighted imaging (DWI) was performed 2 hours after occlusion, and a total of 37 rats were treated by reperfusion with GV1001 or saline 2 hours after occlusion. Fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging, immunohistochemistry, and neurobehavioral function analyses were performed. Additionally, OGD/R-injured NSCs and cortical neurons were treated with different GV1001 concentrations. Cell viability, proliferation, migration, and oxidative stress were determined by diverse molecular analyses. Results In the stroke model, GV1001 protected neural cells against IRI. The most effective dose of GV1001 was 60 μM/kg. The infarct volume on FLAIR 48 hours after MCAO compared to lesion volume on DWI showed a significantly smaller ratio in the GV1001-treated group. GV1001-treated rats exhibited better behavioral functions than the saline-treated rats. Treatment with GV1001 increased the viability, proliferation, and migration of the OGD/R-injured NSCs. Free radicals were significantly restored by treatment with GV1001. These neuroprotective effects of GV1001 have also been demonstrated in OGD/R-injured cortical neurons. Conclusions The results suggest that GV1001 has neuroprotective effects against IRI in NSCs, cortical neurons, and the rat brain. These effects are mediated through the induction of cellular proliferation, mitochondrial stabilization, and anti-apoptotic, anti-aging, and antioxidant effects.

Correction to: Protective Effect of Mitogen- and Stress-Activated Protein Kinase (MSK) on Focal Ischemia-Reperfusion Injury in Rat.

The name of the Hospital in the published article is incorrect. "The First People's Hospital of Taizhou" should be "Taizhou People's Hospital".

Protective Effect of Mitogen- and Stress-Activated Protein Kinase on the Rats with Focal Ischemia-Reperfusion Injury.

Mitogen- and stress-activated protein kinase (MSK) is a recently identified nuclear cAMP-regulated enhancer B (CREB) and histone H3 kinase that responds to both mitogen- and stress-activated protein kinases. This study was designed to investigate the protective effect of MSK on the rats with focal ischemia-reperfusion injury. The rat model was established by inserting thread into the middle cerebral artery. The protein expression was measured by immunoblotting. The localization of MSK was measured by immunofluorescence assay. Highly-differentiated pheochromocytoma 12 (PC12) is used as a sympathetic neuron-like cell line and treated with glutamate to induce neurotoxicity. MSK was knocked down and overexpressed by siRNA and MSK over-expressing vector, respectively. The cell viability was measured by cell counting kit (CCK-8) assay. The coronal sections were isolated and stained with 2, 3, 5-triphenyltetrazolium chloride (TTC) to determine infarct volume. Finally, astrocytes were separated from cerebral cortexes of normal rats to analyze the effects of MSK on inflammatory response. In the rats with focal ischemia-reperfusion injury, the expression of MSK was reduced, reaching the lowest level at 3d after ischemia-reperfusion, and then recovered gradually. MSK was found mainly localized in neurons and astrocytes. The expression levels of caspase-3, caspase-8, caspase-9, and INOS showed the opposite trend with respect to MSK. Further analysis showed that overexpression of MSK exerted a protective effect on glutamate-induced neurotoxicity through inhibiting apoptosis of PC12 cells, as well as decreased the infarct size in rat with focal ischemia-reperfusion injury. On the contrary, knockdown of MSK showed opposite results. Finally, MSK suppressed LPS-induced inflammatory response by decreasing the expression of inducible nitric oxide synthase (INOS) and increasing the expression of interleukin-10 (IL-10) in astrocytes from cerebral cortexes of normal rats. In conclusion, MSK exerted a protective effect on rat with focal ischemia-reperfusion injury through its anti-apoptotic effect on neurons and anti-inflammatory effect on astrocytes.

Protective effects of Ginkgo Terpene Lactones Meglumine Injection on focal cerebral ischemia in rats

To investigate the protective effects of ginkgo diterpene lactone meglumine injection (GDLMI) on cerebral focal ischemia reperfusion injury induced by middle cerebral artery occlusion (MCAO) in rats, and explore its possible mechanism. One hundred and forty male SD rats were randomly divided into sham operation group, model group, ginkgo biloba extract injection (Ginaton, 1.0 mL•kg⁻¹) group, nimodipine (0.4 mg•kg⁻¹) group, and GDLMI (5.2, 2.6, 1.3 mg•kg⁻¹) groups; All of rats received corresponding drugs by tail vein injection 4 days before operation (normal saline in model group and sham operation group). Except the sham operation group, the cerebral ischemic stroke model was established by MCAO method in right brain of the other rats. After 3 h of ischemia, all the animals received intravenous administration again. The neurobehavioral scores of rats after ischemia-reperfusion were evaluated and the infarct rate of brain tissue was observed by TTC staining. The super oxide dismutase (SOD), glutathione (GSH), malondialdehyde (MDA) and lactic acid (LA) contents in brain tissue homogenate and the concentration of Ca2+, glutamate (Glu) and aspartate (Asp), creatine phosphate kinase (CK-BB) and lactate dehydrogenase (LDH) content changes in cerebrospinal fluid were measured. As compared with the sham operation group, the cerebral infarction rate was increased significantly in the model group; the content of MDA and LA in the homogenate of brain tissue was increased, and the content of GSH and SOD was decreased; in cerebrospinal fluid, Ca2+ concentration was decreased, and the content of Glu and Asp, CK-BB and LDH increased significantly. As compared with the model group, the high and medium dose GDLMI groups can significantly reduce the cerebral infarction rate and improve the symptoms of neurological impairment; increase SOD and GSH activity, reduce MDA and LA content in serum; increase Ca2+ concentration in cerebrospinal fluid and decrease the content of neurotransmitter Glu and Asp as well as CK-BB and LDH. GDLMI could obviously improve neurologic impairment in model rats, and the mechanism may be related to recovering the blood brain barrier, scavenging free radicals, decreasing free Ca2+ inflow into the cells and the content of excitatory amino acid in cerebrospinal fluid to improve its protective effect on cerebral ischemia.

Effect of sevoflurane on the ATPase activity of hippocampal neurons in a rat model of cerebral ischemia-reperfusion injury via the cAMP-PKA signaling pathway

We aim to investigate the effects of sevoflurane on the ATPase activity of the hippocampal neurons in rats with cerebral ischemia-reperfusion injury (IRI) via the cyclic adenosine monophosphate (cAMP) and protein kinase A (PKA) signaling pathway. Sixty rats were assigned into the normal, model and sevoflurane groups (n = 20, the latter two groups were established as focal cerebral IRI models). The ATPase activity was detected using an ultramicro Na (+)-K (+)-ATP enzyme kit. Immunohistochemical staining was used to detect the positive protein expression of cAMP and PKA. The hippocampal neurons were assigned to the normal, IRI, IRI + sevoflurane, IRI + forskolin, IRI + H89 and IRI + sevoflurane + H89 groups. qRT-PCR and Western blotting were performed for the expressions of cAMP, PKA, cAMP-responsive element-binding protein (CREB) and brain derived neurotrophic factor (BDNF). The normal and sevoflurane groups exhibited a greater positive protein expression of cAMP and PKA than the model group. Compared with the normal group, the expressions of cAMP, PKA, CREB and BDNF all reduced in the IRI, model and IRI + H89 groups. The sevoflurane group showed higher cAMP, PKA, CREB and BDNF expressions than the model group. Compared with the IRI group, ATPase activity and expressions of cAMP, PKA, CREB and BDNF all increased in the normal, IRI + sevoflurane and IRI + forskolin groups but decreased in the IRI + H89 group. It suggests that sevoflurane could enhance ATPase activity in hippocampal neurons of cerebral IRI rats through activating cAMP-PKA signaling pathway.

Transient Middle Cerebral Artery Occlusion Model of Neonatal Stroke in P10 Rats.

A number of animal models have been used to study hypoxic-ischemic injury, traumatic injury, global hypoxia, or permanent ischemia in both the immature and mature brain. Stroke occurs commonly in the perinatal period in humans, and transient ischemia-reperfusion is the most common form of stroke in neonates. The reperfusion phase is a critical component of injury progression, which occurs over a period of days to weeks, and of the endogenous response to injury. This postnatal day 10 (p10) rat model of transient middle cerebral artery occlusion (tMCAO) creates a unilateral, non-hemorrhagic focal ischemia-reperfusion injury that can be utilized to study the mechanisms of focal injury and repair in the full-term-equivalent brain. The injury pattern that is produced by tMCAO is consistent and highly reproducible and can be confirmed with MRI or histological analyses. The severity of injury can be manipulated through changes in occlusion time and other methods that will be discussed.

Transient Middle Cerebral Artery Occlusion Model of Neonatal Stroke in P10 Rats

A number of animal models have been used to study hypoxic-ischemic injury, traumatic injury, global hypoxia, or permanent ischemia in both the immature and mature brain. Stroke occurs commonly in the perinatal period in humans, and transient ischemia-reperfusion is the most common form of stroke in neonates. The reperfusion phase is a critical component of injury progression, which occurs over a period of days to weeks, and of the endogenous response to injury. This postnatal day 10 (p10) rat model of transient middle cerebral artery occlusion (tMCAO) creates a unilateral, non-hemorrhagic focal ischemia-reperfusion injury that can be utilized to study the mechanisms of focal injury and repair in the full-term-equivalent brain. The injury pattern that is produced by tMCAO is consistent and highly reproducible and can be confirmed with MRI or histological analyses. The severity of injury can be manipulated through changes in occlusion time and other methods that will be discussed.

Effect of isoflurane preconditioning on autophagy during focal cerebral ischemia-reperfusion injury in rats

Objective To evaluate the effect of isoflurane preconditioning on autophagy during focal cerebral ischemia-reperfusion(I/R)injury in rats. Methods Thirty-six healthy male Sprague-Dawley rats, weighing 250-280 g, aged 7-8 weeks, were divided into 3 groups(n=12 each)using a random number table: sham operation group(group S), cerebral I/R group(group I/R)and isoflurane preconditioning group(group IP). Focal cerebral I/R was induced by 2 h middle cerebral artery occlusion followed by 24 reperfusion.Group IP inhaled 1.5% isoflurane for 1 h per day for 5 consecutive days, the other two groups only inhaled 30% oxygen, and focal cerebral I/R was induced at 24 h after the last inhalation.At 24 h of reperfusion, neurologic deficit was assessed and scored, the rats were then sacrificed, and brains were removed for determination of cerebral infarct size(using triphenyl tetrazolium chloride staining)and expression of microtubule-associated protein 1 light chain 3-Ⅱ(LC3-Ⅱ)and Beclin-1(by Western blot). Results Compared with group S, the neurologic deficit scores and cerebral infarct size were significantly increased, and the expression of hippocampal LC3-Ⅱ and Beclin-1 was significantly up-regulated in I/R and IP groups(P<0.05). Compared with group I/R, the neurologic deficit scores and cerebral infarct size were significantly decreased, and the expression of hippocampal LC3-Ⅱ and Beclin-1 was significantly up-regulated in group IP(P<0.05). Conclusion The mechanism by which isoflurane preconditioning ameliorates focal cerebral I/R injury is related to enhancement of autophagy in the rats. Key words: Isoflurane; Ischemic preconditioning; Brain; Reperfusion injury; Autophagy

Curcumin protects against stroke and increases levels of Notch intracellular domain

Objectives: To investigate whether curcumin regulates Notch signaling to cause neuroprotection and neurogenesis after focal ischemia reperfusion injury.Method: Focal ischemia reperfusion injury was modeled in rats by occluding the middle cerebral artery. These animals were given either curcumin (300 mg/kg) or corn oil (vehicle) by intraperitoneal injection starting 1 h after stroke and continuing for 7 d. In parallel, sham-operated control animals received vehicle. All animals were killed on day 12. The different treatment groups were compared in terms of neurobehavioral deficits, BrdU incorporation, and levels of doublecortin (DCX) and Notch intracellular domain (NICD) using immunohistochemistry, immunofluorescence and Western blotting.Results: Animals treated with curcumin showed significantly smaller neurobehavioral deficits than vehicle-treated animals after 3, 7, and 12 d of reperfusion (all p < 0.05). Tissue sections from curcumin-treated animals contained significantly greater numbers of BrdU-positive cells (p < 0.05) and BrdU/DCX-positive cells (p < 0.01), as well as significantly higher NICD levels (p < 0.01).Conclusion: Curcumin may protect from focal cerebral ischemia reperfusion injury as well as stimulate neurogenesis by activating the Notch signaling pathway.

The expressions of Caspase-9 and heat-shock protein-90 after focal cerebral ischemia-reperfusion injury in rats

Objective To investigate the expression of Caspase-9 and heat-shock protein-90 (HSP 90) in rats after focal cerebral ischemia-reperfusion injury. Methods The male SD rats (200-250 g) were divided into three groups by the random number table: normal group, sham group and cerebral ischemia-reperfusion (CIR) group. Each group was sorted into four subgroups including group 6 h, group 24 h, group 48 h and group 72 h according to the reperfusion time. Suture-occluded method was adopted to prepare focal cerebral ischemia-reperfusion(CIR) injury in rat model. Enzyme-linked immunosorbent assay (ELISA) method was used to detect the variations of Caspase-9 and HSP-90 expression in rats. Results The changes in Caspase-9 and HSP 90 expression in the brain cells were observed by ELISA method. The expression of Caspase-9 and HSP-90 was weakly expressed in sham group, and was at peak in CIR group within 24 h-48 h, then began to decline at 72 h after the reperfusion time. The differences in the expression of caspase-9 and HSP-70 between sham group and normal group were not statistically significant. Conclusions Apoptotic cells gradually increase along with reperfusion time and reach the peak at 48 h after cerebral ischemia-reperfusion. In ischemia half dark stripe, the expression of Caspase-9 and HSP 90 is increased in neuronal cells after cerebral ischemia-reperfusion, and the positive cells number is at peak at 48 h after cerebral ischemia-reperfusion. Apoptosis of neuronal cells after cerebral ischemia and reperfusion is a dynamic evolutionary process. The expression of Caspase-9 and HSP 90 in nerve cells plays an important role in regulating cell apoptosis. Key words: Reperfusion injury; Caspase-9; Heat-shock proteins

Effect of resolvin D1 on focal cerebral ischemia-reperfusion injury in rats

Objective To evaluate the effect of resolvin D1 on focal cerebral ischemia-reperfusion (I/R) injury in rats. Methods One hundred and twenty adult male Sprague-Dawley rats, aged 7 weeks, weighing 260-280 g, were randomly divided into 5 groups (n=24 each) using a random number table: sham operation group (group S) , group I/R, low-dose resolvin D1 group (group LRD) , medium-dose resolvin D1 group (group MRD) , and high-dose resolvin D1 group (group HRD) . Focal cerebral I/R was induced by right middle cerebral artery occlusion using a nylon thread inserted into internal carotid artery and advanced cranially until resistance was met.The occlusion was maintained for 2 h followed by 24 h reperfusion.In LRD, MRD and HRD groups, 0.03, 0.10, 0.30 nmol resolvin D1 5 μl was injected into the lateral cerebral ventricle at the beginning of reperfusion, respectively.Neurological deficits were evaluated at 24 h of reperfusion and scored.The rats were then sacrificed, and their brains were removed for determination of infarct volume (by TTC staining) , cerebral water content, Evans blue content and expression of matrix metalloproteinase-9 (MMP-9) in the ischemic cortex. Results Compared with group S, the neurological deficit scores, cerebral infarct volume, and cerebral water and Evans blue content were significantly increased, and the expression of MMP-9 was up-regulated in the other 4 groups.Compared with group I/R, the neurological deficit scores, cerebral infarct volume, and cerebral water and Evans blue content were significantly decreased, and the expression of MMP-9 was down-regulated in group MRD and group HRD, and no significant change was found in the parameters mentioned above in group LRD. Conclusion Resolvin D1 can attenuate focal cerebral I/R injury in rats, and down-regulation of MMP-9 expression and decrease in permeability of blood-brain barrier may be involved in the mechanism. Key words: Docosahexaenoic acids; Reperfusion injury; Cerebral

Protective effect of aspirin against the brain ischemia reperfusion injury on rats and the related mecha-nism

Objective To investigate the effect of aspirin on the focal brain ischemia reperfusion injury(IRI)and the related mechanism. Methods Forty Sprague-Dawley male rats were randomly divided into three groups: control group(CTL) given middle cerebral artery occlusion (MCAO)and saline pretreatment for 7 days as placebo(n= 16); aspirin group(ASA)given aspirin via gastric gavage at a dose of 30 mg/(kg·d) for 7 days(n= 16); and sham group(Sham) for comparison(n= 8).Middle cerebral artery was occluded by thread for 90 min, followed by reperfusion. The neurological outcomes including edema index, infarc size and neurological deficit scores were evaluated 24 h after MCAO.The levels of interleukin(IL)-1β, IL-6 and malonaldehyde(MDA), and activity of superoxide dismutase(SOD)in the brain tissue were assessed according to the corresponding kits. Results As compared with CTL group, aspirin significantly reduced the edema index, infarc size and neurological deficit scores at 24 h after MCAO(P< 0.01). Also, aspirin decreased the tissue levels of IL-1β[(78.03±9.28) pg/mg vs.(439.10±71.80) pg/mg, P< 0.01], IL-6 [(86.35±10.19) pg/mg vs.(486.00±56.90) pg/mg, P< 0.01]and MDA[(1.74±0.31) nmol/mg protein vs.(3.96±0.68) nmol/mg protein,P< 0.05], and enhanced the activity of SOD[(274.26± 31.64) U/mg protein vs.(195.35±26.31) U/mg protein,P<0.05]compared to CTL group. Conclusion Aspirin can protect against focal brain IRI partly through the mechanism of attenuating oxidative stress and inhibiting the over-expression of pro-inflammatory cytokines. Key words: Aspirin; Brain ischemia; Reperfusion injury; Inflammatory response; Oxidative stress

Effect of remote limb ischemic postconditioning combined with electro-acupuncture postconditioning on focal cerebral ischemia-reperfusion injury in rats

Objective To evaluate the effect of remote limb ischemic postconditioning(RLIP)combined with electro-acupuncture postconditioning(EAP)on focal cerebral ischemia-reperfusion(I/R)injury in rats. Methods Seventy male Sprague-Dawley rats, weighing 220-250 g, were randomly assigned into 5 groups(n=14 each)using a random number table: sham operation group(group S), group I/R, RLIP group, EAP group and RLIP combined with EAP group(group RLIP+ EAP). Focal cerebral I/R was induced by middle cerebral artery occlusion(MCAO). MCAO was maintained for 120 min.The animals were subjected to 3 cycles of 15 min ischemia of bilateral hind limbs followed by 30 s reperfusion starting from onset of reperfusion.Dazhui and Baihui acupoints were stimulated with electric stimulator(frequency 15 Hz/2 Hz, intensity 1 mA)for 30 min starting from onset of reperfusion.Neurological deficit scores(NDSs)were evaluated at 24 h of reperfusion.The animals were then sacrificed and brains were removed to measure the infarct size and for microscopic examination of pathological changes in hippocampal CA1 region.The number of survival neurons was counted.The apoptosis in neurons was determined by TUNEL.Apoptosis index was calculated. Results Compared with group S, the NDSs, percentage of cerebral infarct size and AI were significantly increased, and the number of survival neurons was decreased in the other four groups.Compared with group I/R, the NDSs, percentage of cerebral infarct size and AI were significantly decreased, and the number of survival neurons was increased in EAP, RLIP and RLIP+ EAP groups.Compared with RLIP and EAP groups, the NDSs, percentage of cerebral infarct size and AI were significantly decreased, and the number of survival neurons was increased in group RLIP+ EAP. Conclusion The combination of RLIP and EAP provides better efficacy than either alone in attenuating focal cerebral I/R injury in rats. Key words: Electric stimulation therapy; Brain; Reperfusion injury; Extremities; Ischemic postconditioning

Long Non Coding RNA-UCA1 Contributes to Cardiomyocyte Apoptosis by Suppression of p27 Expression

Background/Aims: Urothelial carcinoma-associated 1 (UCA1) is a recently identified long non coding RNA (lncRNA). However, few studies have explored its role in cardiomyocytes after focal cardiac ischemia reperfusion injury (CIR). Methods: Rat CIR models were established using ligation of the Lower Anterior Descending artery (LAD). Cell apoptosis and reactive oxygen species (ROS) production in cardiac tissues were explored using immunohistochemistry and DHE staining. lncRNA expression patterns were detected using microarray and validated by qPCR. Cell viability and apoptosis were examined using MTT assay and flow cytometry. Results: CIR significantly induced cell apoptosis and ROS production in the rat model. The results of microarray demonstrated the reduced expression of UCA1, which was validated by qPCR. Follow-up experiments showed that UCA1 was involved in H₂O₂-induced cell apoptosis. We further showed that UCA1 negatively correlated with the expression of p27. Moreover, overexpression of p27 could induce primary cardiomyocyte apoptosis. Conclusions: Reduction of UCA1 levels plays a pro-apoptotic role in primary cardiomyocytes partially through stimulation of p27 protein expression. These results are in agreement with the observed levels of UCA1, p27 and apoptosis after cardiac I/R injury, suggesting that UCA1 might have an important role during I/R injury.

Effect of propofol with edaravone on the expression of glial fibrillary acidic protein after ischemia-reperfusion injury in rats

Objective To investigate the effect of propofol with edaravone on the expression of glial fibrillary acidic protein (GFAP) after focal brain ischemia-reperfusion injury in rats.Methods The middle cerebral artery (MCA) focal cerebral ischemia-reperfusion rat models were established by thread occlusion method.Rats were randomly divided into focal cerebral ischemia group (I/R),Edaravone-treated group (ED) and Edaravone with Propofol-treated group (PE).After ischemia for 2 h,four subgroups were set up according to the reperfusion time (4,12,24,and 48 h).After measurement of the score of neurological deficits,the infarct volume of brain ischemic damage was estimated by the tovanto transit commission (TTC) staining.Strept avidin-biotin complex (SABC) method was used to detect the expression of brain tissue GFAP.Results The infarction volume was detected at 4 h after focal brain ischemia-reperfusion.Infarction volume became larger as time prolonging.GFAP expression of brain tissue was increased in ED and PE groups [(45.10 ±2.93) vs.(43.30 ±2.71) vs.(23.30 ±2.71)].As compared with control group,the infarction volumes were significantly deflated in ED and PE groups [(16.50 ±0.67)％ vs.(16.80 ± 0.76) ％ vs.(20.50 ± 0.78) ％] (P ＜ 0.05),and the scores of neurological deficits were also decreased [(2.75 ±0.61) vs.(1.77 ±0.54) vs.(1.69 ±0.63)] (P＜0.05).Conclusion Edaravone can increase the expression of GFAP and cerebral infarction volume,and attenuate neurologic function deficits after cerebral ischemia-reperfusion in rats. Key words: Edaravone; Propofol; Cerebral ischemia; Glial fibrillary acidic protein

A combination of four active compounds alleviates cerebral ischemia-reperfusion injury in correlation with inhibition of autophagy and modulation of AMPK/mTOR and JNK pathways.

SMXZF is a combination of Rb1, Rg1, schizandrin, and DT-13 (6:9:5:4) derived from Sheng-mai San, a widely used Chinese traditional medicine for the treatment of cardiovascular and cerebral diseases. The present study explores the inhibitory effects and signaling pathways of SMXZF on autophagy induced by cerebral ischemia-reperfusion injury. Male C57BL/6 mice were subjected to ischemia-reperfusion insult by right middle cerebral artery occlusion (MCAO) for 1 hr with subsequent 24 hr reperfusion. Three doses of SMXZF (4.5, 9, and 18 mg/kg) were administered intraperitoneally (i.p.) after ischemia for 1 hr. An autophagic inhibitor, 3-methyladenine (3-MA; 300 μg/kg), was administered i.p. 20 min before ischemia as a positive drug. We found that SMXZF significantly increased cerebral blood flow and reduced the infarct volume, brain water content, and the neurological deficits in a dose-dependent manner. Similar to the positive control, SMXZF at 18 mg/kg also significantly inhibited autophagosome formation. Immunofluorescence staining and Western blotting demonstrated that SMXZF could significantly decrease the expression levels of beclin1 and microtubule-associated protein 1 light chain 3. SMXZF also remarkably inhibited the phosphorylation of adenosine monophosphate-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR) as well as the expression of c-Jun N-terminal kinase (JNK) and its phosphorylation induced by 24 hr reperfusion. Finally, we demonstrated that the optimal administration time of SMXZF was at the early period of reperfusion. This study reveals that SMXZF displays neuroprotective effect against focal ischemia-reperfusion injury, possibly associated with autophagy inactivation through AMPK/mTOR and JNK pathways.

Effect of butylphthalide and sodium chloride injection postconditioning on focal cerebral ischemia-reperfusion injury and endoplasmic reticulum stress in rats

Objective To investigate the effect of butylphthalide and sodium chloride injection postconditioning on focal cerebral ischemia-reperfusion (I/R) injury and endoplasmic reticulum stress in rats.Methods Thirty-six male SPF Sprague-Dawley rats,aged 2-3 months,weighing 260-280 g,were randomly divided into 3 groups (n =12 each):sham operation group (group S),focal cerebral I/R group (group I/R) and butylphthalide and sodium chloride injection postconditioning group (group Buty).The animals were anesthetized with intraperitoneal 10 ％ chloral hydrate 300 mg/kg.Focal cerebral I/R was induced by occluding right middle cerebral artery for 2 h followed by 24 h reperfusion in I/R and Buty groups.Butylphthalide and sodium chloride injection 2.5 mg/kg was injected via the tail vein immediately after onset of reperfusion in Buty group,while the equal volume of normal saline was injected in I/R group.Neurological deficits were assessed and scored at 24 h of reperfusion,and then the brain was isolated for detection of neuronal apoptosis (by TUNEL) and the expression of glucose-regulated protein 78 (GRP78) and caspase-12 in ischemic cerebral cortex (by immunohistochemistry) in brain tissues.Apoptosis index was calculated.Results Compared with group S,the neurological deficit scores and apoptosis index were significantly increased,and the expression of GRP78 and caspase-12 was up-regulated in I/R and Buty groups (P ＜ 0.05 or 0.01).Compared with group I/R,the neurological deficit scores and apoptosis index were significantly decreased,the expression of GRP78 was up-regulated,and the expression of caspase-12 was down-regulated in group Buty (P ＜ 0.05).Conclusion Butylphthalide and sodium chloride injection postconditioning can reduce focal cerebral I/R injury in rats,and inhibition of endoplasmic reticulum stressmediated cell apoptosis is involved in the mechanism. Key words: Benzofurans; Reperfusion injury; Brain; Endoplasmic reticulum ; Stress; Ischemic postconditioning

Abstract 9446: Periodic Acceleration (pGz) Preserves Heart Rate Variability After Cardiac Arrest

Heart Rate Variability (HRV) and lack thereof is important in predicting neurological outcome after brain injury and cardiac arrest (CA). The post CA period has decreased HRV compared to pre-arrest, and interventions such hypothermia may preserve HRV. Periodic acceleration (pGz) the sinusoidal head to foot motion of the supine body with a motion platform increases endothelial derived NO (eNO) and neuronal nitric oxide (nNOS) in heart via pulsatile shear stress, and preconditions from global and focal ischemia reperfusion injury (I/R). NO has a facilitator role on vagal chronotropism and inhibition of nNOS reduces HRV. CA is a model of whole body I/R. This study tests whether pGz applied prior to whole body I/R preserves HRV in a pig model of CA. Fourteen male swine (40-50lbs) were anesthetized, intubated and instrumented to measure EKG and hemodynamics. They were placed on a motion platform and randomized to 1 hr of pGz (180 cpm and Gz ± 0.4) or none control (C). VF was electrically induced and unsupported for 8 min, followed by chest compression and defibrillation until return of spontaneous circulation (ROSC) or 10 min. Short term HRV (excluding ectopic beats) was measured including; time domain; SDNN (standard deviation of normal to normal intervals), RMSSD (square root of the mean squared differences of successive normal to normal intervals) and frequency domain, at baseline (BL1), after pGz or C (BL2) and 30, to 180 mins after ROSC (ROSC30, 60,120,180 ). All animals had ROSC after a median of 4 defibrillation attempts. There were no differences between groups in defibrillation attempts, time to ROSC, arterial blood gases or hemodynamics over time. pGz animals had less hemodynamically significant arrhythmias in the first 30 mins ROSC; C (35) vs pGz (7) (p&lt; 0.05) Data mean ±SEM * p &lt; 0.05 C vs pGz. pGz applied prior to I/R in addition to being cardioprotective preserves HRV and is a novel non invasive method to preserve autonomic nervous system output and precondition the myocardium.