Imaging predictors of clinical outcomes after endovascular treatment in MRI-selected patients with acute basilar artery occlusion.

PURPOSE: We aimed to investigate the impact of baseline infarct area and collateral status (CS), which are imaging predictors of clinical outcome following stroke, after endovascular treatment (EVT) in MRI-selected patients with acute basilar artery occlusion (BAO). METHODS: Patients with acute BAO who underwent EVT within 24 h after stroke from December 2013 to February 2021 were included in this retrospective, multicenter, observational study. The baseline infarct area was evaluated by the posterior circulation of Acute Stroke Prognosis Early Computed Tomography Score (pc-ASPECTS) using diffuse-weighted imaging (DWI), and CS was assessed by measuring the computed tomography angiography of the basilar artery (BATMAN) score and the posterior circulation collateral score (PC-CS) using magnetic resonance angiography (MRA). A Good outcome was defined as a modified Rankin scale score ≤ 3 at 3 months. For each imaging predictor, a multivariate logistic regression analysis was performed to evaluate its impact on good outcomes. RESULTS: A total of 86 patients were analyzed, and 37 (43.0%) had a good outcome. The latter showed significantly higher pc-ASPECTS than those without good outcomes. In multivariate analyses, a pc-ASPECTS ≥ 7 was significantly associated with good outcomes (OR, 2.98 [95% CI, 1.10-8.13], P = 0.032), while PC-CS ≥ 4 (OR, 2.49 [95% CI, 0.92-6.74], P = 0.073) and BATMAN score ≥ 5 (OR, 1.51 [95% CI, 0.58-3.98], P = 0.401) were not. CONCLUSIONS: In MRI-selected patients with acute BAO, pc-ASPECTS on DWI was an independent predictor of clinical outcomes after EVT, while the MRA-based CS assessments were not.

Shenfu Administration Improves Cardiac Fibrosis in Rats With Myocardial Ischemia-Reperfusion Through Adenosine A2a Receptor Activation.

OBJECTIVE: Shenfu injection (SFI) is commonly used for cardiac dysfunction in China. Adenosine receptors have been reported to exert anti-fibrosis effects. The intent of this study was to evaluate that SFI attenuates cardiac fibrosis through activating of adenosine A2a receptor (A2aR) in rats with myocardial ischemia-reperfusion (MI/R). METHODS: Sprague Dawley male rats were randomly divided into five groups, nine rats in each group. Injections in all rat groups were carried out prior to reperfusion, and in the sham and MI/R groups, only vehicle was injected. Injections in the remaining group were as follows: 5 mL/kg in the SFI group; 15 mg/kg nicorandil in the A2R agonist group; and 5 mL/kg SFI plus 5 mg/kg MSX-3 in the SFI + A2aR antagonist group. Changes in cyclic adenosine monophosphate (cAMP) and the development of myocardial infarction and cardiac fibrosis were documented among the groups. Additionally, the levels of A2aR, collagen Ⅰ, collagen Ⅲ, fibronectin, and matrix metalloproteinase-9 (MMP-9) were measured. RESULTS: Following injection with SFI or nicorandil, the cAMP concentration, infarct area, and cardiac fibrosis induced by MI/R injury were significantly decreased (p < 0.05). Additionally, the levels of collagen Ⅰ, collagen Ⅲ, fibronectin, and MMP-9 were clearly suppressed by SFI or nicorandil when compared with the MI/R group (p<0.01). However, the protective effects of SFI were counteracted by MSX-3. A negative correlation between A2aR and collagen I and collagen III was found (p = 0.00). CONCLUSION: SFI activated the A2aR to reduce myocardial fibrosis caused by MI/R injury, which provided an underlying mechanism of action of SFI.

Adoption of computerized tomography perfusion imaging in the diagnosis of acute cerebral infarct under optimized deconvolution algorithm.

OBJECTIVES: To explore the significance of the hemodynamic parameters of Computerized Tomography Perfusion Imaging (CTPI) under the deconvolution optimization algorithm for the diagnosis and treatment of patients with acute cerebral infarct (ACI). METHODS: A hundred and ten patients with ACI from December 2018 to September 2019 were selected for research, and CTPI was performed before and after Edaravone injection treatment. Then, the CTPI deconvolution algorithm based on the weighted adaptive (WA) total variation (TV) (WA-TV) optimization was constructed, which was compared with tensor total variation (TTV) and Motion-adaptive sparse parity (MASP). Brain Perfusion 4.0 was applied to obtain the relative time to peak (rTTP), the relative transit time of mean (rMTT), relative cerebral blood volume (rCBV), and relative cerebral blood flow (rCBF) of the core infarction area (CIA) and penumbra ischemic (PI). RESULTS: In four parameters of rTTP, rMTT, rCBV, and CBF, the peak signal to noise ratio (PSNR) of the WA-TV algorithm was higher than the MSAP and TTV algorithms, while the Mean Square Error (MSE) and Mean Absolute Error (MAE) were lower than MSAP and TTV algorithms (P<0.05); the parameters of rCBV (71.56±9.87), rCBF (43.17±7.06) of the CIA before treatment were higher than PI (23.66±7.22; 18.37±3.99), rMTT (124.83±9.73) and rTTP (122.57±7.41) were lower than the PI (183.17±10.16); 150.74±9.74) (P<0.05). After treatment, the rCBV and rCBF of PI were higher than before treatment, and rMTT and rTTP were lower than before treatment (P<0.05), and there was no obvious difference in rCBV, rCBF, rMTT, and rTTP before and after treatment in the CIA (P>0.05). CONCLUSION: Compared with TTV and MASP, the WA-TV algorithm performs better in noise reduction and artifact reduction. The CTPI parameters of rCBV, rCBF, rMTT, and rTTP are all important indications for the diagnosis of PI and ACI.

Effects of Shenfu injection on myocardial adenosine receptors in rats with myocardial ischemia-reperfusion postconditioning.

OBJECTIVE: Shenfu injection (SFI) has been reported to have a protection against myocardial ischemia-reperfusion (MI/R) injury. However, the changes of adenosine receptors in MI/R postconditioning when pretreated with SFI are unclear. METHODS: Forty-five rats were randomly divided into sham group (sham), MI/R postconditioning group (MI/R-post), low-dose SFI group (1 mL/kg), middle-dose SFI group (2.5 mL/kg), and high-dose SFI group (5 mL/kg). In SFI groups, SFI was intravenously injected before reperfusion, and rats were treated with ischemic postconditioning after ischemia for 30 min. After 24 h of reperfusion, the levels of Ca2+ and cAMP in blood platelets were analyzed. Myocardial infarct volume and myocardial pathology were observed. The levels of adenosine receptor subtypes A1, A2b, and A3 in myocardium were analyzed using immunohistochemistry and Western blot. The oxidative stress-related indicators were also observed. RESULTS: Compared with the MI/R-post group, SFI ameliorated the MI/R injury by decreasing the myocardial infarct area, oxidative stress, and concentration of Ca2+ and cAMP (p < 0.01). Pretreatment with SFI enhanced the expression of adenosine receptors A1 and A2b in a dose manner compared with the MI/R-post group. In contrast, the levels of adenosine receptor A3 were increased after MI/R postconditioning compared with the sham group, and its expression continued to increase with the increase of SFI. Furthermore, the oxidative stress reduced with the concentrations of SFI. CONCLUSION: These results demonstrated that pretreatment with SFI might regulate the expression of adenosine receptors to improve the MI/R postconditioning.

The correlation of the peripheral blood NT-proBNP and NF-κB expression levels with the myocardial infarct area and the post-treatment no-reflow in acute myocardial infarction patients.

OBJECTIVE: To explore the correlation of the peripheral blood NT-proBNP and NF-κB p65 expression levels in the peripheral blood with the myocardial infarct areas on the admission and post-treatment no-reflow of acute myocardial infarction patients. METHODS: A total of 124 acute myocardial infarction patients treated in our hospital were placed in an acute myocardial infarction group, 115 patients with stable coronary heart disease were placed in a coronary heart disease group, and 121 healthy people undergoing routine physical examinations were placed in a healthy examination group. After the treatment, the myocardial infarction patients were divided into grade I, grade II, grade III, and grade IV groups according to their Killip heart function classifications. The patients were divided into reflow (thrombolysis in myocardial infarction (TIMI) > grade 2) and no-reflow (TIMI ≤ grade 2) groups according to their flow grades, and into single branch, double branch, and multi-branch groups according to each patient's number of diseased coronary vessels. The Wagner scale scores were used to estimate the infarct areas. All the patients were divided into small area, medium area, and large area groups according to the score results or into good prognosis and poor prognosis groups according to the presence or absence of complications. The amino-terminal pro-brain natriuretic peptide (NT-proBNP) and the nuclear factor-kappa B p65 (NF-κB p65) expression levels in the peripheral blood among the groups were compared. RESULTS: The NT-proBNP and NF-κB p65 expression levels in the peripheral blood were significantly lower in the physical examination and coronary heart disease groups than they were in the acute myocardial infarction group (P<0.001) and were the lowest in the physical examination group (P<0.05). The expression levels were the lowest in the grade I group according to their Killip heart function classification (P<0.001) and increased gradually in each of the grade I to IV groups (all P<0.001). The expression levels were lowest in the single branch group and highest in the multi-branch group (P<0.001). The expression levels were lower in the no-reflow group than they were in the reflow group (P<0.001). The expression levels increased in the large area group compared with the small area and medium area groups (P<0.001). The expression levels were higher in the poor prognosis group than in the good prognosis group (P<0.001). CONCLUSION: Patients with high peripheral blood NT-proBNP and NF-κB expression levels had increased myocardial infarct areas. The peripheral blood NT-proBNP and NF-κB levels increased in the patients with post-treatment reflow. Therefore, the NT-proBNP and NF-κB expression levels can be used as important indicators for predicting the severity and prognoses of acute myocardial infarction patients.

ΜicroRNA-122 protects against ischemic stroke by targeting Maf1.

The protection of brain tissue against damage and the reduction of infarct size is crucial for improving patient prognosis following ischemic stroke. Therefore, the present study aimed to investigate the regulatory effect of microRNA (miR)-122 and its target gene repressor of RNA polymerase III transcription MAF1 homolog (Maf1) on the infarct area in ischemic stroke. Reverse transcription-quantitative PCR (RT-qPCR) was performed to determine miR-122 expression levels in an ischemic stroke [middle cerebral artery occlusion (MCAO)] mouse model. Nissl staining was conducted to measure the infarct area of the MCAO mouse model. Moreover, RT-qPCR was performed to investigate the relationship between the expression of Maf1 and miR-122 in the MCAO mouse model. Dual-luciferase reporter assay in vitro and miR-122 mimic or inhibitor treatment in vivo were conducted to verify that miR-122 targeted and inhibited Maf1 expression. The results suggested that miR-122 was upregulated in the brain tissue of MCAO model mice. miR-122 overexpression effectively reduced the size of the infarct area in comparison with a control and miR-122 knockdown in brain tissue resulted in the opposite effect. Moreover, Maf1 was confirmed to be a direct target of miR-122. The results of a dual-luciferase reporter assay indicated that miR-122 bound to the 3'-untranslated region of Maf1. Maf1 expression decreased after stroke model induction in comparison with that in sham animals, and Maf1 expression was negatively associated with the expression of miR-122. In addition, miR-122 knockdown increased Maf1 expression levels, whereas miR-122 overexpression decreased Maf1 expression levels in comparison with a control. In conclusion, the results suggested that miR-122 improved the outcome of acute ischemic stroke by reducing the expression of Maf1.

MSC exosome-mediated cardioprotection in ischemic mouse heart comparative proteomics of infarct and peri-infarct areas.

Mesenchymal stem cell (MSC) exosomes may limit cardiac injury, and even reverse cardiac damage in animal models of ischemia. To understand exosome-mediated improvement in cardiac function we examined the proteomic alternations in the MSC exosome-treated mice hearts subjected to left coronary artery (LCA) ligation, with particular emphasis on peri-infarct areas. At 7 days after LCA ligation, left ventricular end systolic thickness, infarct size and survival of mice were studied. Mass spectrometric analysis of infarct and peri-infarct areas was carried out. Expression of inflammatory markers (LOX-1 and NLRP3) and cell death markers (Bax, Bcl-2, Caspases 1 and 3 and GSDMD) were investigated by Western blots and immunofluorescence. Proteomic analysis of the infarct and peri-infarct areas in saline-treated hearts revealed differentially expressed proteins involved in inflammation and apoptotic cell death, while showing depletion of processes governing cell death. Exosome treatment significantly improved the proteomic profile in both infarct and peri-infarct areas, more so in the peri-infarct areas. The infarct size was smaller (9 ± 1%), and cardiac contractile function (fractional shortening) was preserved in the exosome-treated mice (28 ± 2%). Survival of exosome-treated mice was also better. White blood cell accumulation in and around the infarct area, expression of LOX-1 and NLRP3 inflammasome, and markers of cell death (cleaved Caspase-3, Caspase-1, GSDMD, Bcl-2 and Bax) were dramatically reduced by MSC exosome treatment (all p < 0.01). In cultured primary mouse cardiomyocytes, treatment with MSC exosomes essentially reversed inflammation-induced pro-apoptotic and inflammatory signals (p < 0.01). MSC exosomes exert their cardioprotective effects by suppressing inflammation and pro-apoptotic processes, particularly in the peri-infarct areas, resulting in preservation of cardiac function after LCA ligation.

Intra-arterial Stem Cell Therapy Diminishes Inflammasome Activation After Ischemic Stroke: a Possible Role of Acid Sensing Ion Channel 1a.

Studies from our lab demonstrated that 1 × 105 intra-arterial mesenchymal stem cells (IA MSCs) at 6 h following ischemic stroke are efficacious owing to its maximum homing due to elevated stromal derived factor 1 (SDF1) in the tissue. Further, IA MSCs could abate the infarct progression, improve functional outcome, and decrease expression of calcineurin by modifying neuronal Ca2+ channels following ischemic stroke. Since stroke pathology also encompasses acidosis that worsens the condition; hence, the role of acid sensing ion channels (ASICs) in this context could not be overlooked. ASIC1a being the major contributor towards acidosis triggers Ca2+ ions overload which progressively contributes towards exacerbation of neuronal injury following ischemic insult. Inflammasome involvement in ischemic stroke is well reported as activated ASIC1a increases the expression of inflammasome in a pH-dependent manner to trigger inflammatory cascade. Hence, the current study aimed to identify if IA MSCs can decrease the production of inflammasome by attenuating ASIC1a expression to render neuroprotection. Ovariectomized Sprague Dawley (SD) rats exposed to middle cerebral artery occlusion (MCAo) for 90 min were treated with phosphate-buffered saline (PBS) or 1 × 105 MSCs IA at 6 h to check for the expression of ASIC1a and inflammasome in different groups. Inhibition studies were carried out to explore the underlying mechanism. Our results demonstrate that IA MSCs improves functional outcome and oxidative stress parameters, and decreases the expression of ASIC1a and inflammasomes in the cortical brain region after ischemic stroke. This study offers a preliminary evidence of the role of IA MSCs in regulating inflammasome by modulating ASIC1a.

Dipeptidyl Peptidase-4 deficiency effectively protects the brain and neurological function in rodent after acute Hemorrhagic Stroke.

This study tested the hypothesis that abrogated dipeptidyl peptidase-4 (DPP4) activity played a crucial role on reducing stroke volume and preserving neurological function in rodent after acute hemorrhagic stroke (AHS). Animals (n=6/each group) were categorized into group 1 (sham-control of F344 rat), group 2 (sham-control of DPP4-deficiency rat), group 3 [AHS by right cerebral injection of autologous blood (100 µL) in F344 rat], group 4 (AHS + sitagliptin/600 mg/kg 3 h prior to and at 3 h then once per day after AHS) and group 5 (AHS in DPP4-deficiency rat). The results of corner test showed the neurological function was significantly improved from days 3, 7, and 14 in groups 4 and 5 than in group 3 (all p<0.001). By days 1 and 14 after AHS procedure, the circulating levels of SDF-1α and GLP-1 were significantly increased from groups 1/2 to group 5 (all p<0.001), whereas circulating DPP4 activity was significantly increased in group 3 than other groups (all p<0.001). The brain ischemic area (BIA) was highest in group 3, lowest in groups 1/2 and significantly lower in group 5 than in group 4 (all p<0.0001). The protein expressions of oxidative-stress/inflammatory/apoptotic/cell-proliferation signaling, and the cellular expressions of inflammatory/DNA-damaged biomarkers exhibited a similar pattern to BIA among the groups (all p<0.01). In conclusion, deprivation of DPP4 activity protected the brain from AHS damage and preserved neurological function.

Pinin protects astrocytes from cell death after acute ischemic stroke via maintenance of mitochondrial anti-apoptotic and bioenergetics functions.

BACKGROUND: Stroke is the second most common cause of deaths worldwide. After an ischemic stroke, the proliferated reactive astrocytes in the peri-infarct areas play a beneficial role in neuronal survival. As such, astrocytes have gradually become a target for neuroprotection in stroke. The present study assessed the hypothesis that Pinin (Pnn), originally identified as a nuclear and desmosome-associated protein and is now known to possess anti-apoptotic capacity, protects astrocytes from cell death after ischemic stroke and delineated the underlying mechanisms. METHODS: In in vivo experiments, adult male Sprague-Dawley rats (12-week old) were used to induce acute focal cerebral ischemia employing the middle cerebral artery occlusion (MCAO) method. In in vitro experiments, postnatal day 1 (P1) Sprague-Dawley rat pups were used to prepare cultures of primary astrocytes. Oxygen-glucose deprivation (OGD) and re-oxygenation (OGD/R) procedures were employed to mimic the hypoxic-ischemic condition of stroke in those astrocytes. RESULTS: We found in the peri-infarct area of the ipsilateral cortex and striatum in Sprague-Dawley rats after transient MCAO an increase in Pnn expression that correlated positively with the time-course of infarction as detected by T2-weighted imaging and triphenyltetrazolium chloride staining, augmented number of reactive astrocytes that double-labelled with Pnn as determined by immunofluorescence, and enhanced cytotoxic edema as revealed by diffusion weighted imaging; but mirrored the decreased cleaved caspase-3 as measured by western blot. In an OGD and OGD/R model using primary cultured astrocytes, treatment with Pnn siRNA doubled the chance of surviving astrocytes to manifest cell death as revealed by flow cytometry, and blunted activated ERK signaling, reduced Bcl-2 expression and augmented cleaved caspase 3 detected by western blot in the normoxia, OGD or OGD/R group. Gene-knockdown of Pnn also impeded the reversal from decline in cell viability, elevation in lactate dehydrogenase leakage and decrease in ATP production in the OGD/R group. CONCLUSION: We conclude that the endogenous Pnn participates in neuroprotection after acute ischemic stroke by preserving the viability of astrocytes that survived the ischemic challenge via maintenance of mitochondrial anti-apoptotic and bioenergetics functions.

Resveratrol mitigates the oxidative stress mediated by hypoxic-ischemic brain injury in neonatal rats via Nrf2/HO-1 pathway.

CONTEXT: Hypoxic-ischemic encephalopathy (HIE) has a high morbidity and mortality rate. Resveratrol possesses numerous biological properties including antioxidant, anti-inflammatory and neuroprotective activities. OBJECTIVE: The current experiment investigates the neuroprotective efficacy of resveratrol (RESV) against HIE by modulating Nrf2/HO-1 pathway in neonatal rats. MATERIALS AND METHODS: Seven-day-old pups (n = 48) were divided into four groups. Group-I rats receiving 2% DMSO saline (sham), group-II rats underwent unilateral carotid artery ligation and hypoxia (92% N2 and 8% O2) for 2.5 h (hypoxia-ischemia; HI), group-III and IV rats received 20 (RESV 20 + HI) or 40 mg/kg (RESV 40 + HI; group-IV) of RESV via intraperitoneal injection (ip), respectively, for 7 days prior to HI induction. RESULTS: Pre-treatment with RESV (20 or 40) markedly reduced (p < 0.01) the cerebral oedema (86.23-71.26 or 65.24%), infarct area (33.85-19.81 or 14.30%), lipid peroxidation products, inflammatory markers [IL-1ß 186-110 or 82; IL-6 255-146 or 103; TNF-α 310-204 or 137; NF-κB 205-115 or 91) p65 subunit] and significantly restored (p < 0.01) the antioxidative status by enhancing the activities of glutathione peroxidase (GPx) 5.22-6.49 or 7.78; catalase (CAT) 51-55 or 59, superoxide dismutase (SOD) 2.5-3.05 or 3.25; through marked upregulation (p < 0.01) of heme oxygenase 1 (HO-1) 0.65-0.69 or 0.73; and nuclear factor erythroid 2 related factor 2 (Nrf2) 0.73-0.86 or 0.91. DISCUSSION AND CONCLUSIONS: RESV displays its neurotherapeutic potential via upregulating the protein expression of Nrf2 and HO-1 signalling pathway and thereby attenuates oxidative stress and inflammatory response in HI-induced neonatal rats.

Whole Body Vibration Therapy after Ischemia Reduces Brain Damage in Reproductively Senescent Female Rats.

A risk of ischemic stroke increases exponentially after menopause. Even a mild-ischemic stroke can result in increased frailty. Frailty is a state of increased vulnerability to adverse outcomes, which subsequently increases risk of cerebrovascular events and severe cognitive decline, particularly after menopause. Several interventions to reduce frailty and subsequent risk of stroke and cognitive decline have been proposed in laboratory animals and patients. One of them is whole body vibration (WBV). WBV improves cerebral function and cognitive ability that deteriorates with increased frailty. The goal of the current study is to test the efficacy of WBV in reducing post-ischemic stroke frailty and brain damage in reproductively senescent female rats. Reproductively senescent Sprague-Dawley female rats were exposed to transient middle cerebral artery occlusion (tMCAO) and were randomly assigned to either WBV or no-WBV groups. Animals placed in the WBV group underwent 30 days of WBV (40 Hz) treatment performed twice daily for 15 min each session, 5 days each week. The motor functions of animals belonging to both groups were tested intermittently and at the end of the treatment period. Brains were then harvested for inflammatory markers and histopathological analysis. The results demonstrate a significant reduction in inflammatory markers and infarct volume with significant increases in brain-derived neurotrophic factor and improvement in functional activity after tMCAO in middle-aged female rats that were treated with WBV as compared to the no-WBV group. Our results may facilitate a faster translation of the WBV intervention for improved outcome after stroke, particularly among frail women.

Low Doses of G-CSF Prevent Cerebral Infarction and Maintain Muscle Strength in an Experimental Model of Global Ischemic Stroke.

BACKGROUND: Stroke is a major cause of severe and long-term disability in adult individuals. Treatment of this disease is limited by the narrow therapeutic window in which intervention is crucial. An alternative therapy for stroke could be cellular growth factors, which participate in several pathways that mediate neuronal cell death. METHODS: We evaluated the neuroprotective ability of different doses of granulocyte colonystimulating factor (G-CSF; 5, 50 and 100 µg/kg/day) in the mouse model of global cerebral ischemia induced by bilateral occlusion of the common carotid arteries for 80 minutes. The control group received vehicle (5% glucose solution) and the treated group was administered with G-CSF at two postsurgery time-points: immediately after and 24 hours after. Subsequently, muscle strength, leukocyte count, infarcted cortical area, and apoptosis/TUNEL were evaluated. RESULTS: The global ischemia promoted an impairment of the strength (16%) and a cerebral infarction (0.437±0.08 cm2) which were accompanied by apoptosis evaluated by TUNEL in control mice. In mice treated with G-CSF the strength function was maintained, the infarcted area (~70%) and apoptosis were decreased in a similar magnitude in all treated groups. Accordingly, the cytokine activities were confirmed by blood leukocyte count that was increased approximately 2-fold than that observed in the control group. CONCLUSION: The results indicate a neuroprotective effect of G-CSF, even in small doses, in mice subjected to global cerebral ischemia, thereby reducing the neurofunctional impairment caused by stroke, when considering the maintenance of muscle strength in the treated animals.

Salvianolic acid A protects against myocardial ischemia/reperfusion injury by reducing platelet activation and inflammation.

The aim of the present study was to investigate the protective effect of salvianolic acid A (SAA) on myocardial ischemia/reperfusion injury in rats. SAA (10 mg/kg) or Tirofiban (60 µg/kg) was administered to rats by jugular vein injection 10 min before the initiation of reperfusion. After 3 h of reperfusion, platelet aggregation was measured using an aggregometer and levels of nitric oxide (NO) were detected using an ultraviolet spectrophotometer. Serum levels of cardiac troponin T (cTnT), creatine kinase isoenzyme MB (CK-MB), p-selectin, interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α) were also measured 3 and 24 h after reperfusion. Furthermore, morphology of the ischemic myocardium was histopathologically analyzed by hematoxylin and eosin staining, and the infarct area was evaluated by Evans blue and triphenyltetrazolium chloride staining. In rats subjected to reperfusion, it was observed that pretreatment with SAA significantly increased the survival rate (P<0.05), and that increased survival rate was due to a significant decrease in infarct size, as evidenced by significantly reduced serum levels of cTnT and CK-MB (P<0.05). In addition, decreases in infarct size occurred through the inhibition of platelet aggregation and inflammation associated with reperfusion-induced myocardial cell damage, as indicated by reduced serum levels of p-selectin, TNF-α, IL-1ß and NO. In conclusion, SAA was protective against myocardial ischemia/reperfusion injury in rats by serving antiplatelet and anti-inflammation roles.

Neuroprotective effect of angiotensin II type 2 receptor during cerebral ischemia/reperfusion.

Angiotensin II type 2 receptor (AT2R) activation has been shown to protect against stroke, but its precise mechanism remains poorly understood. We investigated whether the protective effect of AT2R against ischemia/reperfusion injury is mediated by the suppression of immune and inflammatory responses. Rat models of middle cerebral artery occlusion were intraperitoneally injected with physiological saline, the AT2R agonist CGP42112 (1 mg/kg per day) or antagonist PD123319 (1 mg/kg per day). In the CGP42112 group, AT2R expression increased, the infarct area decreased, interleukin-1ß and tumor necrosis factor-α expression decreased, and interleukin-10 expression increased compared with the saline group. Antagonisin AT2R using PD123319 produced the opposite effects. These results indicate that AT2R activation suppresses immune and inflammatory responses, and protects against cerebral ischemia/reperfusion injury.

Neuroprotective effects of Tilia americana var. mexicana on damage induced by cerebral ischaemia in mice.

Tilia americana var. mexicana (T. americana) is a plant widely used in Mexico for its medicinal properties on the central nervous system. In the present study, we designed a protocol to investigate the neuroprotective effects of non-polar and polar extracts of T. americana on damage induced by cerebral ischaemia in mice. Vehicle or extracts were administered immediately after ischaemia. Functional neurological deficit, survival percentage and infarct area were determined in each experimental group. Results showed that groups treated with non-polar or polar extracts of T. americana had increased survival rate, improved neurological deficits and diminished the infarct area in relation to the ischaemic group. In conclusion, this study confirms the neuroprotective activity of T. americana, suggests a possible synergism between non-polar and polar constituents and supports its potential as a useful aid in the clinical management of stroke.

Establishment of a myocardial infarction model and the gene expression profile in peri-infarct area in Juema minipigs / 中国实验动物学报

Objective To establish a Juema minipig model of myocardial infarction, to evaluate the clinical indi?ces in the model pigs, and to explore the relationship between gene expression and metabolic decompensation. Methods 13 male Juema minipigs were randomly divided into control (Sham, n=5), myocardial infarction (MI, n=5) and normal control (for evaluating the recovery condition after surgery, n=3) groups. In the MI group, the ligation was done at the left descending coronary artery around the 1/3 distance to heart apex. Four weeks after the surgery, the cardiac function and serum biochemistry was analyzed. The histological changes and gene expression profiles in the myocardium in the peri?infarct area were exanimated. Results Ultrasonic images showed that the infarction was formed, the ejection fraction and fraction shortening were significantly reduced in the MI group ( ~32% and ~40% less than those of the sham group). Histological examination showed that myocardial fibers at the peri?infarct area were broken, dissolved, and there was con?nective tissue hyperplasia with increased neutrophil and lymphocyte infiltration. Microarray analysis revealed that two myo?cardial remodeling and pathology mediating pathways, three inflammation?related pathways, and 8 metabolic pathways ( in?cluding fatty acid, amino acid, and glucose metabolic pathways) were significantly changed. Conclusions We have suc?cessfully established a Juema minipig model of myocardial infarction. The less branches of the left descending coronary ar?tery allow us to establish a stable model by surgery with comparable characteristics in the clinic indices. The results of this study provides useful reference characteristics of an animal model with characteristic changes in the peri?infarct area.

Analysis of the correlation between three evaluation methods of rat models of focal cerebral ischemia/reperfusion / 中国实验动物学报

Objective To analyze the correlation between three evaluation methods of middle cerebral artery occlu -sion and focal cerebral ischemia , and to explore a new method and standard for the evaluation of the model .Method Thirty healthy adult male SD rats were randomly divided into a sham-operated group ( n=20 ) and model group .According to Zea-Longa procedure ,we established the disease model to detect the changes in cerebral blood flow before and after sur -gery.The resulted cerebral infarction area was taken as gold standards .Then we analyzed the correlation between the standards and the changes in cerebral blood flow .Results The changes of infarction area ratio were positively correlated with the changes of cerebral blood flow in the model rats .Conclusions The changes of rat cerebral blood flow can be used to evaluate whether the cerebral ischemia model is successful or not .

Intraperitoneal bilirubin administration decreases infarct area in a rat coronary ischemia/reperfusion model.

Bilirubin was previously considered a toxin byproduct of heme catabolism. However, a mounting body of evidence suggests that at physiological doses, bilirubin is a powerful antioxidant and anti-atherosclerotic agent. Recent clinical studies have shown that human beings with genetically-induced hyperbilirubinemia (Gilbert Syndrome) are protected against coronary heart disease. The purpose of this study was to investigate whether administration of exogenous bilirubin to normal rats would convey similar protective effects in an experimental model of coronary ischemia. We hypothesized that intraperitoneal bilirubin administration 1 h before injury would decrease infarct area and preserve left ventricular (LV) systolic function when compared to non-treated rats. Coronary ischemia was induced by temporary (30 min) ligation of the left anterior descending coronary artery in control or bilirubin treated rats, followed by a 1-h period of reperfusion. LV function was estimated by measurements of fractional shortening (FS) and fractional area shortening using echocardiography. LV function decreased in both experimental groups after ischemia and reperfusion, although in bilirubin-treated rats FS was less depressed during the period of ischemia (18.8 vs. 25.8%, p = 0.034). Infarct size was significantly reduced in the bilirubin treated group compared to the non-treated group (13.34 vs. 25.5%, p = 0.0067). Based on the results of this study, bilirubin supplementation appears to provide significant decrease in infarct size although protective effects on LV function were noted only during the period of ischemia. This result also suggests that lipid soluble antioxidant bilirubin prevents the oxidation of cardiolipin and decreases the infarct size in the heart during ischemia.

Cardioprotective and ß-adrenoceptor antagonistic activity of a newly synthesized aryloxypropanolamine derivative PP-36.

The present study was performed to evaluate the cardioprotective effects and pharmacological characterization of newly synthesized ß-adrenoreceptor antagonists 3-(3-tert-butylamino-2-hydroxypropoxy)-4-methoxybenzaldehyde (PP-36) in the rat model of coronary artery occlusion and reperfusion. Pre-ischemic administration (20 minutes before coronary occlusion) of PP-36 showed cardioprotective effects against ischemia/reperfusion injury in rats. PP-36 (6 mg kg(-1)) significantly reduced arrhythmia score (6.33 ± 0.55, P < 0.05), infarct size/left ventricle size (38.9 ± 3.2, P < 0.05) and no mortality compared to vehicle-treated control group (14.17 ± 1.83, 44.9 ± 4.6 and 17% respectively). In-vitro studies in rat isolated right atria, guinea-pig trachea and rat distal colon preparations, were carried out to investigate the potency of PP-36 towards different ß-adrenoceptor subtypes. pA2/pKB values of PP-36 for ß1-ß2-and ß3-adrenoceptors were 6.904 ± 0.190, 6.44 ± 0.129 and 5.773 ± 0.129, respectively. In conclusion, PP-36 is a ß-adrenoceptor antagonist possessing potent anti-arrhythmic and cardioprotective effects against ischemia/reperfusion injury in rats.