Evans Blue Content Research Articles

3'-Daidzein sulfonate sodium inhibits neuronal apoptosis induced by cerebral ischemia-reperfusion.

This study aimed to observe the effects of 3'-daidzein sulfonate sodium(DSS) on ischemia-reperfusion-induced brain injury and to analyze the mechanisms responsible for neuronal apoptosis. Focal ischemias were induced in male Sprague-Dawley rats using middle cerebral artery occlusion. The rats were divided into 5groups based on sham surgery or real occlusion, and treatment with different doses of DSS(0.5, 1.0and2.0mg/kg) or normal saline(model group), injected preoperatively into the rats with cerebral occlusion. After 2h of ischemia and 24h of reperfusion, neurological deficit scores were evaluated using the Longa grade point standard. The infarct volume was measured using a triphenyl tetrazolium chloride staining technique. Blood-brain barrier(BBB) permeability was measured using the Evansblue(EB) content of brain tissues, while electron microscopy was used to observe ultrastructural changes. The expression levels of Bcl-2, Bax and caspase-3 were detected by an immunohistochemical method and western blot analysis. The neurological deficit in rats pre-treated with DSS at all doses decreased significantly(P<0.05) in comparison with the model group, as did the cerebral infarct volume ratios. The brain EB content was significantly reduced by the injection of DSS. The ultrastructural integrity of the rat BBB was significantly preserved in the DSS-treated groups in comparison with the model group. This was concomitant with the reduced swelling of astrocytes and pericytes in the BBB. The immunohistochemistry results revealed that DSS significantly enhanced the expression of Bcl-2, and inhibited the expression of Bax and caspase-3 in the brain in comparison to the model group. The number of apoptotic cells in the groups treated with DSS was reduced in comparison with similar areas in the model group. These findings suggest that DSS within a dosage range of 0.5-2.0mg/kg provides significant protection from injury to the BBB induced by cerebral ischemia-reperfusion, as it exerts a neuroprotective effect by inhibiting apoptosis.

Repair mechanisms of the wounds with exposed bone structures using an artificial dermis

Objective: To investigate the repair mechanisms of the wounds with bone exposed by artificial dermis transplantation. Methods: Seventy two rabbits were randomly divided into 3 groups of 24 rabbits, the wound model was made on the top of head. In the skin defect group (SD group), skin was removed and skull periosteum was retained. In the periosteal defect group (PD group), the skin and skull periosteum were both removed, and the skull was exposed. In the skull burn group (SB group), after the periosteum was removed, the exposed skull bone was burned out with electric iron to cause skull surface necrosis, then the artificial dermis transplantation were performed in each group. In 1, 2, 3 and 4 weeks after transplantation, 2 specimens including artificial dermis and the underlying tissue in each group were cut for biopsy with HE staining to observe the angiogenesis in artificial dermis. Evans Blue perfusion was performed in four animals from each group to quantify angiogenesis in artificial dermis. Results: One week after transplantation, in SD group, a few microvessels can be observed in artificial dermis, but in the rest of the two groups, only a small amount of inflammatory cells can be seen. Two weeks after transplantation, in SD group, a large number of new blood vessels and fibroblasts can be seen filling in the artificial dermis, but angiogenesis delayed obviously in the PD and SB group. Three weeks after transplantation, the angiogenesis of artificial dermis in the PD and SB group accelerated obviously, and a thin layer of blood rich tissue membrane can be seen over the burned skull. The Evans Blue perfusion showed that the content of dye perfusion in the artificial dermis was closed to the peek value at 2 weeks after transplantation in the SD group, which was significantly higher than that in PD and SB group [(2 741±976) vs (1 039±590) and (403±209) μg/g, P<0.01]. Three weeks after transplantation, the content of Evans Blue in artificial dermis reached the peek value in SD and PD group, no significant difference was found between this two groups, but both significantly higher than that in SB group [(2 943±793) and (2 255±316) vs (1 125±404) μg/g, P<0.01]. Four weeks after transplantation, the content of Evans Blue in artificial dermis reached the peek value in SB group, although the value was still lower than that in SD and PD group, the difference was not significant [(1 609±787) vs (2 298±778) and (2 141±385) μg/g, P>0.05]. Conclusions: Lack or injury of periosteum can cause vascularization delay after artificial dermis transplantation. The vascularization of artificial dermis mainly originates from the normal tissues surrounding the wound when artificial dermis is transplanted on the wound with periosteum defect or bone exposed.

Time-course investigation of blood-brain barrier permeability and tight junction protein changes in a rat model of permanent focal ischemia.

Permanent middle cerebral artery occlusion (pMCAO) is an animal model that is widely used to simulate human ischemic stroke. However, the timing of the changes in the expression of tight junction (TJ) proteins and synaptic proteins associated with pMCAO remain incompletely understood. Therefore, to further explore the characteristics and mechanisms of blood-brain barrier (BBB) damage during cerebral ischemic stroke, we used a pMCAO rat model to define dynamic changes in BBB permeability within 120h after ischemia in order to examine the expression levels of the TJ proteins claudin-5 and occludin and the synaptic proteins synaptophysin (SYP) and postsynaptic density protein 95 (PSD95). In our study, Evans blue content began to increase at 4h and was highest at 8 and 120h after ischemia. TTC staining showed that cerebral infarction was observed at 4h and that the percentage of infarct volume increased with time after ischemia. The expression levels of claudin-5 and occludin began to decline at 1h and were lowest at 8 and 120h after ischemia. The expression levels of SYP and PSD95 decreased from 12 to 120h after ischemia. GFAP, an astrocyte marker, gradually increased in the cortex penumbra over time post-ischemia. Our study helps clarify the characteristics of pMCAO models and provides evidence supporting the translational potential of animal stroke models.

Hydrogen-Rich Saline Attenuates Brain Injury Induced by Cardiopulmonary Bypass and Inhibits Microvascular Endothelial Cell Apoptosis Via the PI3K/Akt/GSK3β Signaling Pathway in Rats

Background/Aims: Cardiopulmonary bypass (CPB) is prone to inducing brain injury during open heart surgery. A hydrogen-rich solution (HRS) can prevent oxidation and apoptosis, and inhibit inflammation. This study investigated effects of HRS on brain injury induced by CPB and regulatory mechanisms of the PI3K/Akt/GSK3β signaling pathway. Methods: A rat CPB model and an in vitro cell hypoxia model were established. After HRS treatment, Rat behavior was measured using neurological deficit score; Evans blue (EB) was used to assess permeability of the blood-brain barrier (BBB); HE staining was used to observe pathological changes; Inflammatory factors and brain injury markers were detected by ELISA; the PI3K/Akt/GSK3β pathway-related proteins and apoptosis were assessed by western blot, immunohistochemistry and qRT –PCR analyses of brain tissue and neurons. Results: After CPB, brain tissue anatomy was disordered, and cell structure was abnormal. Brain tissue EB content increased. There was an increase in the number of apoptotic cells, an increase in expression of Bax and caspase-3, a decrease in expression of Bcl2, and increases in levels of Akt, GSK3β, P-Akt, and P-GSK3β in brain tissue. HRS treatment attenuated the inflammatory reaction ,brain tissue EB content was significantly reduced and significantly decreased expression levels of Bax, caspase-3, Akt, GSK3β, P-Akt, and P-GSK3β in the brain. After adding the PI3K signaling pathway inhibitor, LY294002, to rat cerebral microvascular endothelial cells (CMECs), HRS could reduce activated Akt expression and downstream regulatory gene phosphorylation of GSK3β expression, and inhibit CMEC apoptosis. Conclusion: The PI3K/Akt/GSK3β signaling pathway plays an important role in the mechanism of CPB-induced brain injury. HRS can reduce CPB-induced brain injury and inhibit CMEC apoptosis through the PI3K/Akt/GSK3β signaling pathway.

Quantification of Tumor Vascular Permeability and Blood Volume by Positron Emission Tomography.

Purpose: Evans Blue (EB) is an azo dye that binds quantitatively with serum albumin. With an albumin binding, NOTA conjugated truncated Evan's blue (NEB) dye derived PET tracer, we aimed to establish a strategy for evaluating vascular permeability in malignant tumors via non-invasive PET. Experimental design: Sixty-minute dynamic PET using [18F]FAl-NEB was performed in three xenograft tumor models including INS-1 rat insulinoma, UM-SCC-22B human head and neck carcinoma and U-87 MG human glioblastoma. Tumor vascular permeability was quantified by the difference of the slopes between tumor and blood time-activity curve (TACs, expressed as Ps). The method was further substantiated by EB extraction and colorimetric assay and correlates with that calculated from dynamic contrast enhanced magnetic resonance imaging (DCE-MRI). The changes in tumor vasculature at different time points were assessed with NEB PET in U-87 MG and UM-SCC-22B tumor models after treatment with bevacizumab or doxorubicin. Result: The Ps values calculated from tumor and blood TACs from multiple time-point static images are consistent with those from dynamic images. Moreover, the Ps showed a positive and significant correlation with extracted EB concentration and KPS-MRI generated from DCE-MRI, which further confirmed the soundness of this methodology. The antiangiogenic effect of bevacizumab could be revealed by NEB PET in U-87 MG tumors as early as 8 hrs after therapy, demonstrated by a substantial decrease of Ps. On the contrary, there was no significant change of Ps in bevacizumab treated UM-SCC-22B tumors, compared with control group. However, the significant changes of Pswere overestimated in doxorubicin treated UM-SCC-22B tumors. Conclusions: We successfully developed a relatively convenient and novel strategy to evaluate vascular permeability and blood volume using NEB PET. This method will be advantageous in evaluating vascular permeability, promoting drug delivery, and monitoring tumor response to therapeutics that affect tumor angiogenesis.

Microcirculatory Disorders and Protective Role of Antioxidant in Severe Heat Stroke: A Rat Study.

This study aims to examine microcirculation and systemic hemodynamic disturbances in severe heat stroke (HS). A total of 147 rats were divided into HS group (HS), pretreated with superoxide dismutase (SOD+HS) group, and pretreated with normal saline (NS+HS) group. Heat stress was induced by incubating the animals in certain temperatures. Blood flow and vascular reactivity were monitored dynamically with intravital microscopy. Pulmonary permeability was reflected by wet-to-dry weight ratio, the concentration of Evans Blue (EB), and histopathology of lung. The results showed that heat stress could induce blood flow rate reduced, and SOD exhibited better protective role in blood flow rate. The arteriolar reactivity threshold to norepinephrine was markedly reduced at core temperature of 41°C, but no significant decrease occurred in SOD+HS group. Water content and EB concentration in lung tissue in HS group were increased along with temperature rise. SOD treatment could attenuate those changes. The pathological lung injury caused by heat stress was also milder in SOD+HS group than that in other two groups. Mean arterial pressure decreased at early stages of heat stress, but there was no decrease in SOD+HS group. There was a significant body weight loss during heat stress in all groups. Survival time in SOD+HS group was longer than that in other two groups. These results suggest that microcirculation disturbance occurs not only at the early stage but also before systemic hemodynamic disorder, monitoring microcirculation following HS is of prognostic value, and intervention with antioxidative agents may have certain protecting effects in severe HS.

PROTECTIVE EFFECTS OF ETHYL ACETATE EXTRACTION FROM GASTRODIA ELATA BLUME ON BLOOD-BRAIN BARRIER IN FOCAL CEREBRAL ISCHEMIA REPERFUSION.

Background:Damage of the blood brain barrier (BBB) during the process of cerebral ischemic injury is a key factor which influences the therapeutic efficacy to the cerebral ischemic injury. The present study was designed to verify the mechanisms underlying the protective effects of the ethyl acetate (EtOAc) extraction from Gastrodia elata Blume (GEB) on the BBB by developing a model of cerebral ischemia-reperfusion in rats.Material and methods:MCAO/R model in rats was developed through a thread embolism method. The neurological scales, the moisture and the evans blue (EB) contents of brains were detected. Meanwhile, the release of nitric oxide (NO) and activities of NO synthase (NOS) in brain tissues were measured. Western blotting analyses were also performed to assess the protein expressions of AQP-4, Occludin and Claudin-5 in brain tissue.Results:After rats were pretreated with different concentrations of EtOAc extractions from GEB, the neurologic scores, the EB contents in the brain tissues and the moisture of the brains were significantly decreased. Meanwhile, the release of NO, the activities of nNOS and iNOS were notably inhibited. Furthemore, the protein expression of AQP-4 was markedly decreased, but the protein expressions of -5 and Occludin were significantly increased.Conclusion:the EtOAc extracts of GEB may decrease the permeability of BBB when focal cerebral ischemia occurs. The inhibition of the NOS pathways, the attenuation of the protein expression of AQP-4 and the enhancement of the expressions of the tight junction proteins may contribute to the protective effects of the EtOAc extracts from GEB on BBB.

Pre-conditioning with transcranial low-level light therapy reduces neuroinflammation and protects blood-brain barrier after focal cerebral ischemia in mice.

Transcranial low-level light therapy (LLLT) has gained interest as a non-invasive, inexpensive and safe method of modulating neurological and psychological functions in recent years. This study was designed to examine the preventive effects of LLLT via visible light source against cerebral ischemia at the behavioral, structural and neurochemical levels. The mice received LLLT twice a day for 2 days prior to photothrombotic cortical ischemia. LLLT significantly reduced infarct size and edema and improved neurological and motor function 24 h after ischemic injury. In addition, LLLT markedly inhibited Iba-1- and GFAP-positive cells, which was accompanied by a reduction in the expression of inflammatory mediators and inhibition of MAPK activation and NF-κB translocation in the ischemic cortex. Concomitantly, LLLT significantly attenuated leukocyte accumulation and infiltration into the infarct perifocal region. LLLT also prevented BBB disruption after ischemic events, as indicated by a reduction of Evans blue leakage and water content. These findings were corroborated by immunofluorescence staining of the tight junction-related proteins in the ischemic cortex in response to LLLT. Non-invasive intervention of LLLT in ischemic brain injury may provide a significant functional benefit with an underlying mechanism possibly being suppression of neuroinflammation and reduction of BBB disruption.

Electroacupuncture preconditioning reduces ROS generation with NOX4 down-regulation and ameliorates blood-brain barrier disruption after ischemic stroke.

BackgroundElectroacupuncture (EA) is a modern application based on combination of traditional manual acupuncture and electrotherapy that is frequently recommended as an adjuvant treatment for ischemic stroke. EA preconditioning can ameliorate blood-brain barrier (BBB) dysfunction and brain edema in ischemia-reperfusion injury; however, its mechanism remains unclear. This study investigated the preventive effects of EA preconditioning, particularly on BBB injury, followed by a transient middle cerebral artery occlusion (MCAO) model in mice.ResultsMice were treated with EA (20 min) at Baihui (GV20) and Dazhui (GV14) acupoints once a day for 3 days before ischemic injury. Infarct volume, neurological deficits, oxidative stress, Evans blue leakage and brain edema were evaluated at 24 h after ischemia-reperfusion injury. EA preconditioning significantly decreased infarct volume and improved neurological function even after ischemic injury. In addition, both Evans blue leakage and water content were significantly reduced in EA preconditioned mice. Whereas the expression of tight junction proteins, ZO-1 and claudin-5, were remarkably increased by EA preconditioning. Mice with EA preconditioning showed the reduction of astrocytic aquaporin 4, which is involved in BBB permeabilization. In addition, we found that EA preconditioning decreased reactive oxygen species (ROS) in brain tissues after ischemic injury. The expression of NADPH oxidase 4 (NOX4), not NOX2, was significantly suppressed in EA preconditioned mice.ConclusionsThese results suggest that EA preconditioning improve neural function after ischemic injury through diminishing BBB disruption and brain edema. And, the reduction of ROS generation and NOX4 expression by EA preconditioning might be involved in BBB recovery. Therefore, EA may serve as a potential preventive strategy for patients at high risk of ischemic stroke.

Protective effect of rhEPO on tight junctions of cerebral microvascular endothelial cells early following traumatic brain injury in rats

Objective: The goal of this study was to investigate the protective effect of recombinant human EPO(rhEPO) on cerebral microvascular endothelial cells and the mechanisms by which rhEPO interacts with TJs proteins, claudin-5, Occludin and ZO-1 during the early period following traumatic brain injury.Research design: Rats (n = 81) were randomly divided into sham-operated group, TBI group and rhEPO+TBI group. Traumatic brain injury was induced by the Marmarou method.Methods and procedures: Rats were killed at 3, 24, 72 and 168 hours after TBI. The integrity of the blood–brain barrier was investigated by using a spectrophotometer to assess extravasation of Evans blue dye. The expression of Claudin-5, Occludin and ZO-1 were determined by immunohistochemistry and real-time fluorescence quantitative PCR.Results: From 3 hours to 3 days, rats in the TBI group demonstrated a remarkable increase in Evans blue content in the brain, relative to rats in the sham-operated group (p < 0.05). The expression of Claudin-5 and Occludin was significantly lower than those in the sham-operated group (p < 0.05). In contrast, rats in the TBI+rhEPO group demonstrated a significant decrease in brain levels.Conclusion: It was found that administration of rhEPO protected cerebral microvascular endothelial cells and reduced permeability of BBB and the mechanisms may be due to increasing the expression of TJs proteins.

Chromogranin A derived peptide CGA47-66 inhibits hyper-permeability of blood brain barrier in mice with sepsis

To explore the effect of chromofungin (CHR), a chromogranin A (CGA) derived peptide CGA47-66, on hyper-permeability of blood brain barrier in septic mice. 120 healthy male C57BL/6 mice were randomly divided into groups, with 12 mice in each group. Seventy-two mice were used for dynamic observation of the contents of water and Evan blue (EB) in brain tissue after being treated with lipopolysaccharide (LPS). Another 48 mice were divided into normal saline control group (NS group), LPS induced sepsis model group (LPS group), low-dose CHR pretreatment group (CL+LPS group), and high-dose CHR pretreatment group (CH+LPS group). The septic model was reproduced by intraperitoneal injection of 10 mg/kg LPS 0.1 mL, and the mice in NS group was given equal volume of normal saline. The mice in CL+LPS group and CH+LPS group were intraperitoneally injected with 15.5 μg/kg and 77.5 μg/kg CHR 10 minutes before LPS injection. Six hours after LPS injection, 4 mL/kg of 2% EB was injected via caudal vein, the contents of water and EB in brain tissue were determined, and EB immune fluorescence in brain tissue was determined to assess the changes in permeability of blood brain barrier. Brain pathology was observed with hematoxylin and eosin (HE) staining. With the extension of time after LPS injection, the contents of water and EB in brain tissue were gradually increased, and the time of difference with statistical significance appeared earlier when compared with that of control group in the contents of water than that in EB contents (3 hours and 6 hours, respectively). The contents of water and EB in brain tissue in LPS group were significantly increased as compared with NS group [water content: (79.77±0.62)% vs. (78.28±0.44)%, P < 0.01; EB content (μg/g): 13.87±4.50 vs. 7.13±1.76, P < 0.05]. CHR pretreatment with either of two dosages could reverse the increase in water and EB contents in brain tissue induced by LPS, and the effect was more significant in CH+LPS group [water content: (78.15±0.73)% vs. (79.77±0.62)%, EB (μg/g): 7.09±2.59 vs. 13.87±4.50, both P < 0.05]. It was shown by EB fluorescence observation that the fluorescence signal displayed only in the meninges in NS group, and EB fluorescence was widely distributed in brain parenchyma in LPS group, indicating that the EB leakage in LPS group was more marked than that of NS group. In CHR pretreatment groups, EB fluorescence was decreased in brain parenchyma, indicating that EB leakage was significantly less marked, while it was more obvious in high dose CHR group. It was shown by HE staining that cerebral blood vessel structure was intact in NS group, and the gap around blood vessel was not significant increased. On the other hand, brain structure in LPS group appeared loose, with widening of small perivascular spaces and obvious edema. Brain edema in CHR pretreatment groups was improved as compared with that of the LPS group, and it was more apparent in high dose CHR group. LPS induced change in blood brain barrier permeability in mice in a time-dependent manner. Exogenous CGA derived peptides CHR can inhibit LPS induced hyper-permeability of blood brain barrier in septic mice, thus reduces brain edema, protects the brain tissue, and the effect is more obvious with a high dose of CHR (77.5 μg/kg).

Enhancement of Small Molecule Delivery by Pulsed High-Intensity Focused Ultrasound: A Parameter Exploration

Chemotherapeutic drug delivery is often ineffective within solid tumors, but increasing the drug dose would result in systemic toxicity. The use of high-intensity focused ultrasound (HIFU) has the potential to enhance penetration of small molecules. However, operation parameters need to be optimized before the use of chemotherapeutic drugs in vivo and translation to clinical trials. In this study, the effects of pulsed HIFU (pHIFU) parameters (spatial-average pulse-average intensity, duty factor and pulse repetition frequency) on the penetration as well as content of small molecules were evaluated in ex vivo porcine kidneys. Specific HIFU parameters resulted in more than 40 times greater Evans blue content and 3.5 times the penetration depth compared with untreated samples. When selected parameters were applied to porcine kidneys in vivo, a 2.3-fold increase in concentration was obtained after a 2-min exposure to pHIFU. Pulsed HIFU has been found to be an effective modality to enhance both the concentration and penetration depth of small molecules in tissue using the optimized HIFU parameters. Although, performed in normal tissue, this study has the promise of translation into tumor tissue.

Enolase of Streptococcus Suis Serotype 2 Enhances Blood-Brain Barrier Permeability by Inducing IL-8 Release.

Streptococcus suis serotype 2 (SS2) is an emerging zoonosis, and meningitis is the most frequent clinical manifestation, but mechanism of its virulent factor, enolase (Eno), is unknown in meningitis. In this study, Eno was inducibly expressed and added to an in vitro Transwell co-culture model of the blood-brain barrier (BBB) consisted of porcine brain microvascular endothelial cells (PBMECs) and astrocytes (ACs), the results showed that Eno induces a significant increase in BBB permeability and promotes the release of IL-8 et al. cytokines. Furthermore, IL-8 could significantly destroy the integrity of the BBB model in vitro. In mice models administered Eno for 24h, Eno could significantly promote Evans blue (EB) moving from the blood to the brain and significantly increased the serum and brain levels of IL-8, as detected by ELISA. While G31P (IL-8 receptor antagonist) significantly decreased the concentration of EB in the brains of mice injected with Eno. The present study demonstrated that SS2 Eno may play an important role in disrupting BBB integrity by prompting IL-8 release.

Electroacupuncture Exerts Neuroprotection through Caveolin-1 Mediated Molecular Pathway in Intracerebral Hemorrhage of Rats

Spontaneous intracerebral hemorrhage (ICH) is one of the most devastating types of stroke. Here, we aim to demonstrate that electroacupuncture on Baihui (GV20) exerts neuroprotection for acute ICH possibly via the caveolin-1/matrix metalloproteinase/blood-brain barrier permeability pathway. The model of ICH was established by using collagenase VII. Rats were randomly divided into three groups: Sham-operation group, Sham electroacupuncture group, and electroacupuncture group. Each group was further divided into 4 subgroups according to the time points of 6 h, 1 d, 3 d, and 7 d after ICH. The methods were used including examination of neurological deficit scores according to Longa's scale, measurement of blood-brain barrier permeability through Evans Blue content, in situ immunofluorescent detection of caveolin-1 in brains, western blot analysis of caveolin-1 in brains, and in situ zymography for measuring matrix metalloproteinase-2/9 activity in brains. Compared with Sham electroacupuncture group, electroacupuncture group has resulted in a significant improvement in neurological deficit scores and in a reduction in Evans Blue content, expression of caveolin-1, and activity of matrix metalloproteinase-2/9 at 6 h, 1 d, 3 d, and 7 d after ICH (P < 0.05). In conclusion, the present results suggested that electroacupuncture on GV20 can improve neurological deficit scores and reduce blood-brain barrier permeability after ICH, and the mechanism possibly targets caveolin-1/matrix metalloproteinase/blood-brain barrier permeability pathway.

Effects of GSM modulated radio-frequency electromagnetic radiation on permeability of blood–brain barrier in male & female rats

With the increased use of mobile phones, their biological and health effects have become more important. Usage of mobile phones near the head increases the possibility of effects on brain tissue. This study was designed to investigate the possible effects of pulse modulated 900MHz and 1800MHz radio-frequency radiation on the permeability of blood–brain barrier of rats. Study was performed with 6 groups of young adult male and female wistar albino rats. The permeability of blood-brain barrier to intravenously injected evans blue dye was quantitatively examined for both control and radio-frequency radiarion exposed groups. For male groups; Evans blue content in the whole brain was found to be 0.08±0.01mg% in the control, 0.13±0.03mg% in 900MHz exposed and 0.26±0.05mg% in 1800MHz exposed animals. In both male radio-frequency radiation exposed groups, the permeability of blood–brain barrier found to be increased with respect to the controls (p<0.01). 1800MHz pulse modulated radio-frequency radiation exposure was found more effective on the male animals (p<0.01). For female groups; dye contents in the whole brains were 0.14±0.01mg% in the control, 0.24±0.03mg% in 900MHz exposed and 0.14±0.02mg% in 1800MHz exposed animals. No statistical variance found between the control and 1800MHz exposed animals (p>0.01). However 900MHz pulse modulated radio-frequency exposure was found effective on the permeability of blood-brain barrier of female animals. Results have shown that 20min pulse modulated radio-frequency radiation exposure of 900MHz and 1800MHz induces an effect and increases the permeability of blood-brain barrier of male rats. For females, 900MHz was found effective and it could be concluded that this result may due to the physiological differences between female and male animals. The results of this study suggest that mobile phone radation could lead to increase the permeability of blood-brain barrier under non-thermal exposure levels. More studies are needed to demonstrate the mechanisms of that breakdown.

Effect of penhyclidine hydrochloride on blood-brain barrier permeability in a rat model of lipopolysaccharide-induced brain injury

Objective To detect the effect of penhyclidine hydrochloride (PHC) on blood-brain barrier permeability in rats with lipopolysaccharide (LPS)-induced brain injury. Methods Eighty-one clear adult male SD rats were divided into control group, LPS group and PHC group according to the random number table, with 27 rats per group. The model of LPS-induced brain injury was established both in LPS and PHC groups. Rats were treated intraperitoneally with 2 mg/kg PHC in PHC group, while with the same volume of normal saline in control and LPS groups. Evans blue propagation through the brain was detected under the fluorescence microscope. Evans blue content was measured with a spectrophotometer. TNF-α content was measured with the Elisa assay. Brain water content was assessed with wet-to-dry weight ratios. Results Evans blue distribution in the cortex was obvious in LPS group, but decreased in PHC group. In control group contents of Evans blue in the cortex [(10.2±1.4)μg/g] and in the hippocampus[(11.3±0.8)μg/g] lowered as compared to these in LPS group [(234.8±14.7) and (23.1±1.9)μg/g] and PHC group [(71.0±8.7) and (15.2±1.9)μg/g] (P<0.01). Brain water content in control group was (73.5±1.8)%, increased to (85.3±1.6)% in LPS group and (78.9±1.2)% in PHC group (P<0.01). In control group contents of TNF-α in blood serum [(40.6±4.4) pg/ml], cerebrospinal fluid [(84.0±8.6)pg/ml] and brain tissue [(156.3±11.8) pg/ml] were significantly lower than these in LPS group[(93.4±7.2), (176.4±11.6) and (280.8±19.4)pg/ml] and PHC group[(79.9±5.9), (146.2±7.4) and (216.9±14.5) pg/ml] (P<0.01). And in comparison, all the measurements were lower in PHC group than in LPS group (P<0.01). Conclusion PHC can protect the BBB in rats with LPS-induced brain injury. Key words: Brain injuries; Blood-brain barrier; Penhyclidine hydrochloride

Effect of hypertonic saline on permeability of blood-brain barrier in a rat model of intracerebral hemorrhage

Objective To investigate the effect of hypertonic saline (HS) on the permeability of blood-brain barrier in a rat model of intracerebral hemorrhage (ICH). Methods Sixty healthy male Sprague-Dawley rats, aged 8 weeks, weighing 260-300 g, were randomly divided into 4 groups (n=15 each) using a random number table: sham operation group (group S), sham operation+ HS group (group HS), ICH group, and ICH+ HS group.ICH was commonly induced in anesthetized rats by intraparenchymal injection of autologous blood 50 μl.The equal volume of normal saline was given instead in group S. The neurologic deficits were scored on a five-point scale, and a score of 1-3 indicated successful establishment of the model.At 48 h after establishment of the model, the rats were sacrificed, and brains were removed for determination of brain water content, expression of occludin in brain tissues (by Western blot), and Evans blue content. Results Compared with group S, the brain water content and Evans blue content were significantly increased, and the expression of occludin was down-regulated in ICH and ICH+ HS groups, and no significant change was found in the indices mentioned above in group S+ HS.Compared with group ICH, the brain water content and Evans blue content were significantly decreased, and the expression of occludin was up-regulated in group ICH+ HS. Conclusion HS can inhibit increase in the permeability of blood-brain barrier, and reduce the cerebral edema in a rat model of ICH. Key words: Cerebral hemorrhage; Saline solution, hypertonic; Blood-brain barrier

Mesenteric Lymphatic-Perilymphatic Adipose Crosstalk: Role in Alcohol-Induced Perilymphatic Adipose Tissue Inflammation

The digestive tract lymphatics transport approximately two-thirds of all lymph produced in the body and have a key role in mucosal immunity through their contribution to antigen transport and immune cell trafficking. Mesenteric lymphatic pumping function integrity is critical for maintaining homeostasis and lipid transport. We previously demonstrated that acute alcohol intoxication (AAI) increases mesenteric lymphatic amplitude of contraction and ejection fraction, enhancing the ability of the lymphatic vessels to pump lymph. AAI has been shown to disrupt intestinal barrier integrity, which would be expected to increase the endotoxin content of mesenteric lymph. In this study, we tested the prediction that AAI increases lymphatic permeability directly affecting perilymphatic adipose tissue (PLAT) milieu. Male Sprague Dawley rats received an intragastric infusion of 2.5g/kg of alcohol. Isovolumic administration of water (vehicle) served as control. PLAT was isolated for the determination of Evans Blue extravasation (permeability), cytokine content, and immunohistochemistry for inflammatory cell infiltration at 30minutes and 24hours after alcohol administration. PLAT isolated from AAI animals had greater Evans Blue concentrations and cytokine expression (24hours post-AAI) and mast cell and neutrophil density than that isolated from controls. AAI resulted in significantly higher plasma lipopolysaccharide (endotoxin) levels, lower plasma adiponectin levels (at 30minutes), and unchanged plasma visfatin levels. The data indicate that AAI induces mesenteric lymphatic hyperpermeability, promotes PLAT inflammatory milieu and disrupts the systemic adipokine profile. These findings suggest an association between alcohol-induced lymphatic hyperpermeability and early manifestations of metabolic dysfunction as a result of alcohol abuse. We propose that crosstalk between lymph and PLAT results in adipose inflammation and adipokine dysregulation during AAI.

Microvessel permeability correlates with diabetic peripheral neuropathy in early stage of streptozotocin-induced diabetes rats

AimsThis study aims to explore the alterations in microvessel permeability in the sciatic nerve and whether they are associated with the development of diabetic peripheral neuropathy (DPN) during the early stage of diabetes in rats. MethodsSprague–Dawley rats were injected with streptozotocin and assessed at 0, 2, 4, and 8weeks. Rats in the control group received the vehicle. Changes in sciatic nerve pathology, nerve conductive velocity (NCV), permeability of microvessel, and levels of vascular endothelial growth factor (VEGF) were examined. ResultsThe morphology and NCV of sciatic nerves showed signs of abnormality as early as 2weeks after streptozotocin injection. The microvessel permeability as monitored by water and Evans blue content of sciatic nerve had increased dramatically at 4 and 8weeks. The water and Evans blue content both negatively correlated with NCV. VEGF was found in axons as well as the myelin sheaths in diabetic rats but not in control rats. ConclusionsThe permeability of sciatic nerves was associated with the development of DPN in the early stage of diabetes in rats. Increased expression of VEGF may have a crucial role in changes in microvessel permeability and DPN.

The Effects of Estrogen Receptors' Antagonist on Brain Edema, Intracranial Pressure and Neurological Outcomes after Traumatic Brain Injury in Rat.

Background:In previous studies, the neuroprotective effect of 17β-estradiol in diffuse traumatic brain injury has been shown. This study used ICI 182,780, a non-selective estrogen receptor antagonist, to test the hypothesis that the neuroprotective effect of 17β-estradiol in traumatic brain injury is mediated by the estrogen receptors. Methods: The ovariectomized rats were divided into eight groups. Brain injury was induced by Marmarou’s method. Estrogen was injected 30 minutes after traumatic brain injury, and ICI 182,780 was injected before traumatic brain injury and also before estrogen treatment. In one group only ICI 182,780 was injected. The brain water content and Evans blue dye content were measured 24 and 5 hours after traumatic brain injury, respectively. The neurologic outcomes and intracranial pressure were assessed before, 4, and 24 hours after traumatic brain injury. Results: Brain water content and Evans blue content were less in estrogen-treated group comparison to vehicle group. ICI 182,780 eliminated the effects of estrogen on brain edema and brain blood barrier permeability. Intracranial pressure was increased significantly after trauma, and estrogen decreased intracranial pressure at 4 and 24 hours after traumatic brain injury in comparison to vehicle. This inhibitory effect was also eliminated by treatment with ICI182,780. ICI 182,780 also inhibited the estrogen induced increase in neurologic outcomes following traumatic brain injury. However, the use of ICI 182,780 alone had no neuroprotective effect after traumatic brain injury. Conclusion: The results suggest that classical estrogen receptors have probably a role in the neuroprotective function of estrogen following traumatic brain injury.