scholarly journals Microvascular Changes during the Early Phase of Experimental Bacterial Meningitis

1990 ◽  
Vol 10 (6) ◽  
pp. 914-922 ◽  
Author(s):  
H.-W. Pfister ◽  
U. Koedel ◽  
R. L. Haberl ◽  
U. Dirnagl ◽  
W. Feiden ◽  
...  
Keyword(s):  
Free Radicals ◽  
Bacterial Meningitis ◽  
Water Content ◽  
Brain Edema ◽  
Early Phase ◽  
Brain Water Content ◽  
Edema Formation ◽  
Oxygen Derived Free Radicals ◽  
Brain Water ◽  
Brain Edema Formation

We investigated the temporal profile of the changes in regional CBF (rCBF) and intracranial pressure (ICP) during the early phase of pneumococcal meningitis in the rat. rCBF, as measured by laser-Doppler flowmetry, and ICP were continuously monitored during 6 h post infection (p.i.). Brain edema formation was assessed by brain water content determinations. Meningitis was induced by intracisternal injection of 75 μl of 107 colony-forming units/ml pneumococci (n = 7). In control animals (n = 6), saline was injected. There was no change in the rCBF or ICP of controls throughout the experiment. However, there was a dramatic increase in rCBF and ICP associated with brain edema formation in untreated meningitis animals. rCBF increased to 135.3 ± 33.8% (mean ± SD) in the untreated animals at 1 h p.i, and reached 211.1 ± 40.5% at 6 h p.i. (p < 0.05 compared with controls). ICP increased from 2.9 ± 1.4 to 10.4 ± 4.7 mm Hg at 6 h p.i. (p < 0.05 compared with controls). Brain water content was significantly elevated (79.69 ± 0.24 compared with 78.94 ± 0.16% in the control group, p < 0.05). We investigated the effect of dexamethasone (3 mg/kg i.p.), which was given prior to the induction of meningitis (n = 3) or at 2 h after pneumococcal injection (n = 5), indomethacin (10 mg/kg i.V., n = 5), and superoxide dismutase (SOD; 132,000 U/kg i.v. per 6 h, n = 6). The increases in rCBF and ICP were prevented by the pretreatment with dexamethasone and the administration of SOD, delayed and attenuated by pretreatment with indomethacin, and reversed by administration of dexamethasone 2 h p.i. These findings suggest that oxygen-derived free radicals are involved as mediators in the increases of rCBF and ICP and brain edema formation during the early phase of experimental bacterial meningitis. Arachidonic acid metabolites of the cyclooxygenase pathway are partially involved in the observed changes and are one possible source for the generation of oxygen-derived free radicals in bacterial meningitis.

Brain edema formation and neurological impairment after subarachnoid hemorrhage in rats

2009 ◽  
Vol 111 (5) ◽  
pp. 988-994 ◽  
Author(s):  
Serge C. Thal ◽  
Sonja Sporer ◽  
Mariusz Klopotowski ◽  
Simone E. Thal ◽  
Johannes Woitzik ◽  
...  
Keyword(s):  
Water Content ◽  
Brain Edema ◽  
Neuronal Cell ◽  
Cell Loss ◽  
Neurological Deficits ◽  
Brain Water Content ◽  
Edema Formation ◽  
Neuronal Cell Loss ◽  
Brain Water ◽  
Brain Edema Formation

Object Global cerebral edema is an independent risk factor for early death and poor outcome after subarachnoid hemorrhage (SAH). In the present study, the time course of brain edema formation, neurological deficits, and neuronal cell loss were investigated in the rat filament SAH model. Methods Brain water content and neurological deficits were determined in rats randomized to sham (1-, 24-, or 48-hour survival), SAH by endovascular perforation (1-, 24-, or 48-hour survival), or no surgery (control). The neuronal cell count (CA1–3) was quantified in a separate set of SAH (6-, 24-, 48-, or 72-hour survival) and shamoperated animals. Results Brain water content increased significantly 24 (80.2 ± 0.4% [SAH] vs 79.2 ± 0.1% [sham]) and 48 hours (79.8 ± 0.2% [SAH] vs 79.3 ± 0.1% [sham]) after SAH. The neuroscore was significantly worse after SAH (33 ± 15 [24 hours after SAH] vs 0 ± 0 points [sham]) and correlated with the extent of brain edema formation (r = 0.96, p < 0.001). No hippocampal damage was present up to 72 hours after SAH. Conclusions Brain water content and neurological dysfunction reached a maximum at 24 hours after SAH. This time point, therefore, seems to be optimal to test the effects of therapeutic interventions on brain edema formation. Neuronal cell loss was not present in CA1–3 up to 72 hours of SAH. Therefore, morphological damage needs to be evaluated at later time points.

Brain edema after intracerebral hemorrhage in rats: the role of iron overload and aquaporin 4

2009 ◽  
Vol 110 (3) ◽  
pp. 462-468 ◽  
Author(s):  
Wang Gai Qing ◽  
Yang Qi Dong ◽  
Tang Qing Ping ◽  
Li Guang Lai ◽  
Li Dong Fang ◽  
...  
Keyword(s):  
Iron Overload ◽  
Water Content ◽  
Brain Edema ◽  
Time Course ◽  
Iron Chelator ◽  
Brain Water Content ◽  
Edema Formation ◽  
Aqp4 Expression ◽  
The Right ◽  
Brain Water

Object Brain edema formation following intracerebral hemorrhage (ICH) appears to be partly related to erythrocyte lysis and hemoglobin release. An increase of brain water content was associated with an increase of brain iron, which is an erythrocyte degradation product. Expression of AQP4 is highly modified in several brain disorders, and it can play a key role in cerebral edema formation. However, the question whether AQP4 is regulated by drugs lacks reliable evidence, and the interacting roles of iron overload and AQP4 in brain edema after ICH are unknown. The goal of this study was to clarify the relationship between iron overload and AQP4 expression and to characterize the effects of the iron chelator deferoxamine (DFO) on delayed brain edema after experimental ICH. Methods A total of 144 Sprague-Dawley rats weighing between 250 and 300 g were used in this work. The animals were randomly divided into 4 groups. The ICH models (Group C) were generated by injecting 100 μl autologous blood stereotactically into the right caudate nucleus; surgical control rats (Group B) were generated in a similar fashion, by injecting 100 μl saline into the right caudate nucleus. Intervention models (Group D) were established by intraperitoneal injection of DFO into rats in the ICH group. Healthy rats (Group A) were used for normal control models. Brain water content, iron deposition, and AQP4 in perihematomal brain tissue were evaluated over the time course of the study (1, 3, 7, and 14 days) in each group. Results Iron deposition was found in the perihematomal zone as early as the 1st day after ICH, reaching a peak after 7 days and remaining at a high level thereafter for at least 14 days following ICH. Rat brain water content around the hematoma increased progressively over the time course, reached its peak at Day 3, and still was evident at Day 7 post-ICH. Immunohistochemical analysis showed that AQP4 was richly expressed over glial cell processes surrounding microvessels in the rat brain; there was upregulation of the AQP4 expression in perihematomal brain during the observation period, and it reached maximum at 3 to 7 days after ICH. The changes of brain water content were accompanied by an alteration of AQP4. The application of the iron chelator DFO significantly reduced iron overload, brain water content, and AQP4 level in the perihematomal area compared with the control group. Conclusions Iron overload and AQP4 may play a critical role in the formation of brain edema after ICH. In addition, AQP4 expression was affected by iron concentration. Importantly, treatment with DFO significantly reduced brain edema in rats and inhibited the AQP4 upregulation after ICH. Deferoxamine may be a potential therapeutic agent for treating ICH.

scholarly journals Pial Arterial Pressure Contribution to Early Ischemic Brain Edema

1989 ◽  
Vol 9 (5) ◽  
pp. 597-602 ◽  
Author(s):  
Shuhei Yamaguchi ◽  
Shotai Kobayashi ◽  
Kazuya Yamashita ◽  
Mitsuhiro Kitani
Keyword(s):  
Arterial Pressure ◽  
Water Content ◽  
Brain Edema ◽  
Peripheral Region ◽  
Core Region ◽  
Brain Water Content ◽  
Edema Formation ◽  
The Core ◽  
Mca Occlusion ◽  
Brain Water

The effect of pial arterial pressure (PAP) on brain edema was examined in cats with middle cerebral artery (MCA) occlusion. Measurements of PAP and regional CBF (rCBF) were collected in the central core and the peripheral margin of the MCA territory over 180 min post MCA occlusion. Brain water content in each region was determined at the end of the experiment. MCA occlusion resulted in decreased PAP and rCBF in both the core (PAP = 13 mm Hg, rCBF = 9 ml/100 g/min) and the peripheral region (PAP = 15 mm Hg, rCBF = 18 ml/100 g/min). Brain edema developed in both the core and the peripheral region. Brain water content was correlated inversely with PAP in the core region and positively in the peripheral region. The results indicate that decreased blood flow contributes to cytotoxic edema in the core, and a hydrostatic pressure gradient preferentially enhances edema formation in the peripheral region. Maintenance of high perfusion pressure early after ischemia onset may suppress brain edema in the core region.

scholarly journals Ulinastatin alleviates traumatic brain injury by reducing endothelin-1

2020 ◽  
Vol 12 (1) ◽  
pp. 001-008
Author(s):  
Ting Liu ◽  
Xing-Zhi Liao ◽  
Mai-Tao Zhou
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Western Blot ◽  
Water Content ◽  
Brain Edema ◽  
Rat Model ◽  
Neurosurgical Procedures ◽  
Brain Water Content ◽  
The Brain ◽  
Brain Water

Abstract Background Brain edema is one of the major causes of fatality and disability associated with injury and neurosurgical procedures. The goal of this study was to evaluate the effect of ulinastatin (UTI), a protease inhibitor, on astrocytes in a rat model of traumatic brain injury (TBI). Methodology A rat model of TBI was established. Animals were randomly divided into 2 groups – one group was treated with normal saline and the second group was treated with UTI (50,000 U/kg). The brain water content and permeability of the blood–brain barrier were assessed in the two groups along with a sham group (no TBI). Expression of the glial fibrillary acidic protein, endthelin-1 (ET-1), vascular endothelial growth factor (VEGF), and matrix metalloproteinase 9 (MMP-9) were measured by immunohistochemistry and western blot. Effect of UTI on ERK and PI3K/AKT signaling pathways was measured by western blot. Results UTI significantly decreased the brain water content and extravasation of the Evans blue dye. This attenuation was associated with decreased activation of the astrocytes and ET-1. UTI treatment decreased ERK and Akt activation and inhibited the expression of pro-inflammatory VEGF and MMP-9. Conclusion UTI can alleviate brain edema resulting from TBI by inhibiting astrocyte activation and ET-1 production.

scholarly journals Expression of IL-1β, IL-6 and TNF-α in rats with thioacetamide-induced acute liver failure and encephalopathy: correlation with brain edema

2011 ◽  
Vol 5 (2) ◽  
pp. 205-215 ◽  
Author(s):  
Li-Qing Wang ◽  
Heng-Jun Zhou ◽  
Cai-Fei Pan ◽  
Sheng-Mei Zhu ◽  
Lin-Mei Xu
Keyword(s):  
Hepatic Encephalopathy ◽  
Motor Activity ◽  
Water Content ◽  
Brain Edema ◽  
Proinflammatory Cytokines ◽  
Enzyme Linked Immunosorbent Assay ◽  
Brain Water Content ◽  
Tnf Α ◽  
The Relationship ◽  
Brain Water

Abstract Background: Secondary brain edema is a serious complication of hepatic encephalopathy (HE). Recently, it has been reported that proinflammatory cytokines are involved in the pathogenesis of brain edema during HE. Objectives: Observe the dynamic expressions of brain and plasma proinflammatory cytokines in encephalopathy rats, and evaluate the relationship between proinflammatory cytokines and brain edema. Methods: Acute HE rats were induced by intraperitoneal injection of thioacetamide (TAA) in 24 hours intervals for two consecutive days. Then, clinical symptom and stages of hepatic encephalopathy, motor activity counts, index of liver function, and brain water content were observed. The dynamic expressions of IL-1β, IL-6, and TNF-α in plasma and brain tissues were measured with enzyme-linked immunosorbent assay. Results: Typical clinical performances of hepatic encephalopathy were occurred in all TAA-administrated rats. The TAA rats showed lower motor activity counts and higher the index of alanine aminotransferase, aspartate aminotransferase, total bilirubin and ammonia than those in control rats. Brain water content was significantly enhanced in TAA rats compared with the control. The expressions of IL-1β, IL-6, and TNF- α in plasma and brain significantly increased in TAA rats. In addition, the expressions of cerebral proinflammatory cytokines were positively correlated with brain water content but negatively correlated with motor activity counts.Conclusion: Inflammation was involved in the pathogenesis of brain edema during TAA-induced HE.

scholarly journals Neuroprotection of Sanhua Decoction against Focal Cerebral Ischemia/Reperfusion Injury in Rats through a Mechanism Targeting Aquaporin 4

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Lin Lu ◽  
Hui-qin Li ◽  
Ji-huang Li ◽  
Ai-ju Liu ◽  
Guo-qing Zheng
Keyword(s):  
Cerebral Ischemia ◽  
Water Content ◽  
Brain Edema ◽  
Focal Cerebral Ischemia ◽  
Ischemia Reperfusion ◽  
Aquaporin 4 ◽  
Brain Water Content ◽  
Aqp4 Expression ◽  
Cerebral Ischemia Reperfusion ◽  
Brain Water

Sanhua decoction (SHD) is a famous classic Chinese herbal prescription for ischemic stroke, and aquaporin 4 (AQP4) is reported to play a key role in ischemic brain edema. This study aimed to investigate neuroprotection of SHD against focal cerebral ischemia/reperfusion (I/R) injury in rats and explore the hypothesis that AQP4 probably is the target of SHD neuroprotection against I/R rats. Lentiviral-mediated AQP4-siRNA was inducted into adult male Sprague-Dawley rats via intracerebroventricular injection. The focal cerebral ischemia/reperfusion model was established by occluding middle cerebral artery. Neurological examinations were performed according to Longa Scale. Brain water content, was determined by wet and dry weight measurement. Western blot was adopted to test the AQP4 expression in ipsilateral hippocampus. After the treatment, SHD alleviated neurological deficits, reduced brain water content and downregulated the expression of AQP4 at different time points following I/R injury. Furthermore, neurobehavioral function and brain edema after I/R were significantly attenuated via downregulation of AQP4 expression when combined with AQP4-siRNA technology. In conclusion, SHD exerted neuroprotection against focal cerebral I/R injury in rats mainly through a mechanism targeting AQP4.

scholarly journals Hydrochloride fasudil attenuates brain injury in ICH rats

2020 ◽  
Vol 11 (1) ◽  
pp. 75-86
Author(s):  
Limin Li ◽  
Xiaoli Lou ◽  
Kunlun Zhang ◽  
Fangping Yu ◽  
Yingchun Zhao ◽  
...  
Keyword(s):  
Water Content ◽  
Brain Edema ◽  
Inflammatory Cytokines ◽  
Neuronal Morphology ◽  
Enzyme Linked Immunosorbent Assay ◽  
Brain Water Content ◽  
Nissl Staining ◽  
Neuroprotective Effects ◽  
Arterial Blood ◽  
Brain Water

AbstractAimThe aim of this study was to investigate the neuroprotective effects of hydrochloride fasudil (HF) in rats following intracerebral hemorrhage (ICH).MethodsMale Wistar rats were randomly divided into four groups: normal, sham-operated, ICH, and ICH/HF. ICH was induced by injection of non-anticoagulant autologous arterial blood into the right caudate nucleus. The levels of Rho-associated protein kinase 2 (ROCK2) mRNA and protein around the site of the hematoma were measured by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay (ELISA), respectively. The levels of interleukin-6 and tumor necrosis factor-α in serum were detected by ELISA. The inflammatory cells and changes in the neuronal morphology around the hematoma were visualized using hematoxylin and eosin and Nissl staining. Brain edema was measured by comparing wet and dry brain weights.ResultsFollowing ICH, the levels of ROCK2 were significantly increased from day 1 to day 7. The levels of ROCK2 were significantly lower in rats treated with HF than in controls. The levels of inflammatory cytokines and brain water content were significantly higher in rats treated with HF than in controls. Administration of HF significantly reduced the levels of inflammatory cytokines and brain water content from day 1 to day 7. In the acute phase of ICH, a large number of neutrophils infiltrated the perihematomal areas. In comparison with the ICH group, the ICH/HF group showed markedly fewer infiltrating neutrophils on day 1. Nissl staining showed that ICH caused neuronal death and loss of neurons in the perihematomal areas at all time points and that treatment with HF significantly attenuated neuronal loss.ConclusionsHF exerts neuroprotective effects in ICH rats by inhibiting the expression of ROCK2, reducing neutrophil infiltration and production of inflammatory cytokines, decreasing brain edema, and attenuating loss of neurons.

Erythrocytes and delayed brain edema formation following intracerebral hemorrhage in rats

1998 ◽  
Vol 89 (6) ◽  
pp. 991-996 ◽  
Author(s):  
Guohua Xi ◽  
Richard F. Keep ◽  
Julian T. Hoff
Keyword(s):  
Intracerebral Hemorrhage ◽  
Brain Edema ◽  
Sprague Dawley ◽  
Edema Formation ◽  
Content Type ◽  
Packed Red Blood Cells ◽  
Brain Water ◽  
Packed Rbcs ◽  
Brain Edema Formation ◽  
Fine Print

Object. The mechanisms of brain edema formation following spontaneous intracerebral hemorrhage (ICH) are not well understood. In previous studies, no significant edema formation has been found 24 hours after infusion of packed red blood cells (RBCs) into the brain of a rat or pig; however, there is evidence that hemoglobin can be neurotoxic. In this study, the authors reexamined the role of RBCs and hemoglobin in edema formation after ICH. Methods. The experiments involved infusion of whole blood, packed RBCs, lysed RBCs, rat hemoglobin, or thrombin into the right basal ganglia of Sprague—Dawley rats. The animals were killed at different time points and brain water and ion contents were measured. The results showed that lysed autologous erythrocytes, but not packed erythrocytes, produced marked brain edema 24 hours after infusion and that this edema formation could be mimicked by hemoglobin infusion. Although infusion of packed RBCs did not produce dramatic brain edema during the first 2 days, it did induce a marked increase in brain water content 3 days postinfusion. Edema formation following thrombin infusion peaked at 24 to 48 hours. This is earlier than the peak in edema formation that follows ICH, suggesting that there is a delayed, nonthrombin-mediated, edemogenic component of ICH. Conclusions. These results demonstrate that RBCs play a potentially important role in delayed edema development after ICH and that RBC lysis and hemoglobin toxicity may be useful targets for therapeutic intervention.

Contribution of vasogenic and cellular edema to traumatic brain swelling measured by diffusion-weighted imaging

1997 ◽  
Vol 87 (6) ◽  
pp. 900-907 ◽  
Author(s):  
Pál Barzó ◽  
Anthony Marmarou ◽  
Panos Fatouros ◽  
Koji Hayasaki ◽  
Frank Corwin
Keyword(s):  
Water Content ◽  
Diffusion Weighted Imaging ◽  
Vasogenic Edema ◽  
Brain Water Content ◽  
Brain Swelling ◽  
Edema Formation ◽  
Content Type ◽  
Diffusion Weighted ◽  
Brain Water ◽  
Fine Print

✓ The contribution of brain edema to brain swelling in cases of traumatic brain injury remains a critical problem. The authors believe that cellular edema, the result of complex neurotoxic events, is the major contributor to brain swelling and that vasogenic edema, secondary to blood-brain barrier compromise, may be overemphasized. The objective of this study, therefore, was to quantify temporal water content changes and document the type of edema that forms during the acute and late stages of edema development following closed head injury (CHI). The measurement of brain water content was based on magnetic resonance imaging—determined values of tissue longitudinal relaxation time (T1-weighted imaging) and their subsequent conversion to percentage of water, whereas the differentiation of edema formation (cellular vs. vasogenic) was based on the measurement of the apparent diffusion coefficient (ADC) by diffusion-weighted imaging. A new impact-acceleration model was used to induce CHI. Thirty-six adult Sprague—Dawley rats were separated into two groups: Group I, control (six animals); and Group II, trauma (30 animals). Fast ADC measurements (localized, single-voxel) were obtained sequentially (every minute) up to 1 hour postinjury. The T1-weighted images, used for water content determination, and the diffusion-weighted images (ADC measurement with conventional diffusion-weighted imaging) were obtained at the end of the 1st hour postinjury and on Days 1, 3, 7, 14, 28, and 42 in animals from the trauma and control groups. In the animals subjected to trauma, the authors found a significant increase in ADC (10 ± 5%) and brain water content (1.3 ± 0.9%) during the first 60 minutes postinjury. This is consistent with an increase in the volume of extracellular fluid and vasogenic edema formation as a result of blood-brain barrier compromise. This transient increase, however, was followed by a continuing decrease in ADC that began 40 to 60 minutes postinjury and reached a minimum value on Days 7 to 14 (10 ± 3% reduction). Because the water content of the brain continued to increase during the first 24 hours postinjury (1.9 ± 0.9%), it is suggested that the decreased ADC indicated cellular edema formation, which started to develop soon after injury and became dominant between 1 and 2 weeks postinjury. The study provides supportive evidence that cellular edema is the major contributor to posttraumatic swelling in diffuse CHI and defines the onset and duration of the increase in cellular volume.

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