scholarly journals Extracellular Antioxidants and Amino Acids in the Cortex of the Rat: Monitoring by Microdialysis of Early Ischemic Changes

1992 ◽  
Vol 12 (1) ◽  
pp. 96-102 ◽  
Author(s):  
H. Landolt ◽  
T. W. Lutz ◽  
H. Langemann ◽  
D. Stäuble ◽  
A. Mendelowitsch ◽  
...  
Keyword(s):  
Amino Acids ◽  
Ascorbic Acid ◽  
Uric Acid ◽  
Artery Occlusion ◽  
Left Middle Cerebral Artery ◽  
Sham Operation ◽  
Intracerebral Microdialysis ◽  
Microdialysis Probe ◽  
Cerebral Artery Occlusion ◽  
Ischemic Events

Extracellular concentrations of ascorbic acid, glutathione, cysteine, uric acid, tyrosine, and tryptophan were monitored using intracerebral microdialysis in the left frontoparietal cortex of spontaneous hypertensive rats before, and for 3 h after, either focal ischemia [left middle cerebral artery occlusion (MCAO)] or sham operation. The size of the ischemic area and the position of the microdialysis probe were checked using the enzyme histotopochemical acid phosphatase reaction. The probe was always located in the cortex inside the stained area. Ascorbic acid levels rose immediately after MCAO and remained at about 12-fold for 3 h. There was a transient release of glutathione during 1–1.5 h. Uric acid concentrations were also increased but the differences did not reach significance. The levels of the amino acids tyrosine and tryptophan increased steadily after MCAO. The increases in cysteine were variable but significant. In some experiments, the pH of the dialysate was measured online. The parameters ascorbic acid, glutathione, cysteine, and pH are suitable for the early detection of cortical ischemic events by microdialysis.

scholarly journals Dynamics of Extracellular Metabolites in the Striatum after Middle Cerebral Artery Occlusion in the Rat Monitored by Intracerebral Microdialysis

1989 ◽  
Vol 9 (5) ◽  
pp. 607-616 ◽  
Author(s):  
L. Hillered ◽  
A. Hallström ◽  
S. Segersvärd ◽  
L. Persson ◽  
U. Ungerstedt
Keyword(s):  
Amino Acids ◽  
Cerebral Ischemia ◽  
Middle Cerebral Artery ◽  
Middle Cerebral Artery Occlusion ◽  
Cerebral Artery ◽  
Focal Cerebral Ischemia ◽  
Artery Occlusion ◽  
Intracerebral Microdialysis ◽  
Dopamine Metabolites ◽  
Cerebral Artery Occlusion

The aim of this study was to measure changes in the extracellular fluid (ECF) concentration of lactate, pyruvate, purines, amino acids, dopamine, and dopamine metabolites in the striatum of rats subjected to focal cerebral ischemia, using intracerebral microdialysis as the sampling technique. Microdialysis probes were inserted into the lateral part of the caudate-putamen bilaterally 2 h before the experiment. Ischemia was induced by permanent middle cerebral artery occlusion (MCAO) on the left side. Microdialysis samples were analyzed by high performance liquid chromatography. Following MCAO, the concentration of lactate, adenosine, inosine, and hypoxanthine rose markedly in the ECF on the occluded side, while there was no significant change in pyruvate. These changes were accompanied by dramatically elevated levels of aspartate, glutamate, taurine, γ-aminobutyric acid, and dopamine. There was also a marked increase in alanine/tyrosine, while minor or no changes occurred with other amino acids. Concomitantly, the ECF level of the dopamine metabolites 3,4–dihydroxyphenylacetate and homovanillic acid decreased. There was no significant increase in any of the metabolites measured on the right, nonoccluded side. In relation to the concept of excitotoxicity in brain ischemia, it is concluded that during the acute stage of focal cerebral ischemia, the ECF is flooded with both potentially harmful (e.g., aspartate, glutamate, and DA) and protective (e.g., taurine, GABA, and adenosine) agents. The relative importance of these events for the development of cell death in the ischemic penumbra needs to be elucidated. In addition, lactate, inosine, and hypoxanthine, measured in the ECF by intracerebral microdialysis, may prove to have diagnostic and/or prognostic value in neurometabolic monitoring of the ischemic brain.

scholarly journals Uric acid promotes oxidative stress and enhances vascular endothelial cell apoptosis in rats with middle cerebral artery occlusion

2018 ◽  
Vol 38 (3) ◽  
Author(s):  
Chengfu Song ◽  
Xiangdong Zhao
Keyword(s):  
Oxidative Stress ◽  
Uric Acid ◽  
Endothelial Cell ◽  
Cell Apoptosis ◽  
Vascular Endothelial Cell ◽  
Artery Occlusion ◽  
Vascular Endothelial ◽  
Endothelial Cell Apoptosis ◽  
Related Factors ◽  
Cerebral Artery Occlusion

In patients with cerebral infarction (CI), elevated serum uric acid (UA) level may exacerbate the occurrence and development of carotid atherosclerosis (AS). Our study intended to explore the underlying mechanism. We enrolled 86 patients with CI, and divided them into four groups: Non-AS, AS-mild, AS-moderate, and AS-severe groups; the levels of UA and oxidative stress-related factors in serum were detected. The middle cerebral artery occlusion (MCAO) model was used to stimulate CI in rats, and different doses of UA were administrated. The levels of oxidative stress-related factors in serum were detected. Hematoxylin & eosin (H&E) staining was used to observe the morphological alterations, and the apoptotic cell death detection kit was used to detect apoptotic cells. Increased UA concentration and enhanced oxidative stress were found in AS patients. H&E staining results showed that UA treatment exacerbated morphological damage in rats with MCAO, promoted oxidative stress, and enhanced vascular endothelial cell apoptosis in rats with MCAO.

GABAergic contribution to rat bladder hyperactivity after middle cerebral artery occlusion

2000 ◽  
Vol 279 (4) ◽  
pp. R1230-R1238 ◽  
Author(s):  
Sayoko Kanie ◽  
Osamu Yokoyama ◽  
Kazuto Komatsu ◽  
Koichi Kodama ◽  
Satoshi Yotsuyanagi ◽  
...  
Keyword(s):  
Middle Cerebral Artery ◽  
Middle Cerebral Artery Occlusion ◽  
Cerebral Artery ◽  
Receptor Agonist ◽  
Bladder Capacity ◽  
Artery Occlusion ◽  
Female Rats ◽  
Left Middle Cerebral Artery ◽  
Urethral Pressure ◽  
Cerebral Artery Occlusion

To evaluate the influences of γ-aminobutyric acid (GABA) mechanisms on bladder hyperactivity after left middle cerebral artery occlusion, cystometric recordings were obtained from unanesthetized female rats. Intracerebroventricular administration of both muscimol (GABAA receptor agonist; 0.1–10 nmol) and baclofen (GABAB receptor agonist; 0.1–3 nmol) produced dose-dependent inhibitions of micturition with increases in bladder capacity (BC). The effects of high doses (1–10 nmol) were similar in sham-operated (SO) and cerebral-infarcted (CI) rats. However, lower doses of muscimol (0.1 or 0.3 nmol) and baclofen (0.1 nmol) reduced BC in CI rats. After bicuculline (GABAA receptor antagonist; 1 or 3 nmol) administration, BC in both SO and CI rats first decreased and subsequently increased. An increase in urethral pressure was observed after administration of bicuculline (3 nmol) but not with either muscimol or baclofen. Infarct volumes in muscimol-, bicuculline-, or baclofen-treated rats were not significantly different from those of vehicle-treated rats. These results suggest that GABAergic mechanisms inhibit the micturition reflex at the supraspinal level but that this can change as a result of CI.

scholarly journals The role of PI3K-mediated AMPA receptor changes in post-conditioning of propofol in brain protection

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Chenxu Wang ◽  
Ying Wei ◽  
Yuan Yuan ◽  
Yonghao Yu ◽  
Keliang Xie ◽  
...  
Keyword(s):  
Middle Cerebral Artery ◽  
Middle Cerebral Artery Occlusion ◽  
Cerebral Artery ◽  
Ischemia Reperfusion ◽  
Artery Occlusion ◽  
Sham Operation ◽  
Short Term ◽  
Selective Antagonist ◽  
Cerebral Artery Occlusion

Abstract Background We aimed to study the role of amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor (AMPAR) glutamate receptor 2 (GluR2) subunit trafficking, and activity changes in short-term neuroprotection provided by propofol post-conditioning. We also aimed to determine the role of phosphoinositide-3-kinase (PI3K) in the regulation of these processes. Methods Rats underwent 1 h of focal cerebral ischemia followed by 23 h of reperfusion were randomly divided into 6 groups (n = 36 per group): sham- operation (S), ischemia–reperfusion (IR), propofol (P group, propofol 20 mg/kg/h at the onset of reperfusion for 2 h after 60 min of occlusion), and LY294002 (PI3K non-selective antagonist) + sham (L + S, LY294002 of 1.5 mg/kg was infused 30 min before sham operation), LY294002+ ischemia–reperfusion (L + IR, LY294002 of 1.5 mg/kg was infused 30 min before middle cerebral artery occlusion), LY294002 + IR + propofol (L + P, LY294002 of 1.5 mg/kg was infused 30 min before middle cerebral artery occlusion and propofol 20 mg/kg/h at the onset of reperfusion for 2 h after 60 min of occlusion). Results Compared with group IR, rats in group P had significant lower neurologic defect scores and infarct volume. Additionally, consistent with enhanced expression of PI3K-AMPAR GluR2 subunit complex substances in ipsilateral hippocampus, GluR2 subunits showed increased levels in both the plasma and postsynaptic membranes of neurons, while pGluR2 expression was reduced in group P. Furthermore, LY294002, the PI3K non-selective antagonist, blocked those effects. Conclusion These observations demonstrated that propofol post-conditioning revealed acute neuroprotective role against transient MCAO in rats. The short-term neuroprotective effect was contributed by enhanced GluR2 subunits trafficking to membrane and postsynaptic membranes of neurons, as well as down-regulated the expression of pGluR2 in damaged hippocampus. Finally, the above-mentioned protective mechanism might be contributed by increased combination of PI3K to AMPAR GluR2 subunit, thus maintained the expression and activation of AMPAR GluR2 in the ipsilateral hippocampus.

scholarly journals Cortical Spreading Depression Protects against Subsequent Focal Cerebral Ischemia in Rats

1996 ◽  
Vol 16 (2) ◽  
pp. 221-226 ◽  
Author(s):  
Kazushi Matsushima ◽  
Matthew J. Hogan ◽  
Antoine M. Hakim
Keyword(s):  
Cerebral Ischemia ◽  
Cortical Spreading Depression ◽  
Spreading Depression ◽  
Focal Cerebral Ischemia ◽  
Infarct Volume ◽  
Occipital Cortex ◽  
Artery Occlusion ◽  
Microdialysis Probe ◽  
Cerebral Artery Occlusion ◽  
Subcortical Infarct

The possibility that cortical spreading depression (CSD) may have neuroprotective action during subsequent focal cerebral ischemia was examined in rats. Three days before the imposition of focal cerebral ischemia CSDs were elicited by applying potassium chloride (KCl) for 2 h through a microdialysis probe implanted in the occipital cortex. Control animals were handled identically except that saline was infused instead of KCl. Focal ischemia was produced by the intraluminal suture method and cortical and subcortical infarct volumes were measured 7 days later. Neocortical infarct volume was reduced from 124.8 ± 49.5 mm3 in the controls to 62.9 ± 59.5 mm3 in the animals preconditioned with CSD (p = 0.012). There was no difference between the two groups in the subcortical infarct volume or in CBF, measured by the hydrogen clearance method, during or immediately after the ischemic interval. Our data indicate that preconditioning CSD applied 3 days before middle cerebral artery occlusion may increase the brain's resistance to focal ischemic damage and may be used as a model to explore the neuroprotective molecular responses of neuronal and glial cells.

scholarly journals Successful Mechanical Thrombectomy of Middle Cerebral Artery Occlusion 14 Hours after Stroke Onset

2021 ◽  
Vol 3 (01) ◽  
pp. 42-44
Author(s):  
Robin Bhattarai ◽  
Karuna Tamrakar Karki ◽  
Dinesh Kumar Thapa ◽  
Navin Kumar Yadav
Keyword(s):  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Mechanical Thrombectomy ◽  
Artery Occlusion ◽  
Stroke Onset ◽  
Therapeutic Window ◽  
Left Middle Cerebral Artery ◽  
Significant Past Medical History ◽  
Endovascular Thrombectomy ◽  
Cerebral Artery Occlusion

A 45-year-old patient with no significant past medical history presented to out-patient department with aphasia and right hand weakness with a National Institutes of Health Stroke Scale (NIHSS) of 10 and occlusion of the left middle cerebral artery (MCA) in the M1 segment. Last known normal time was 14hrs (wake up stroke). Immediate endovascular thrombectomy was performed 14 hours after symptom onset with complete recanalization and complete clinical recovery. Although mechanical thrombectomy is generally considered an effective alternative strategy up to 8 hours after stroke onset, selected patients with a large diffusion/perfusion mismatch and small infarct cores may benefit from an expanded therapeutic window.

scholarly journals Insulin and glucagon share the same mechanism of neuroprotection in diabetic rats: role of glutamate

2011 ◽  
Vol 301 (3) ◽  
pp. R668-R673 ◽  
Author(s):  
Rami Abu Fanne ◽  
Taher Nassar ◽  
Samuel N. Heyman ◽  
Nuha Hijazi ◽  
Abd Al-Roof Higazi
Keyword(s):  
Amino Acids ◽  
Neuroprotective Effect ◽  
Artery Occlusion ◽  
Diabetic Rats ◽  
Metabolic Effects ◽  
Therapeutic Window ◽  
Neuroprotective Effects ◽  
Glucose Levels ◽  
Cerebral Artery Occlusion

In patients with acute ischemic stroke, diabetes and hyperglycemia are associated with increased infarct size, more profound neurologic deficits and higher mortality. Notwithstanding extensive clinical and experimental data, treatment of stroke-associated hyperglycemia with insulin is controversial. In addition to hyperglycemia, diabetes and even early prediabetic insulin resistance are associated with increased levels of amino acids, including the neurotoxic glutamate, in the circulation. The pleiotropic metabolic effects of insulin include a reduction in the concentration of amino acids in the circulation. In this article, we show that in diabetic rats exposed to transient middle cerebral artery occlusion, a decrease of plasma glutamate by insulin or glucagon reduces CSF glutamate, improves brain histology, and preserves neurologic function. The neuroprotective effect of insulin and glucagon was similar, notwithstanding their opposite effects on blood glucose. The therapeutic window of both hormones overlapped with the short duration (∼30 min) of elevated brain glutamate following brain trauma in rodents. Similar neuroprotective effects were found after administration of the glutamate scavenger oxaloacetate, which does not affect glucose metabolism. These data indicate that insulin and glucagon exert a neuroprotective effect within a very brief therapeutic window that correlates with their capacity to reduce glutamate, rather than by modifying glucose levels.

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