scholarly journals Neuroprotective Effects of Early Hypothermia Induced by Phenothiazines and DHC in Ischemic Stroke

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Yun Han ◽  
Xiao-kun Geng ◽  
Hangil Lee ◽  
Fengwu Li ◽  
Yuchuan Ding
Keyword(s):  
Ischemic Stroke ◽  
Brain Damage ◽  
Glucose Transporter ◽  
Infarct Volume ◽  
Neurological Deficits ◽  
Ros Production ◽  
Sprague Dawley ◽  
Drug Induced ◽  
Neuroprotective Effects ◽  
Sprague Dawley Rats

Background and Purpose. Studies have shown that interischemia hypothermia is able to reduce the size of myocardial infarctions and improve their clinical outcomes. The present study determined whether interischemia hypothermia induced by the pharmacological approach induced stronger neuroprotection in ischemic brains. Methods. Adult male Sprague Dawley rats were studied in 4 groups: (1) sham; (2) stroke; (3) stroke treated with pharmacological hypothermia before reperfusion (interischemia hypothermia); and (4) stroke treated with pharmacological hypothermia after reperfusion is initiated (inter-reperfusion hypothermia). The combination of chlorpromazine and promethazine with dihydrocapsaicin (DHC) was used to induce hypothermia. To compare the neuroprotective effects of drug-induced hypothermia between the interischemia and inter-reperfusion groups, brain damage was evaluated using infarct volume and neurological deficits at 24 h reperfusion. In addition, mRNA expressions of NADPH oxidase (NOX) subunits (gp91phox, p67phox, p47phox, and p22phox) and glucose transporter subtypes (GLUT1 and GLUT3) were determined by real-time PCR at 6 and 24 h reperfusion. ROS production was measured by flow cytometry assay at the same time points. Results. In both hypothermia groups, the cerebral infarct volumes and neurological deficits were reduced in the ischemic rats. At 6 and 24 h reperfusion, ROS production and the expressions of NOX subunits and glucose transporter subtypes were also significantly reduced in both hypothermia groups as compared to the ischemic group. While there were no statistically significant differences between the two hypothermia groups at 6 h reperfusion, brain damage was significantly further decreased by interischemia hypothermia at 24 h. Conclusion. Both interischemia and inter-reperfusion pharmacological hypothermia treatments play a role in neuroprotection after stroke. Interischemia hypothermia treatment may be better able to induce stronger neuroprotection after ischemic stroke. This study provides a new avenue and reference for stronger neuroprotective hypothermia before vascular recanalization in stroke patients.

scholarly journals Mito-Tempo prevents nicotine-induced exacerbation of ischemic brain damage

2018 ◽  
Vol 125 (1) ◽  
pp. 49-57 ◽  
Author(s):  
Chun Li ◽  
Hong Sun ◽  
Guodong Xu ◽  
Kimberly D. McCarter ◽  
Jiyu Li ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Brain Damage ◽  
Focal Cerebral Ischemia ◽  
Infarct Volume ◽  
Neutrophil Infiltration ◽  
Neurological Deficits ◽  
Sprague Dawley ◽  
Ischemic Brain Damage ◽  
Mitochondrial Oxidative Stress ◽  
Ischemic Brain

Nicotine may contribute to the pathogenesis of cerebrovascular disease via the generation of reactive oxygen species (ROS). Overproduction of ROS leads to brain damage by intensifying postischemic inflammation. Our goal was to determine the effect of Mito-Tempo, a mitochondria-targeted antioxidant, on ischemic brain damage and postischemic inflammation during chronic exposure to nicotine. Male Sprague-Dawley rats were divided into four groups: control, nicotine, Mito-Tempo-treated control, and Mito-Tempo-treated nicotine. Nicotine (2 mg·kg−1·day−1) was administered via an osmotic minipump for 4 wk. Mito-Tempo (0.7 mg·kg−1·day−1ip) was given for 7 days before cerebral ischemia. Transient focal cerebral ischemia was induced by occlusion of the middle cerebral artery for 2 h. Brain damage and inflammation were evaluated after 24 h of reperfusion by measuring infarct volume, expression of adhesion molecules, activity of matrix metalloproteinase, brain edema, microglial activation, and neutrophil infiltration. Nicotine exacerbated infarct volume and worsened neurological deficits. Nicotine did not alter baseline ICAM-1 expression, matrix metallopeptidase-2 activity, microglia activation, or neutrophil infiltration but increased these parameters after cerebral ischemia. Mito-Tempo did not have an effect in control rats but prevented the chronic nicotine-induced augmentation of ischemic brain damage and postischemic inflammation. We suggest that nicotine increases brain damage following cerebral ischemia via an increase in mitochondrial oxidative stress, which, in turn, contributes to postischemic inflammation.NEW & NOTEWORTHY Our findings have important implications for the understanding of mechanisms contributing to increased susceptibility of the brain to damage in smokers and users of nicotine-containing tobacco products.

Abstract WP315: Neuroprotective Effects of Endogenous Adropin in Experimental Ischemic Stroke

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Changjun Yang ◽  
Brian D Sanz ◽  
Kelly M DeMars ◽  
Andrew A Butler ◽  
Eduardo Candelario-Jalil
Keyword(s):  
Ischemic Stroke ◽  
Brain Damage ◽  
Energy Homeostasis ◽  
Infarct Volume ◽  
Protective Effects ◽  
Neuroprotective Effects ◽  
Ischemic Brain Damage ◽  
Ischemic Brain ◽  
Male And Female ◽  
Enos Phosphorylation

Adropin is an endogenous peptide highly expressed in the brain and is encoded by the energy homeostasis-associated gene, Enho . We recently found that treatment with synthetic adropin peptide reduces infarct volume in ischemic stroke. This protection by exogenous adropin is associated with a significant increase in endothelial nitric oxide synthase (eNOS) phosphorylation (Ser 1176 ) and reduction of blood-brain barrier (BBB) permeability. However, it is not known whether endogenous adropin modulates ischemic brain damage. We hypothesize that lack of brain adropin increases stroke damage by exacerbating neurovascular dysfunction, while overexpression of this peptide decreases ischemic brain injury. We measured infarct size and BBB damage in male and female adropin overexpressing transgenics (AdrTg), adropin knockout ( Enho -/- ), and corresponding wild-type (WT) control mice subjected to permanent middle cerebral artery occlusion (pMCAO). At 48h after stroke, infarct volume was significantly smaller in AdrTg mice of both sexes compared to WT controls, while stroke resulted in a much larger infarction in both male and female Enho -/- compared to Enho +/+ mice. Brain levels of IgG and albumin, two sensitive markers of BBB disruption, were significantly reduced in AdrTg mice compared to the WT group, while the levels of these two plasma proteins in the ischemic brain of Enho -/- mice were dramatically increased compared to Enho +/+ animals after stroke. Latex vessel casting showed no differences in cerebrovascular anatomy or the diameter of the main brain arteries between Enho -/- , AdrTg and their respective WT controls. In AdrTg mice, we found a positive correlation between brain adropin levels and eNOS phosphorylation. These data suggest that increased eNOS phosphorylation by adropin is a potential mechanism underlying its protective effects in stroke. Consistent with this hypothesis, the protective effects of adropin were completely abolished in eNOS knockout (eNOS -/- ) mice subjected to pMCAO. Taken together, our findings show for the first time that endogenous adropin is a neuroprotective peptide in ischemic stroke. Understanding adropin signaling and function could offer a novel therapeutic strategy for the treatment of ischemic brain damage.

Abstract WP79: Appropriate Timing of Fluoxetine and Statin Administration Reduces the Risk of Secondary Hemorrhagic Infarct After Ischemic Stroke

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Moner A Ragas ◽  
Maria H Balch ◽  
Danny Wright ◽  
Amber Hensley ◽  
Kenny Reynolds ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Ischemic Stroke ◽  
Infarct Volume ◽  
Stroke Onset ◽  
Sprague Dawley ◽  
Stroke Patients ◽  
Unequal Variances ◽  
Exact Test ◽  
Strong Trend ◽  
Sprague Dawley Rats

Introduction: Ongoing clinical trials are testing the effect of fluoxetine delivered 2-15 days from the onset of an acute ischemic stroke where a majority of patients are taking statins. We hypothesized that earlier drug delivery would result in smaller infarcts. Methods: Endothelin-1-induced strokes were initiated in 10-12 month old Sprague-Dawley rats, targeting the forelimb motor cortex. Combined medications of 5 mg/kg fluoxetine and 1 mg/kg simvastatin were orally administered either beginning 6-12 hours or 20-26 hours after stroke induction and continued daily for 90 days. Infarct volumes were assessed at post-stroke day 91 using Nissl stained coronal brain sections. An unpaired T-test with Welch’s correction for unequal variances was used for statistical comparison of the infarct volumes. Results: Control animals typically had 5-13 mm3 infarct volumes. Animals that received fluoxetine and simvastatin beginning 20-26 hours after stroke induction showed a strong trend of reduced infarct volume (3 ± 0.3447 mm3 SEM, P=0.0563). Earlier drug delivery (6-12 hours after stroke) resulted in significantly larger infarct volumes (15.4 ± 4.260 mm3 SEM, P=0.0157) when the drug groups were directly compared (Fig.1). Examination of the infarct volumes showed that earlier drug delivery induced secondary hemorrhagic infarcts, while later delivery did not (P=0.0427; Fisher’s exact test). Conclusions: There appears to be substantial danger of developing hemorrhagic infarct if the combination of fluoxetine and statin is given within 6-12 hours of stroke induction (RR= 4.36, 95% CI = 0.64-29.5). For that reason, it is crucial to monitor stroke patients for statins and fluoxetine, and withhold the statin for at least 20 hours after stroke onset. Delivery of both drugs after 20-26 hours of stroke onset resulted in significantly reduced infarcts.

Neuroprotective Effects of Magnesium Lithospermate B against Subarachnoid Hemorrhage in Rats

2018 ◽  
Vol 46 (06) ◽  
pp. 1225-1241 ◽  
Author(s):  
Yucong Peng ◽  
Pingyou He ◽  
Linfeng Fan ◽  
Hangzhe Xu ◽  
Jianru Li ◽  
...  
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Salvia Miltiorrhiza ◽  
Neurological Deficits ◽  
Sprague Dawley ◽  
Chinese Medicinal Herb ◽  
Neuroprotective Effects ◽  
Sprague Dawley Rats ◽  
Apoptotic Protein ◽  
Magnesium Lithospermate B

Subarachnoid hemorrhage (SAH) is a severe cerebrovascular disease with few effective pharmacotherapies available. Salvia miltiorrhiza, a traditional Chinese medicinal herb, has been widely used to treat cardiovascular diseases for centuries. Recent studies have demonstrated that magnesium lithospermate B (MLB), a bioactive ingredient extracted from Salvia miltiorrhiza, exerts neuroprotective effects in several central nervous system insults. However, little is known about the role of MLB in SAH-induced brain injury and the exact molecular mechanism. In the current study, we studied the neuroprotective effects of MLB in SAH and explored the potential mechanism. Adult male Sprague–Dawley rats were subjected to an endovascular perforation process to produce an SAH model. MLB was administrated intraperitoneally at 30[Formula: see text]min after SAH with a dose of 25[Formula: see text]mg/kg or 50[Formula: see text]mg/kg. We found that administration of MLB significantly attenuated brain edema and neurological deficits after SAH. In addition, immunofluorescence staining demonstrated that MLB dose-dependently inhibited the activation of microglia and reduced neuronal apoptosis. Western blot analysis showed that MLB decreased the expression of inflammatory cytokine TNF-[Formula: see text] and pro-apoptotic protein cleaved caspase-3. More importantly, MLB increased the expression of SIRT1, while inhibited the acetylation of NF-[Formula: see text]B. Furthermore, pretreatment with sirtinol (a selective inhibitor of SIRT1) reversed all the aforementioned effects of MLB after SAH. In conclusion, our results indicated that MLB exerted robust neuroprotective effects against SAH via suppressing neuroinflammation and apoptosis. These neuroprotective effects of MLB against SAH might be exerted via regulating the SIRT1/NF-[Formula: see text]B pathway. MLB or the SIRT1/NF-[Formula: see text]B pathway could be a novel and promising therapeutic strategy for SAH management.

scholarly journals Glibenclamide Administration Attenuates Infarct Volume, Hemispheric Swelling, and Functional Impairments following Permanent Focal Cerebral Ischemia in Rats

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Bushra Wali ◽  
Tauheed Ishrat ◽  
Fahim Atif ◽  
Fang Hua ◽  
Donald G. Stein ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Grip Strength ◽  
Focal Cerebral Ischemia ◽  
Infarct Volume ◽  
Artery Occlusion ◽  
Constant Infusion ◽  
Lesion Volume ◽  
Functional Impairments ◽  
Sprague Dawley ◽  
Neuroprotective Effects

Studies from a single laboratory have shown that in rodent models of permanent stroke, administration of the sulfonylurea glibenclamide (Glib) is highly effective in reducing edema, mortality, and lesion volume. The Stroke Therapy Academic Industry Roundtable (STAIR) recommends that new acute treatments for ischemic stroke to be replicated across different laboratories. Accordingly, we examined the effect of low-dose Glib in a permanent suture occlusion model of stroke. Male Sprague-Dawley rats underwent permanent middle cerebral artery occlusion (pMCAO) followed by an initial intraperitoneal injection of Glib (10 μg/kg) and the start of a constant infusion (200 ng/h) via miniosmotic pump at the onset of ischemia. Functional deficits were assessed by Neurological Severity Score (NSS) and grip-strength meter at 24 and 48 h after pMCAO. Glib-treated rats showed a significant reduction in infarct volume, lower NSS, and less hemispheric swelling compared to vehicle. Grip strength was decreased significantly in pMCAO rats compared to shams and significantly improved by treatment with Glib. Taken together, these data indicate that Glib has strong neuroprotective effects following ischemic stroke and may warrant further testing in future clinical trials for human stroke.

Early Development of Drug-Induced Hepatic Necrosis

1971 ◽  
Vol 29 ◽  
pp. 576-577
Author(s):  
F. G. Zaki ◽  
E. Detzi ◽  
C. H. Keysser
Keyword(s):  
Early Development ◽  
Hepatic Necrosis ◽  
Screening Tests ◽  
Dense Matrix ◽  
Sprague Dawley ◽  
Electron Microscopic ◽  
Drug Induced ◽  
Hepatocellular Damage ◽  
Sprague Dawley Rats ◽  
Microscopic Studies

This study represents the first in a series of investigations carried out to elucidate the mechanism(s) of early hepatocellular damage induced by drugs and other related compounds. During screening tests of CNS-active compounds in rats, it has been found that daily oral administration of one of these compounds at a dose level of 40 mg. per kg. of body weight induced diffuse massive hepatic necrosis within 7 weeks in Charles River Sprague Dawley rats of both sexes. Partial hepatectomy enhanced the development of this peculiar type of necrosis (3 weeks instead of 7) while treatment with phenobarbital prior to the administration of the drug delayed the appearance of necrosis but did not reduce its severity.Electron microscopic studies revealed that early development of this liver injury (2 days after the administration of the drug) appeared in the form of small dark osmiophilic vesicles located around the bile canaliculi of all hepatocytes (Fig. 1). These structures differed from the regular microbodies or the pericanalicular multivesicular bodies. They first appeared regularly rounded with electron dense matrix bound with a single membrane. After one week on the drug, these vesicles appeared vacuolated and resembled autophagosomes which soon developed whorls of concentric lamellae or cisterns characteristic of lysosomes (Fig. 2). These lysosomes were found, later on, scattered all over the hepatocytes.

scholarly journals Remote Ischemic Postconditioning vs. Physical Exercise After Stroke: an Alternative Rehabilitation Strategy?

2021 ◽  
Author(s):  
Xiaokun Geng ◽  
Qingzhu Wang ◽  
Hangil Lee ◽  
Christian Huber ◽  
Melissa Wills ◽  
...  
Keyword(s):  
Physical Exercise ◽  
Treadmill Exercise ◽  
Infarct Volume ◽  
Ischemic Postconditioning ◽  
Synaptic Proteins ◽  
Neurological Deficits ◽  
Sprague Dawley ◽  
Neurobehavioral Function ◽  
Remote Ischemic Postconditioning ◽  
Function Tests

AbstractThere remain debates on neuroprotection and rehabilitation techniques for acute ischemic stroke patients. Therapeutic physical exercise following stroke has shown promise but is challenging to apply clinically. Ischemic conditioning, which has several clinical advantages, is a potential neuroprotective method for stroke rehabilitation that is less understood. In the present study, the rehabilitative properties and mechanisms of physical exercise and remote ischemic postconditioning (RIPostC) after stroke were compared and determined. A total of 248 adult male Sprague-Dawley rats were divided into five groups: (1) sham, (2) stroke, (3) stroke with intense treadmill exercise, (4) stroke with mild treadmill exercise, and (5) stroke with RIPostC. Focal ischemia was evaluated by infarct volume and neurological deficit. Long-term functional outcomes were represented through neurobehavioral function tests: adhesive removal, beam balance, forelimb placing, grid walk, rota-rod, and Morris water maze. To further understand the mechanisms underlying neurorehabilitation and verify the presence thereof, we measured mRNA and protein levels of neuroplasticity factors, synaptic proteins, angiogenesis factors, and regulation molecules, including HIF-1α, BDNF, TrkB, and CREB. The key role of HIF-1α was elucidated by using the inhibitor, YC-1. Both exercise intensities and RIPostC significantly decreased infarct volumes and neurological deficits and outperformed the stroke group in the neurobehavioral function tests. All treatment groups showed significant increases in mRNA and protein expression levels of the target molecules for neurogenesis, synaptogenesis, and angiogenesis, with intermittent further increases in the RIPostC group. HIF-1α inhibition nullified most beneficial effects and indicative molecule expressions, including HIF-1α, BDNF, TrkB, and CREB, in both procedures. RIPostC is equally, or superiorly, effective in inducing neuroprotection and rehabilitation compared to exercise in ischemic rats. HIF-1α likely plays an important role in the efficacy of neuroplasticity conditioning, possibly through HIF-1α/BDNF/TrkB/CREB regulation.

Ageing-induced decrease in cardiac mitochondrial function in healthy rats

2013 ◽  
Vol 91 (8) ◽  
pp. 593-600 ◽  
Author(s):  
Oana M. Duicu ◽  
Silvia N. Mirica ◽  
Dorina E. Gheorgheosu ◽  
Andreea I. Privistirescu ◽  
Ovidiu Fira-Mladinescu ◽  
...  
Keyword(s):  
Mitochondrial Function ◽  
Complex I ◽  
Mitochondrial Permeability Transition ◽  
Permeability Transition ◽  
Heart Mitochondria ◽  
Ros Production ◽  
Sprague Dawley ◽  
Retention Capacity ◽  
Mptp Opening ◽  
Sprague Dawley Rats

It is widely recognized that mitochondrial dysfunction is a key component of the multifactorial process of ageing. The effects of age on individual components of mitochondrial function vary across species and strains. In this study we investigated the oxygen consumption, the mitochondrial membrane potential (Δψ), the sensitivity of mitochondrial permeability transition pore (mPTP) to calcium overload, and the production of reactive oxygen species (ROS) in heart mitochondria isolated from old compared with adult healthy Sprague–Dawley rats. Respirometry studies and Δψ measurements were performed with an Oxygraph-2k equipped with a tetraphenylphosphonium electrode. ROS production and calcium retention capacity were measured spectrofluorimetrically. Our results show an important decline for all bioenergetic parameters for both complex I and complex II supported-respiration, a decreased Δψ in mitochondria energized with complex I substrates, and an increased mitochondrial ROS production in the old compared with the adult group. Mitochondrial sensitivity to Ca2+-induced mPTP opening was also increased in the old compared with the adult animals. Moreover, the protective effect of cyclosporine A on mPTP opening was significantly reduced in the old group. We conclude that healthy ageing is associated with a decrease in heart mitochondria function in Sprague–Dawley rats.

scholarly journals Ceftriaxone therapy attenuates brain trauma in rats by affecting glutamate transporters and neuroinflammation and not by its antibacterial effects

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Sher-Wei Lim ◽  
Hui-Chen Su ◽  
Tee-Tau Eric Nyam ◽  
Chung-Ching Chio ◽  
Jinn-Rung Kuo ◽  
...  
Keyword(s):  
Neuronal Apoptosis ◽  
Infarct Volume ◽  
Neuroprotective Effect ◽  
Body Weight Loss ◽  
Motor Dysfunction ◽  
Vehicle Group ◽  
Sprague Dawley ◽  
Antibacterial Effects ◽  
Neuroprotective Effects ◽  
Tnf Α

Abstract Background Ceftriaxone is a β-lactam antibiotic used to treat central nervous system infections. Whether the neuroprotective effects of ceftriaxone after TBI are mediated by attenuating neuroinflammation but not its antibacterial actions is not well established. Methods Anesthetized male Sprague–Dawley rats were divided into sham-operated, TBI + vehicle, and TBI + ceftriaxone groups. Ceftriaxone was intraperitoneally injected at 0, 24, and 48 h with 50 or 250 mg/kg/day after TBI. During the first 120 min after TBI, we continuously measured heart rate, arterial pressure, intracranial pressure (ICP), and cerebral perfusion pressure. The infarct volume was measured by TTC staining. Motor function was measured using the inclined plane. Glutamate transporter 1 (GLT-1), neuronal apoptosis and TNF-α expression in the perilesioned cortex were investigated using an immunofluorescence assay. Bacterial evaluation was performed by Brown and Brenn’s Gram staining. These parameters above were measured at 72 h after TBI. Results Compared with the TBI + vehicle group, the TBI + ceftriaxone 250 mg/kg group showed significantly lower ICP, improved motor dysfunction, reduced body weight loss, decreased infarct volume and neuronal apoptosis, decreased TBI-induced microglial activation and TNF-α expression in microglia, and increased GLT-1 expression in neurons and microglia. However, the grades of histopathological changes of antibacterial effects are zero. Conclusions The intraperitoneal injection of ceftriaxone with 250 mg/kg/day for three days may attenuate TBI by increasing GLT-1 expression and reducing neuroinflammation and neuronal apoptosis, thereby resulting in an improvement in functional outcomes, and this neuroprotective effect is not related to its antibacterial effects.

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