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1.
ObjectiveMethamphetamine is used extensively around the world as a psychostimulant. The complications related to methamphetamine include methamphetamine-induced neurotoxicity, mainly involving intraneuronal processes, such as oxidative stress and excitotoxicity. Curcumin is effective against neuronal injury due to its antioxidant, anti-inflammatory effects. In this study, we examined the protective effects of curcumin against methamphetamine neurotoxicity.MethodsSixty male Wistar rats were divided into the following groups: control (n = 12), DMSO (n = 12), methamphetamine (n = 12), and methamphetamine + curcumin (100 and 200 mg/kg, respectively, intraperitoneal [IP]; n = 12). Neurotoxicity was induced by 40 mg/kg of methamphetamine administrated through 4 injections (4 × 10 mg/kg, q2h, IP). Curcumin (100 and 200 mg/kg) was administered at 7 days after the last methamphetamine injection. By using a Morris water maze task, the hippocampus-dependent memory and spatial learning were evaluated 1 day after the last curcumin injection. Then, the animal brains were isolated for biochemical measurements, as well as glial fibrillary acidic protein (GFAP), ionized calcium-binding adaptor protein-1(Iba-1) and caspase-3 immunohistochemical staining.ResultsThe current study demonstrated that administration of curcumin significantly attenuates spatial memory impairment (P < 0.01) following methamphetamine neurotoxicity. Curcumin caused a significant increase in the levels of superoxide dismutase and glutathione peroxidase (P < 0.05). However, it decreased tumor necrosis factor (TNF-α) (P < 0.05) and malondialdehyde (P < 0.01) levels as compared to the methamphetamine group. Also, curcumin significantly reduced Iba-1 (P < 0. 01), GFAP and caspase-3 positive cells in the hippocampus (P < 0.001).ConclusionCurcumin exerted neuroprotective effects on methamphetamine neurotoxicity because of its antioxidant and anti-inflammatory effect. 相似文献
2.
Hao Lu Jianvana Hu Jina Li Wei Pancl Yandan Hu Honaoena Yana Weniie Li Chengyu Huang Mingman Zhang Yugang Jiang 《中国神经再生研究》2013,8(29):2754-2762
Zinc supplementation can help maintain learning and memory function in rodents. In this study, we hypothesized that zinc supplementation could antagonize the neurotoxicity induced by aluminum in rats. Animals were fed a diet containing different doses of zinc (50, 100, 200 mg/kg) for 9 weeks, and orally administered aluminum chloride (300 mg/kg daily) from the third week for 7 consecutive weeks. Open-field behavioral test results showed that the number of rearings in the group given the 100 mg/kg zinc supplement was significantly increased compared with the group given the 50 mg/kg zinc supplement. Malondialdehyde content in the cerebrum was significantly decreased, while dopamine and 5-hydroxytryptamine levels were increased in the groups given the diet sup- plemented with 100 and 200 mg/kg zinc, compared with the group given the diet supplemented with 50 mg/kg zinc. The acetylcholinesterase activity in the cerebrum was significantly decreased in the group given the 100 mg/kg zinc supplement. Hematoxylin-eosin staining revealed evident patho- logical damage in the hippocampus of rats in the group given the diet supplemented with 50 mg/kg zinc, but the damage was attenuated in the groups given the diet supplemented with 100 and 200 mg/kg zinc. Our findings suggest that zinc is a potential neuroprotective agent against alumi-num-induced neurotoxicity in rats, and the optimal dosages are 100 and 200 mg/kg. 相似文献
3.
The aim of the study was to demonstrate the therapeutic effect of taurine against aluminum (Al)-induced neurological disorders in rats. Forty-two Wistar rats were randomly allotted into six groups: control (saline only), Al exposure (281.4 mg/kg/day for 1 month), Al + taurine (Al administration as previously plus taurine, doses were 200, 400 and 800 mg/kg/day, respectively, for the next 1 month) and prevention group (along with the Al administration as previously, 400 mg/kg/day taurine was treated for 1 month. During the next 1 month, rats were given taurine 400 mg/kg/day only). Starting from the sixth week, the body weight gain was significantly reduced in Al exposure group compared with saline (P < 0.05), and at the eighth week, the gain in prevention group was increased compared with Al (P < 0.05). Brain coefficient was gained in Al exposure compared with saline or prevention group (P < 0.05). Al exposure resulted in learning and memory impairment by increasing the escape latency and searching distance, meanwhile, decreasing the swimming time in the quadrant of platform and the numbers of crossing the platform (P < 0.05). Unsurprisingly, taurine treatment (400, 800 mg/kg/day and prevention) significantly protected against Al-induced brain dysfunction (P < 0.05). The Al exposure led to significant decreases in levels of γ-GABA and Tau, meanwhile, increased in level of Asp and Glu compared with saline (P < 0.05). And yet, taurine treatment partially reversed the deteriorated changes. The results suggested that taurine probably has neuroprotective effect against Al-induced learning, memory and brain neurotransmitters dysfunction. 相似文献
4.
《Neuropeptides》2021
It has been shown that alcohol consumption by pregnant women can have detrimental effects on the developing fetus and lead to fetal alcohol spectrum disorders (FASD). Exposure to alcohol in rat pups during this period causes long-term changes in the structure of the animal's hippocampus, leading to impaired hippocampal-related brain functions such as navigation tasks and spatial memory. Apelin-13, a principal neuropeptide with inhibitory effects on neuroinflammation and brain oxidative stress production, has beneficial properties on memory impairment and neuronal injury. The protective effects of apelin-13 have been evaluated on ethanol-related neurotoxicity in the hippocampus of rat pups. Rat pups from 2 until 10 postnatal day, similar to the third trimester of pregnancy in humans, were intubated total daily dose of ethanol (5/27 g/kg/day). Immediately after intubation, 25 and 50 μg/ kg of apelin-13 was injected subcutaneously. By using Morris water maze task, the hippocampus- dependent memory and spatial learning were evaluated 36 days after birth. Then, Immunohistochemical staining was done to determine the levels of GFAP and caspase-3. ELISA assay was also performed to measure both TNF-α and antioxidant enzymes levels. The current study demonstrates that administration of apelin-13 attenuates spatial memory impairment significantly (P < 0.001). After ethanol neurotoxicity, apelin-13 could also increase the catalase level (P < 0.001), activity of total superoxide dismutase as well as glutathione concentration noticeably (P < 0.05). Other impacts of it could be mentioned as attenuating TNF-α production and also preventing lipid peroxidation (P < 0.001). In addition, the results showed that the level of GFAP as a neuroinflammation factor and the number of active caspase-3 positive cells can be decreased by apelin-13 (P < 0.01). Regarding the protective effects of apelin-13 against ethanol-induced neurotoxicity, it is a promising therapeutic choice for FASD; but more studies are needed. 相似文献
5.
Lin TY Lu CW Wang CC Wang YC Wang SJ 《Progress in neuro-psychopharmacology & biological psychiatry》2011,35(7):1785-1793
There is abundant evidence suggesting the relevance of glutamate to depression and antidepressant mechanisms. Curcumin, a major active compound of Curcuma longa, has been reported to have the biological function of antidepressant. The aim of the present study was to investigate the effect of curcumin on endogenous glutamate release in nerve terminals of rat prefrontal cortex and the underlying mechanisms. The results showed that curcumin inhibited the release of glutamate that was evoked by exposing synaptosomes to the K+ channel blocker 4-aminopyridine (4-AP). This phenomenon was blocked by the chelating the extracellular Ca2+ ions, and by the vesicular transporter inhibitor bafilomycin A1, but was insensitive to the glutamate transporter inhibitor DL-threo-β-benzyl-oxyaspartate (DL-TBOA). Further experiments demonstrated that curcumin decreased depolarization-induced increase in [Ca2+]C, whereas it did not alter the resting membrane potential or 4-AP-mediated depolarization. Furthermore, the inhibitory effect of curcumin on evoked glutamate release was prevented by blocking the Cav2.2 (N-type) and Cav2.1 (P/Q-type) channels, but not by blocking intracellular Ca2+ release or Na+/Ca2+ exchange. These results suggest that curcumin inhibits evoked glutamate release from rat prefrontocortical synaptosomes by the suppression of presynaptic Cav2.2 and Cav2.1 channels. Additionally, we also found that the inhibitory effect of curcumin on 4-AP-evoked glutamate release was completely abolished by the clinically effective antidepressant fluoxetine. This suggests that curcumin and fluoxetine use a common intracellular mechanism to inhibit glutamate release from rat prefrontal cortex nerve terminals. 相似文献
6.
Arancibia S Silhol M Moulière F Meffre J Höllinger I Maurice T Tapia-Arancibia L 《Neurobiology of disease》2008,31(3):316-326
We examined the potential protective effect of BDNF against beta-amyloid-induced neurotoxicity in vitro and in vivo in rats. In neuronal cultures, BDNF had specific and dose-response protective effects on neuronal toxicity induced by Abeta(1-42) and Abeta(25-35). It completely reversed the toxic action induced by Abeta(1-42) and partially that induced by Abeta(25-35). These effects involved TrkB receptor activation since they were inhibited by K252a. Catalytic BDNF receptors (TrkB.FL) were localized in vitro in cortical neurons (mRNA and protein). In in vivo experiments, Abeta(25-35) was administered into the indusium griseum or the third ventricle and several parameters were measured 7 days later to evaluate potential Abeta(25-35)/BDNF interactions, i.e. local measurement of BDNF release, number of hippocampal hilar cells expressing SRIH mRNA and assessment of the corpus callosum damage (morphological examination, pyknotic nuclei counting and axon labeling with anti-MBP antibody). We conclude that BDNF possesses neuroprotective properties against toxic effects of Abeta peptides. 相似文献
7.
目的:探讨大鼠脑缺血再灌注损伤后,海马CAl区锥体细胞caspaso-3表达及细胞凋亡的变化及使用钾通道拮抗剂IBTX(ibetiotoxin)的保护作用及其保护机制。方法:通过腹腔注射硝普钠加双侧颈总动脉夹闭建立大鼠全脑缺血一再灌模型,侧脑室注射IBTX,免疫组化法测caspase-3表达情况,TUNEL法检测细胞凋亡。结果:大鼠全脑缺血-再灌注24小时后,海马CAl区锥体细胞caspase-3阳性表达,TUNEL法检测有细胞凋亡,在用药IBTX组,caspase-3阳性表达减少,TUNEI法检测细胞凋亡亦有明显降低。结论:大鼠全脑缺血-再灌注24小时后海马CAl区锥体细胞出现细胞凋亡,使用钾通道拮抗剂IBTX可减少细胞凋亡的发生,从而发挥保护作用。 相似文献
8.
Gopalreddygari Visweswari Kanchi Siva Prasad Pandanaboina Sahitya Chetan Valluru Lokanatha Wudayagiri Rajendra 《Epilepsy & behavior : E&B》2010,17(3):332-335
The study described here was carried out to investigate the anticonvulsant effect of different extracts of Centella asiatica with respect to cholinergic activity on pentylenetetrazol (PTZ)-induced seizures. Rats were randomly divided into eight groups of six rats each: nonepileptic rats treated with saline; PTZ (60 mg/kg, IP)-induced seizure rats treated with saline; PTZ-induced seizure rats pretreated with n-hexane, chloroform, ethyl acetate, n-butanol, and water extracts of C. asiatica; and PTZ-induced seizure rats pretreated with diazepam (2 mg/kg body wt). The seized rats pretreated with different extracts were administered a dose of 200 mg/kg body wt orally for 1 week before induction of epilepsy. Increased acetylcholine content and decreased acetylcholinesterase activity were recorded in different brain regions during PTZ-induced seizures. Pretreatment with C. asiatica extracts caused recovery of the levels of acetylcholine and acetylcholinesterase. These findings suggest that C. asiatica causes perceptible changes in the cholinergic system as one of the facets of its anticonvulsant activity. 相似文献
9.
Studies have shown that exercise interventions can improve functional recovery after spinal cord injury, but the mechanism of action remains unclear. To investigate the mechanism, we established a unilateral corticospinal tract injury model in rats by pyramidotomy, and used a single pellet reaching task and horizontal ladder walking task as exercise interventions postoperatively. Functional recovery of forelimbs and forepaws in the rat models was noticeably enhanced after the exercises. Furthermore, TUNEL staining revealed significantly fewer apoptotic cells in the spinal cord of exercised rats, and western blot analysis showed that spinal cord expression of the apoptosis-related protein caspase-3 was significantly lower, and the expression of Bcl-2 was significantly higher, while the expression of Bax was not signifiantly changed after exercise, compared with the non-exercised group. Expression of these proteins decreased with time after injury, towards the levels observed in sham-operated rats, however at 4 weeks postoperatively, caspase-3 expression remained significantly greater than in sham-operated rats. The present findings indicate that a reduction in apoptosis is one of the mechanisms underlying the improvement of functional recovery by exercise interventions after corticospinal tract injury. 相似文献
10.
Rizwana Tabassum Kumar Vaibhav Pallavi Shrivastava Andleeb Khan Md. Ejaz Ahmed Hayate Javed Farah Islam Sayeed Ahmad M. Saeed Siddiqui Mohammed M. Safhi Fakhrul Islam 《Neurological sciences》2013,34(6):925-933
Centella asiatica has been used as psychoactive and antioxidant herbal medicine since ancient time. The present study was design to evaluate the preventive role of ethanolic extract of C. asiatica in middle cerebral artery occlusion (MCAO) in rats. Male Wistar rats were gavaged orally with C. asiatica extract (100, 200 and 300 mg/kg body weight once daily) for 21 days and thereafter subjected to right MCAO for 2 h followed by 22-h reperfusion. Brain injury was evaluated by 2,3,5-triphenyltetrazolium chloride and hematoxylin and eosin staining. Behavioural outcomes as neurological deficit, rota rod test, and grip strength were assessed. In addition, lipid peroxidation, enzymatic and non enzymatic antioxidants were analyzed to assess the oxidative stress. Our results revealed that C. asiatica administration greatly improved neurobehavioral activity and diminished infarction volume along with the restored histological morphology of brain in MCAO rats. Furthermore, supplementation with this extract to MCAO group has reduced the level of thiobarbituric acid reactive species, restored glutathione content and augmented the activities of antioxidant enzymes—catalase, glutathione peroxidase, glutathione reductase, glutathione-S-transferase and superoxide dismutase in a dose-dependent manner in ischemic rats. The remarkable antioxidant activity of C. asiatica may be attributed to its bioactive triterpenes, asiatic acid, asiaticoside, madecassic acid and madecosside and may be translated to clinical level for prevention of ischemic stroke. 相似文献
11.
Hiscock M 《Journal of clinical and experimental neuropsychology》2007,29(5):514-529
Evidence from several nations indicates that performance on mental ability tests is rising from one generation to the next, and that this "Flynn effect" has been operative for more than a century. No satisfactory explanation has been found. Nevertheless, the phenomenon has important implications for clinical utilization of IQ tests. This article summarizes the empirical basis of the Flynn effect, arguments about the nature of the skill that is increasing, and proposed explanations for the cause of the increase. Ramifications for clinical neuropsychology are discussed, and some of the broader implications for psychology and society are noted. 相似文献
12.
Cortical regulation of subcortical dopamine systems and its possible relevance to schizophrenia 总被引:4,自引:0,他引:4
A. A. Grace 《Journal of neural transmission (Vienna, Austria : 1996)》1993,91(2-3):111-134
Summary A unique model of DA system regulation is presented, in which tonic steady-state DA levels in the ECF act to down-regulate the response of the system to pulsatile DA released by DA cell action potential generation. This type of regulation is similar in many respects to the phenomenon proposed to mediate the action of norepinephrine on target neurons; i.e., an increase in the signal-to-noise ratio as measured by postsynaptic cell firing (Freedman et al., 1977; Woodward et al., 1979). However, in this model the signal and the noise are neurochemical rather than electrophysiological. Furthermore, the noise (tonic DA in the ECF) actually down-regulates the signal (phasic DA release) directly, and thereby provides a signal of its own that affects the system over a longer time-course. Therefore, the difference between signal and noise may also depend on the time frame under which such determinations are made. 相似文献
13.
Világi I Takács J Gulyás-Kovács A Banczerowski-Pelyhe I Tarnawa I 《Brain research bulletin》2002,59(1):35-40
2,3-Benzodiazepines represent a family of specific, noncompetitive AMPA receptor antagonists with anticonvulsant and neuroprotective properties. In this study, the antiexcitotoxic potency of the clinical antiepileptic drug candidate, talampanel (4 x 2 mg/kg), and that of two related 2,3-benzodiazepines, 5-(4-aminophenyl)-8-methyl-9H-1,3-dioxolo[4,5-h][2,3]-benzodiazepine (GYKI 52466) (4 x 10 mg/kg) and GYKI 53784 (4 x 2 mg/kg), was investigated in 7-day-old rats. The AMPA antagonists were applied in four consecutive i.p. injections at 1-h intervals, the first dosage was given shortly after the intrastriatal injection of (S)-alpha-amino-3-hydroxy-5,7-methylisoxazole-4-propionic acid (AMPA) (2.5 nmol). All tested compounds protected animals from brain damage induced by AMPA as assessed 5 days later by using a tissue volume determination method based on computer-aided serial section reconstruction. GYKI 53784 (56.1 +/- 5.0% protection) and talampanel (42.5 +/- 5.3% protection) were more potent neuroprotective agents than GYKI 52466 (21.8 +/- 2.8% protection). Furthermore, the three compounds attenuated the unilateral AMPA injection-induced turning behavior and seizure-like events.Our present findings are in agreement with those of other investigators who found talampanel neuroprotective in various in vivo experimental models. These data indicate that besides being a promising antiepileptic drug candidate talampanel may have a value in the pharmacotherapy of acute and chronic neurodegenerative diseases, including perinatal ischemia/hypoxia-induced brain injuries, as well. 相似文献
14.
Therapeutic effect of inosine in Tourette syndrome and its possible mechanism of action 总被引:1,自引:0,他引:1
We found incidentally 3 years ago that inosine relieved the symptoms in a patient with Tourette syndrome. Since then, 36 patients suffered from Tourette syndrome were exclusively treated with inosine, 50-90 mg/kg daily in divided doses. The vocal and non-vocal tic attacks were counted either by the observation of an examiner or with a video-tape record. The clinical status was scored as the sum of the number of various tic attacks recorded during a period of 60 minutes (video-tape record) or 20 minutes (direct observation). According to the scores obtained from double blind cross-over trial (11 cases) and open trial (25 cases), the tic attacks were well controlled in 75% of patients treated. A follow-up study by the end of one year medication the efficacy of inosine was still impressive in 50% of patients. Since we have observed that inosine potentiated the release of dopamine from rat striatal synaptosomes, mimicked the action of some dopamine antagonists, it is suggested that inosine might behave as a dopamine antagonist and exerts its effect on Tourette syndrome as haloperidol does. 相似文献
15.
Despite the increasing popularity of Centella asiatica (a well known plant in ayurvedic medicine) globally, evidence demonstrating its protective efficacy against neurotoxicants in animal models is limited. 3-Nitropropionic acid (3-NPA), a fungal toxin is a well known neurotoxicant which induces selective striatal pathology similar to that seen in Huntington's disease. The present study aimed to understand the neuroprotective efficacy of a standardized aqueous extract of C. asiatica (CA) against 3-NPA-induced early oxidative stress and mitochondrial dysfunctions in striatum and other brain regions. We determined the extent of oxidative stress in cytosol and mitochondria of brain regions of male mice (4 wk old) given CA prophylaxis (5 mg/kg bw) for 10 days followed by 3-NPA administration (i.p., 75 mg/kg bw/d) on the last 2 days. The neurotoxicant elicited marked oxidative stress in the untreated mice as evidenced by elevated levels of malondialdehyde, ROS levels and hydroperoxides in the striatum (cytosol and mitochondria), while CA prophylaxis completely attenuated the 3-NPA-induced oxidative stress. 3-NPA also caused significant oxidative stress and protein oxidation in cytosol/mitochondria of other brain regions as well which were predominantly abolished by CA prophylaxis. Significant depletion of GSH levels, total thiols and perturbations in antioxidant enzymic defences in striatum and other brain regions discernible among 3-NPA administered mice were also protected with CA prophylaxis. Interestingly, CA prophylaxis offered varying degree of protection against 3-NPA-induced mitochondrial dysfunctions viz., reduction in the activity of succinic dehydrogenase, ETC enzymes and decreased mitochondrial viability. Collectively these findings clearly suggest that short-term oral intake of a standardized aqueous extract of CA confers marked resistance against the 3-NPA-induced oxidative stress and mitochondrial dysfunctions in brain. Although the precise mechanism/s underlying the prophylactic efficacy of CA merit further investigation, based on these findings, it is hypothesized that it may be wholly or in part related to the enhancement of GSH, thiols and antioxidant machinery in the brain regions of prepubertal mice. 相似文献
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17.
Mehdi Goudarzi Mohammad Amin Mombeini Iman Fatemi Azadeh Aminzadeh Heibatullah Kalantari Ali Nesari 《Neurological research》2013,35(5):419-428
ABSTRACTAcrylamide (ACR) is an environmental contaminant and a well-known neurotoxin. Ellagic acid (EA), a natural plant polyphenol, has shown a variety of beneficial effects. The present study was designed to explore whether EA could attenuate ACR-induced neurotoxicity in rats and to explore the underlying mechanisms. Animals were divided into five groups. Group 1 was treated with normal saline (2 mL/kg) for 30 days. Group 2 was treated with ACR (20 mg/kg, orally) for 30 days. Groups 3 and 4 were treated with ACR and EA (10 and 30 mg/kg, orally) for 30 days. Group 5 was treated with EA (30 mg/kg, orally) for 30 days. Open field, rotarod and passive avoidance test were conducted to evaluate behavioral changes, respectively. The brain cortex was used for histological examination. Different oxidative parameters and inflammatory biomarkers were assessed in the brain cortex. ACR-administered rats showed a considerable impairment in exploratory behavior, motor performance as well as cognition. Our data also showed that ACR administration significantly increases malondialdehyde, nitric oxide, interleukin-1β and tumor necrosis factor-α levels. Moreover, it decreases brain glutathione level, superoxide dismutase, glutathione peroxidase, catalase activity. Co-administration of EA (especially 30 mg/kg, p.o.) prevented these changes; however, it did not affect the glutathione peroxidase activity. These results were supported by histopathological observations of the brain. Our results suggest that EA can be useful for protecting brain tissue against ACR-induced neurotoxicity through ameliorative effects on inflammatory indices and oxidative stress parameters. 相似文献
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Harkany T Hortobágyi T Sasvári M Kónya C Penke B Luiten PG Nyakas C 《Progress in neuro-psychopharmacology & biological psychiatry》1999,23(6):963-1008
1. beta-Amyloid peptides (A beta s) accumulate abundantly in the Alzheimer's disease (AD) brain in areas subserving information acquisition and processing, and memory formation. A beta fragments are produced in a process of abnormal proteolytic cleavage of their precursor, the amyloid precursor protein (APP). While conflicting data exist in the literature on the roles of A beta s in the brain, and particularly in AD, recent studies have provided firm experimental evidence for the direct neurotoxic properties of A beta. 2. Sequence analysis of A beta s revealed a high degree of evolutionary conservation and inter-species homology of the A beta amino acid sequence. In contrast, synthetic A beta fragments, even if modified fluorescent or isotope-labeled derivatives, are pharmacological candidates for in vitro and in vivo modeling of their cellular actions. During the past decade, acute injection, prolonged mini-osmotic brain perfusion approaches or A beta infusions into the blood circulation were developed in order to investigate the effects of synthetic A beta s, whereas transgenic models provided insight into the distinct molecular steps of pathological APP cleavage. 3. The hippocampus, caudate putamen, amygdala and neocortex all formed primary targets of acute neurotoxicity screening, but functional consequences of A beta infusions were primarily demonstrated following either intracerebroventricular or basal forebrain (medial septum or magnocellular basal nucleus (MBN)) infusions of A beta fragments. 4. In vivo investigations confirmed that, while the active core of A beta is located within the beta(25-35) sequence, the flanking peptide regions influence not only the folding properties of the A beta fragments, but also their in vivo neurotoxic potentials. 5. It has recently been established that A beta administration deranges neuron-glia signaling, affects the glial glutamate uptake and thereby induces noxious glutamatergic stimulation of nerve cells. In fact, a critical role for N-methyl-D-aspartate (NMDA) receptors was postulated in the neurotoxic processes. Additionally, A beta s might become internalized, either after their selective binding to cell-surface receptors or after membrane association in consequence of their highly lipophilic nature, and induce free radical generation and subsequent oxidative injury. Ca(2+)-mediated neurotoxic events and generation of oxygen free radicals may indeed potentiate each other, or even converge to the same neurotoxic events, leading to cell death. 6. Neuroprotection against A beta toxicity was achieved by both pre- and post-treatment with NMDA receptor channel antagonists. Moreover, direct radical-scavengers, such as vitamin E or vitamin C, attenuated A beta toxicity with high efficacy. Interestingly, combined drug treatments did not necessarily result in additive enhanced neuroprotection. 7. Similarly to the blockade of NMDA receptors, the neurotoxic action of A beta s could be markedly decreased by pharmacological manipulation of voltage-dependent Ca(2+)-channels, serotonergic IA or adenosine A1 receptors, and by drugs eliciting membrane hyperpolarization or indirect blockade of Ca(2+)-mediated intracellular consequences of intracerebral A beta infusions. 8. A beta neurotoxicity might be dose-dependently modulated by trace metals. In spite of the fact that zinc (Zn) may act as a potent inhibitor of the NMDA receptor channel, high Zn doses accelerate A beta fibril formation, stabilize the beta-sheet conformation and thereby potentiate A beta neurotoxicity. Combined trace element supplementation with Se, Mn, or Mg, which prevails over the expression of detoxifying enzymes or counteracts intracellular elevations of Ca2+, may reduce the neurotoxic impact of A beta s. 9. Alterations in the regulatory functions of the hypothalamo-pituitary-adrenal axis may contribute significantly to neurodegenerative changes in the brain. Furthermore, AD patients exhibit substantially increased circadia 相似文献
20.
目的探讨褪黑素对脑出血(ICH)后大鼠脑组织神经细胞超微结构、氧化应激及促炎症因子表达的影响及机制。方法 SD大鼠130只随机分为正常组、假手术组、ICH模型组(模型组)、褪黑素干预组(褪黑素组),除正常组外,各组随机分为12 h、1 d、2 d、4 d、7 d共5个时间点亚组;采用透射电镜技术观察神经细胞超微结构;黄嘌呤氧化法和硫代巴比妥酸比色法测定脑组织超氧化物岐化酶(SOD)活性、丙二醛(MDA)含量;免疫组化法检测核转录因子-κB(NF-κB)p65阳性细胞表达;Western blot法检测肿瘤坏死因子-α(TNF-α)蛋白表达。结果 ICH后模型组神经元肿胀、核膜结构不清、细胞器减少,线粒体肿胀、空泡化,可见类似凋亡的细胞核,同一时间点褪黑素组神经元及线粒体超微结构病理改变轻微。与正常组和假手术组比较,模型组ICH后12 h~4 d时SOD活性明显降低,MDA含量明显升高(均P0.05);与模型组比较,褪黑素组MDA含量显著降低,SOD活性升高(均P0.05);ICH后模型组NF-κBp65阳性细胞表达和TNF-α蛋白表达高于正常组(均P0.05)。ICH后不同时间点褪黑素组NF-κB p65阳性细胞及TNF-α蛋白表达水平显著低于模型组(均P0.05)。结论褪黑素可减轻ICH大鼠神经细胞超微结构损伤及氧化应激水平,褪黑素的神经保护机制可能与其抑制ICH后炎症反应相关。 相似文献