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Results 201 - 250 of 1836
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Isaeva Elena - - 2010
Polysialic acids are widely distributed in neuronal tissue. Due to their position on glycoproteins and gangliosides on the outer cell membranes and anionic nature, polysialic acids are involved in multiple cell signaling events. The level of sialylation of the cellular surface is regulated by endogenous neuraminidase (NEU), which catalyses the ...
Sathyasaikumar Korrapati V - - 2011
The levels of kynurenic acid (KYNA), an astrocyte-derived metabolite of the branched kynurenine pathway (KP) of tryptophan degradation and antagonist of α7 nicotinic acetylcholine and N-methyl-D-aspartate receptors, are elevated in the prefrontal cortex (PFC) of individuals with schizophrenia (SZ). Because endogenous KYNA modulates extracellular glutamate and acetylcholine levels in the ...
Queiroz Edson Alexandre - - 2011
The present study investigated the role of the dorsomedial hypothalamus (DMH) on cardiovascular and behavioural responses of chemoreflex activation in conscious rats. The arterial chemoreflex was activated by potassium cyanide (KCN, 40 μg, i.v.) before and after bilateral microinjection of lidocaine (2%) or kynurenic acid (2.7 nmol) into the DMH. ...
Kalonia H - - 2010
The present study has been designed to explore the protective effect of montelukast (leukotriene receptor antagonist) against intrastriatal quinolinic acid (QA; 300 nmol) and malonic acid (MA; 6 μmol) induced Huntington's like symptoms in rats. Quinolinic acid has been reported to induce excitotoxicity by stimulating the N-methyl-D-aspartate receptor, causing calcium ...
Ohnuma Tohru - - 2011
Hypo-function of N-methyl d-aspartate (NMDA) receptors is strongly involved in the brain pathophysiology of schizophrenia. Several excitatory amino acids, such as endogenous glutamate, glycine, serine and alanine, which are involved in glutamate neurotransmission via NMDA receptors, were studied to further understand the pathophysiology of schizophrenia and to find a biological ...
Puri Puja K - - 2010
We aim to report that skin biopsy, a non-invasive test by neurological standards, may lead to a diagnosis. A 4-year-old male presented with a 2-year history of epilepsy and progressive developmental regression. The patient had a mildly elevated ammonia level; however, evaluation for the accumulation of excess serum amino acids ...
Kusama-Eguchi Kuniko - - 2011
Neurolathyrism is a motor neuron disease caused by the overconsumption of grass pea (Lathyrus sativus L.) containing l-β-ODAP. The precise mechanism to cause motor neuron degeneration has yet to be elucidated, but should agree with the epidemiological backgrounds. Considering the amino acid content of the legume, and the epidemiological link ...
Turunc Ezgi - - 2010
The aim of this study was to investigate the effect of gamma-glutamylcysteine ethylester (GCEE), a precursor of glutathione biosynthesis, on the levels of glutathione, formation of reactive oxygen species and c-fos mRNA expression in rat hippocampus and cortex in kainic acid-induced excitotoxicity. Sprague-Dawley rats were used and divided into four ...
Cao Bi-Yin - - 2010
Paeoniflorin (PF) is the principal bioactive component of Radix Paeoniae alba, which is widely used in Traditional Chinese Medicine for the treatment of neurodegenerative disorders such as Parkinson's disease (PD). To evaluate the neuroprotective effects of PF on MPP(+)- or acid- (pH 5.0) induced injury in cultured PC12 cells and ...
Tomiya Masayuki - - 2010
The levels of kynurenic acid, an endogenous antagonist of alpha(7) nicotinic acetylcholine and N-methyl-D-aspartate receptors, were measured in microdialysis samples obtained from the prefrontal cortices of rats using column-switching high-performance liquid chromatography with fluorescence detection. When the perfusate was constantly infused at a rate of 1.0 mu/min, the in vitro ...
Vermoesen Katia - - 2010
In the present study the effectiveness of different diazepam-ketamine combinations to control kainic acid-induced status epilepticus in rats was evaluated. We show that electrographic monitoring is mandatory to enable reliable assessment of status epilepticus control as the number of false positives is extremely high when status epilepticus control is only ...
Adams Monica L - - 2010
PEGylated poly(carboxylic acid)s, PEG-b-PCAs, were evaluated as additives for solubilized oral formulations of weakly acidic compounds. Micelles of poly(ethylene glycol)-block-poly(acrylic acid), PEG-b-PAA, and poly(ethylene glycol)-block-poly(methacrylic acid), PEG-b-PMAA, were prepared. Fluorescence spectroscopy and dynamic light scattering revealed that both polymers assemble into nanoscopic structures (< 200 nm) in acidic media and exhibit ...
Freitas R M - - 2010
Systemic injection of pilocarpine has been shown to induce recurrent seizures and epileptic discharges demonstrated by EEG monitoring. It also has been reported that antioxidants are able to diminish or prevent the occurrence of epileptic discharges induced by pilocarpine through the inhibition of free radical formation and neurotransmitter metabolic alterations. ...
Maciejak Piotr - - 2010
The results showed that the development of seizures (pentylenetetrazole, PTZ-induced kindling; PTZ was administered to rats at a subconvulsive dose of 35mg/kg three times a week, i.p.) was accompanied by a progressive recruitment of limbic structures and a characteristic pattern of changes in the brain tissue concentration of examined amino ...
Oka Saori - - 2010
GPR35 is a rhodopsin-like G protein-coupled receptor identified in 1998. It has been reported that kynurenic acid, a tryptophan metabolite, may act as an endogenous ligand for GPR35. However, the concentrations of kynurenic acid required to elicit the cellular responses are usually high, raising the possibility that another endogenous ligand ...
Errico Francesco - - 2011
Until recently, free d-amino acids were thought to be involved only in bacterial physiology. Nevertheless, today there is evidence that d-serine, by acting as co-agonist at NMDARs, plays a role in controlling neuronal functions in mammals. Besides d-serine, another d-amino acid, d-aspartate (d-Asp), is found in the mammalian brain with ...
Kalonia Harikesh - - 2010
Role of cyclooxygenase (COX) enzyme has been well documented in both physiological and pathological conditions. COX-1 and COX-2 converts arachidonic acid into prostaglandins. Non-selective inhibition of COXs produces undesirable effects, whereas selective COX-2 inhibition produces protective effects in various inflammatory diseases. Recently, cyclooxygenase (COX) inhibitors have been implicated as a ...
Picazo Ofir - - 2010
17alpha-ethynylestradiol (EE2), a major constituent of many oral contraceptives, is similar in structure to 17beta-estradiol, which has neuroprotective properties in several animal models. This study explored the potential neuroprotective actions of EE2 against kainic and quinolinic acid toxicity in the hippocampus of adult ovariectomized Wistar rats. A decrease in the ...
Gill Santokh - - 2010
Domoic acid produced by marine algae has been shown to cause acute and chronic neurologic sequelae in Californian sea lions following acute or low-dose exposure. Histological findings in affected animals included a degenerative cardiomyopathy that was hypothesized to be caused by over-excitation of the glutamate receptors (GluRs) speculated to be ...
El-Naggar Tarek - - 2010
Nigella sativa L. (NS) has been used for medicinal purposes since ancient times. This study aimed to investigate the cytotoxicity of NS dry methanolic extract on cultured cortical neurons and its influence on neurotransmitter release, as well as the presence of excitatory (glutamate and aspartate) and inhibitory amino acids (gamma-aminobutyric ...
Kim Yun B - - 2010
Midkine (MK), a member of the heparin-binding growth factor family, which includes MK and pleiotrophin, is known to possess neurotrophic and neuroprotective properties in the central nervous system. Previous studies have shown that MK is an effective neuroprotective agent in reducing retinal degeneration caused by excessive light and decreasing hippocampal ...
Lim Eui Sung - - 2010
The intrathecal (IT) administration of glycine or GABA(A) receptor antagonist result in a touch evoked allodynia through disinhibition in the spinal cord. Glycine is an inhibitory neurotransmitter that appears to be important in sensory processing in the spinal cord. This study was aimed to evaluate the effect of glycine-related amino ...
Chai Changhoon - - 2010
This study describes the direct detection of the biological toxin (Ricin) in acidic environment without pH adjustment by hydrophobically modified electrochemical impedance immunosensor (EII). The nano-porous aluminum substrate for EII was hydrophobically modified via self-assembled monolayer (SAM) of APTES. Biosensor for the detection of the Ricin was fabricated by the ...
Marosi M?t? - - 2010
Kynurenic acid is an endogenous product of the tryptophan metabolism, and as a broad-spectrum antagonist of excitatory amino acid receptors may serve as a protective agent in neurological disorders. The use of kynurenic acid as a neuroprotective agent is rather limited, however, because it has only restricted ability to cross ...
Nagamizu Masaya - - 2009
SEA SNAKES (FAMILY: Hydrophiidae) are serpents found in the coastal areas of the Indian and Pacific Oceans. There are two subfamilies in Hydrophiidae: Hydrophiinae and Laticaudinae. A toxin, aagardi toxin, was isolated from the venom of the Hydrophiinae snake, Hydrophis torquatus aagardi and its chemical properties such as molecular weight, ...
Kalonia Harikesh - - 2009
OBJECTIVE: The neuroprotective roles of cyclooxygenase (COX) and lipooxygenase (LOX) inhibitors have been well documented. Quinolinic acid (QA) is a well-known excitotoxic agent that could induce behavioral, morphological and biochemical alterations similar with symptoms of Huntington's disease (HD), by stimulating NMDA receptors. However, the exact roles of COX and LOX ...
Komori Yumiko - - 2009
Both sea snakes and cobras have venoms containing postsynaptic neurotoxins. Comparison of the primary structures indicates many similarities, especially the positions of the four disulfide bonds. However, detailed examination reveals differences in several amino acid residues. Amino acid sequences of sea snake neurotoxins were determined, and then compared to cobra ...
Ogaya Tadahiro - - 2010
Using a microdialysis technique, we continuously infused D-kynurenine (KYN) (0, 50, and 100 microM) into the prefrontal cortices (PFCs) of male Sprague-Dawley rats. We then used column-switching high-performance liquid chromatography to assess the alterations in the concentration of kynurenic acid (KYNA)-an antagonist of N-methyl-D-aspartate and alpha7 nicotinic acetylcholine receptors-in the ...
Ruiz Nicolas - - 2010
Peptaibols are small linear fungal peptides which are produced in the marine environment. They exhibit neurotoxicity by forming pores in neuronal membranes. This work describes their combine effect with domoic acid, a neurotoxic phycotoxin, on Diptera larvae. The Acute toxicity bioassay on this biological model was tested with a panel ...
Kalonia Harikesh - - 2009
Huntington's Disease (HD) is a common neurodegenerative disorder characterized by motor disturbances, subcortical dementia and psychiatric disturbances. Pathogenesis of HD revolves so far around excitatory amino acids as the primary cause of neuronal loss. However, number of recent reports suggests the involvement of excitotoxicity and oxidative damage. In the present ...
Kolmakov Nikolay N - - 2009
Exposure of olfactory epithelium to environmentally relevant concentrations of copper disrupts olfaction in fish. To examine the dynamics of recovery at both functional and morphological levels after acute copper exposure, unilateral exposure of goldfish olfactory epithelia to 100 microM CuSO(4) (10 min) was followed by electro-olfactogram (EOG) recording and scanning ...
Patwardhan Amol M - - 2009
Transient receptor potential vanilloid 1 (TRPV1) plays a major role in hyperalgesia and allodynia and is expressed both in the peripheral and central nervous systems (CNS). However, few studies have evaluated mechanisms by which CNS TRPV1 mediates hyperalgesia and allodynia after injury. We hypothesized that activation of spinal cord systems ...
Blanco Juan - - 2010
The presence of ASP toxins in Luanda Bay, an area 2700 km apart from the closest record of this type of toxicity and with a different hydrographic regime, was studied. Two outbreaks were confirmed by LC/MS/MS with presence of domoic acid and some isomers both, in plankton and in three ...
Zemlyak Ilona - - 2009
NAP (NAPVSIPQ, generic name, davunetide), a neuroprotective peptide in clinical development for neuroprotection against Alzheimer's disease and other neurodegenerative indications, has been recently shown to provide protection against kainic acid excitotoxicity in hippocampal neuronal cultures. In vivo, kainic acid toxicity models status epilepticus that is associated with hippocampal cell death. ...
Miltiadous Panagiota - - 2010
Insulin-like growth factor I (IGF-I) has been shown to act as a neuroprotectant both in in vitro studies and in in vivo animal models of ischemia, hypoxia, trauma in the brain or the spinal cord, multiple and amyotrophic lateral sclerosis, Alzheimer's and Parkinson's disease. In the present study, we investigated ...
Lewerenz Jan - - 2009
In amyotrophic lateral sclerosis, down-regulation of the astrocyte-specific glutamate excitatory amino acid transporter 2 is hypothesized to increase extracellular glutamate, thereby leading to excitotoxic motor neuron death. The antibiotic ceftriaxone was recently reported to induce excitatory amino acid transporter 2 and to prolong the survival of mutant superoxide dismutase 1 ...
Lefebvre Kathi A - - 2010
Domoic acid is a potent neurotoxin that is naturally produced by several diatom species of the genus Pseudo-nitzschia. The toxin acts as a glutamate agonist and is excitotoxic in the vertebrate central nervous system and other glutamate receptor-rich organs. Human exposure to domoic acid occurs via the consumption of contaminated ...
Bunch Lennart - - 2009
BACKGROUND: Excitatory amino acid transporters (EAATs) are transmembrane proteins responsible for the uptake of (S)-glutamate (Glu) from the synaptic cleft, thereby terminating the glutamatergic neurotransmitter signal. Today five subtypes have been identified. Except for EAAT2, their individual roles or functions in the CNS are yet to be fully understood due ...
Tzvetanova Elina - - 2009
In-vivo effects of nociceptin (N/OFQ(1-13)NH(2)) on the levels of lipid peroxidation and cell enzyme (superoxide dismutase, glutathione peroxidase and glutathione reductase) and non-enzyme (glutathione) antioxidants in brain of control and kainic acid-treated rats were studied. N/OFQ(1-13)NH(2) effects were compared with those of its structural analogue [Orn(9)]N/OFQ(1-13)NH(2). Kainic acid (25 microg, ...
Kumar K Prem - - 2009
Risk assessment of the amnesic shellfish poison, domoic acid, a potent neurotoxin, is evaluated based on its current knowledge and its harmful effects, and is presented under four headings, viz., (1) hazard identification, (2) dose response assessment, (3) exposure assessment and (4) risk characterization. Domoic acid binds the glutamate receptor ...
Radhakrishnan Rajan - - 2009
Two injections of acidic saline into the gastrocnemius muscle produce long-lasting hyperalgesia that is initiated and maintained by changes in the rostroventromedial medulla (RVM). Potential underlying mechanisms could be increased release of excitatory neurotransmitters and/or reduced release of inhibitory neurotransmitters, in the RVM. We tested this hypothesis by measuring concentrations ...
Vamos Eniko - - 2009
The metabolism of tryptophan mostly proceeds through the kynurenine pathway. The biochemical reaction includes both an agonist (quinolinic acid) at the N-methyl-d-aspartate receptor and an antagonist (kynurenic acid). Besides the N-methyl-d-aspartate antagonism, an important feature of kynurenic acid is the blockade of the alpha7-nicotinic acetylcholine receptor and its influence on ...
Smith Andrew J - - 2009
The essential amino acid tryptophan is primarily metabolised through the kynurenine pathway, some components of which may be neurotoxic. We have now examined the potential toxicity of several kynurenine metabolites in relation to the generation of oxidative stress and activation of cell death signalling pathways in cultured cerebellar granule neurons. ...
Champeil Elise - - 2009
The optimum geometries and binding energies of the complexes formed by AMPA and Kainic acid, as well as their anions with tyrosine, proline and some tripeptides are investigated with quantum chemical calculations (HF/6-31G**). It was found that receptors featuring the Tyr-Ala-Pro sequence exhibit stronger binding energies to the substrates than ...
Jiang Wei - - 2009
Ketamine, a non-competitive N-methyl-D-aspartate (NMDA) antagonist, is a commonly used injectable anaesthetic agent. In the present study, ketamine- and isoflurane-induced anaesthesias were tested to identify the influence of different anaesthesia methods in conjunction with the unilateral quinolinic acid-induced excitotoxic lesion rat model of Huntington's disease (HD). Quinolinic acid, a glutamate ...
Swamy Mummedy - - 2009
Neuronal excitation, involving the excitatory glutamate receptors, is recognized as an important underlying mechanism in neurodegenerative disorders. To understand their role in excitotoxicity, the nitric oxide synthase (NOS), argininosuccinate synthetase (AS), argininosuccinate lyase (AL), glutamine synthetase (GS), and arginase activities, along with the concentration of nitrate/nitrite, thiobarbituric acid-reactive substances (TBARS), ...
Ji Chao - - 2009
Excitotoxicity is one of the most extensively studied processes of neuronal death and plays an important role in Alzheimer's disease. In the present study, the protective effects of Gossypium herbaceam extracts (GHE) on learning and memory impairment induced by excitatory neurotoxin ibotenic acid were examined in vivo using Morris water ...
Filosa Rosanna - - 2009
A novel series of bicyclo[1.1.1]pentane-based omega-acidic amino acids, including (2S)- and (2R)-3-(3'-carboxybicyclo[1.1.1]pentyl)alanines (8 and 9), (2S)- and (2R)-2-(3'-carboxymethylbicyclo[1.1.1]pentyl)glycines (10 and 11), and (2S)- and (2R)-3-(3'-phosphonomethylbicyclo[1.1.1]pentyl)glycines (12 and 13), were synthesized and evaluated as glutamate receptor ligands. Among them, (2R)-3-(3'-phosphonomethylbicyclo[1.1.1]pentyl)glycine (13) showed relatively high affinity and selectivity at the NMDA receptor. ...
Munday Rex - - 2008
Seafood in many parts of the world may become contaminated with high levels of domoic acid and domoic acid isomers, and such seafood has been shown to cause toxic effects in humans and in marine animals. Domoic acid itself has been held responsible for the observed effects, although the possible ...
Wang Ying Y Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, FL, - - 2008
Mammalian neuronal DEG/ENaC channels known as ASICs (acid-sensing ion channels) mediate sensory perception and memory formation. ASICS are closed at rest and are gated by protons. Members of the DEG/ENaC family expressed in epithelial tissues are called ENaCs and mediate Na(+) transport across epithelia. ENaCs exhibit constitutive activity and strict ...
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