Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036572 (seizures)
 80,221 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It has been repeatedly reported that NMDA receptors may contribute to ethanol-induced discriminative stimulus effects and withdrawal syndrome. However, the role of NMDA receptors in the reinforcing properties of ethanol remains unclear. The aim of the present study was to evaluate effects of the novel low-affinity, uncompetitive NMDA receptor antagonist, 1-amino-1,3,3,5,5-pentamethyl-cyclohexane hydrochloride (MRZ 2/579), on ethanol self-administration and ethanol withdrawal-associated seizures in rats. Both an operant (lever pressing for ethanol) and non-operant two-bottle choice setups were employed to initiate ethanol self-administration. In another procedure, forced treatment with high doses (9--15 g/kg/day) was used to induce physical dependence on ethanol. MRZ 2/579 delivered chronically by osmotic minipumps (9.6 mg/day, s.c.) did not alter either operant or non-operant ethanol drinking behaviour in a maintenance phase of ethanol self-administration. In contrast, repeated daily injections of the drug (5 mg/kg, i.p.) led to a progressive decrease in operant responding for ethanol. MRZ 2/579 (0.5--7.5 mg/kg, i.p.) and another low-affinity NMDA receptor antagonist, memantine (1--10 mg/kg, i.p.) dose-dependently suppressed ethanol withdrawal seizures with efficacies comparable with that of a standard benzodiazepine derivative, diazepam. The results of the present study indicate that: (i) intermittent administration of MRZ 2/579 may lead to a gradual decrease of operant responding for ethanol; and (ii) the group of low-affinity uncompetitive NMDA receptor antagonists may be an interesting alternative to benzodiazepines in the treatment of alcohol withdrawal.
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PMID:Effects of a novel uncompetitive NMDA receptor antagonist, MRZ 2/579 on ethanol self-administration and ethanol withdrawal seizures in the rat. 1117 66

The effect of chronic administration of the novel anxiolytic beta-carboline derivative, abecarnil (isopropyl-6-benzyloxy-4-methoxymethyl-beta-carboline-3-carboxylate), was examined and compared with the capability of diazepam to induce physical dependence in cats. The acute administration of the benzodiazepine receptor antagonist, flumazenil (20mg/kg i.p.), to cats treated for 2 weeks with diazepam (7mg/kg i.p., three times daily), induced a severe withdrawal syndrome characterized by the appearance of severe physical signs. Within minutes all cats displayed tremors, increased muscle tone, fear response, repeated vocalization and salivation. On the contrary, in all cats treated chronically (2 weeks) with abecarnil (7mg/kg i.p. three times daily) the challenge dose of flumazenil failed to precipitate a clear abstinence syndrome. In fact, a pupillary dilatation and a mild fear response were the only signs present 15-30min after flumazenil administration. This finding indicates that abecarnil, a new potential therapeutic agent for anxiety disorders and seizures, might have advantages over classical benzodiazepines with regard to development of physical dependence.
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PMID:Failure of flumazenil to precipitate a withdrawal syndrome in cats chronically treated with the new anxioselective beta-carboline derivative abecarnil. 1122 21

Neuroendocrine specific protein or reticulon 1 (NSP/RTN1) was identified as a putative ethanol-regulated gene using mRNA differential display in mice genetically selected for severe ethanol withdrawal (withdrawal seizure-prone, WSP). One transcript of RTN1 (3.0 kb) showed a statistically significant increase (13%) in relative abundance in whole brain of ethanol-treated WSP mice but not in mice selected for resistance to ethanol withdrawal convulsions (WSR). We hypothesized that ethanol-induced regulation of gene expression of mRTN1 is specific to mice predisposed to exhibit severe ethanol withdrawal and that the gene might be regulated differentially in specific brain regions. WSP and WSR selected lines and DBA/2J and C57BL/6J inbred strains of mice were exposed to ethanol vapor or air for 72 h. mRNA steady-state expression of RTN1 was assessed in hippocampus, cortex, and cerebellum. Results indicated that the pattern of ethanol-induced changes in gene expression was dependent upon transcript size, brain region, and genotype. Modest increases in the relative abundance of both transcripts of RTN1 were observed in the hippocampus and cortex of all ethanol-treated mice. Results from cerebellum showed a moderate decrease in expression of RTN1 (3.0 kb transcript) in WSP and DBA/2J mice, but not in the mice resistant to ethanol withdrawal (C57BL/6J and WSR). These results suggest a genotype-specific effect of chronic ethanol exposure on steady-state mRNA levels of RTN1 in the cerebellum. Overall, the results indicate a complex pattern of ethanol-induced regulation of the putative mouse homologue of RTN1 and suggest that specific brain regional changes may be involved in the expression of physical dependence.
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PMID:Ethanol-regulated gene expression of neuroendocrine specific protein in mice: brain region and genotype specificity. 1128 67

The mechanisms by which nitrous oxide (N(2)O) produces physical dependence and withdrawal seizures are not well understood, but both N(2)O and ethanol exert some of their effects via the GABA(A) receptor and several lines of evidence indicate that withdrawal from N(2)O and ethanol may be produced through similar mechanisms. Expression levels of mRNA transcripts encoding several GABA(A) receptor subunits change with chronic ethanol exposure and, therefore, we hypothesized that N(2)O exposure would produce changes in mRNA expression for the alpha(1) subunit. Male, Swiss--Webster mice, 10--12 weeks of age, were exposed for 48 h to either room air or a 75%:25% N(2)O:O(2) environment. Brains were sectioned and mRNA for the alpha(1) subunit was detected by in situ hybridization using an 35S-labelled cRNA probe. N(2)O exposure produced a significant increase in expression levels of the alpha(1) subunit mRNA in the cingulate cortex, the CA1/2 region of the hippocampus, the dentate gyrus, the subiculum, the medial septum, and the ventral tegmental area. These results lend support to the hypothesis that N(2)O effects are produced, at least in part, through the GABA(A) receptor and that N(2)O produces these effects through actions in the cingulate cortex, hippocampus, ventral tegmental area and medial septum. These results are also further evidence that ethanol and N(2)O produce dependence and withdrawal through common mechanisms.
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PMID:Increased mRNA expression for the alpha(1) subunit of the GABA(A) receptor following nitrous oxide exposure in mice. 1131 74

Risk for onset of alcoholism is related to genetic differences in acute alcohol withdrawal liability. We previously mapped a locus responsible for 26% of the genetic variance in acute alcohol withdrawal convulsion liability to a >35 centimorgan (cM) interval of murine chromosome 4. Here, we narrow the position of this locus to a <1 cM interval (approximately 1.8 megabase, containing 15 genes and/or predicted genes) using a combination of novel, interval-specific congenic strains and recombinant progeny testing. We report the development of a small-donor-segment congenic strain, which confirms capture of a gene affecting alcohol withdrawal within the <1 cM interval. We also confirm a pentobarbital withdrawal locus within this interval, suggesting that the same gene may influence predisposition to physiological dependence on alcohol and a barbiturate. This congenic strain will be invaluable for determining whether this interval also harbors a gene(s) underlying other quantitative trait loci mapped to chromosome 4, including loci affecting voluntary alcohol consumption, alcohol-induced ataxia, physical dependence after chronic alcohol exposure, and seizure response to pentylenetetrazol or an audiogenic stimulus. To date, Mpdz, which encodes the multiple PSD95/DLG/ZO-1 (PDZ) domain protein (MPDZ), is the only gene within the interval shown to have allelic variants that differ in coding sequence and/or expression. Sequence analysis of 15 standard inbred mouse strains identifies six Mpdz haplotypes that predict three MPDZ protein variants. These analyses, and evidence using interval-specific congenic lines, show that alcohol withdrawal severity is genetically correlated with MPDZ status, indicating that MPDZ variants may influence alcohol withdrawal liability.
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PMID:Congenic mapping of alcohol and pentobarbital withdrawal liability loci to a <1 centimorgan interval of murine chromosome 4: identification of Mpdz as a candidate gene. 1197 49

Ethanol (alcohol) withdrawal-induced convulsions are a key index of physical dependence on ethanol and a clinically important consequence of alcohol abuse in humans. In rodent models, severity of withdrawal is strongly influenced by genotype. For example, many studies have reported marked differences in withdrawal severity between the WSR (Withdrawal Seizure Resistant) and WSP (Withdrawal Seizure Prone) mouse strains selectively bred for over 25 generations to differ in chronic withdrawal severity. Therefore, we used an F(2) intercross between the inbred WSP and WSR strains for a genome-wide search for quantitative trait loci (QTLs), which are chromosomal sites containing genes influencing the magnitude of withdrawal. We also used the recently developed HW, RHW (high withdrawal) and LW, RLW (low withdrawal) lines selectively bred for the same trait and in the same manner as the WSP, WSR lines. QTL analysis was then used to dissect the continuous trait distribution of withdrawal severity into component loci, and to map them to broad chromosomal regions by using the Pseudomarker 0.9 and Map Manager QT29b programs. This genome-wide search identified five significant QTLs influencing chronic withdrawal severity on Chromosomes (Chrs) 1 (proximal), 4 (mid), 8 (mid), 11 (proximal), and 14 (mid), plus significant interactions (epistasis) between loci on Chr 11 with 13, 4 with 8, and 8 with 14.
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PMID:Chromosomal loci influencing chronic alcohol withdrawal severity. 1292 94

(1) Amphetamine-like drugs are not only authorised for use as appetite suppressants. (2) Bupropion, otherwise known as amfebutamone, is licensed as an aid to smoking withdrawal. It has amphetamine-like adverse effects, such as seizures; in addition it causes hypersensitivity reactions. (3) Benfluorex is sold in France as an adjunctive treatment for hypertriglyceridemia and diabetes with overweight. The lack of data on its adverse effects is hardly reassuring. A case of severe cardiac valve disease has been published. (4) The ephedrine derivatives norephedrine (phenylpropanolamine) and pseudoephedrine are used in ENT as decongestants because of their vasoconstrictive properties. They expose patients to serious cardiovascular risks. Ephedrine and plants belonging to the genus Ephedra (used in freshly prepared appetite suppressant mixtures) have negative risk-benefit ratios. (5) Methylphenidate is used as a psychostimulant in patients with narcolepsy and children with attention-deficit disorder. It can lead to serious mental and physical dependence.
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PMID:Hidden amphetamines: from smoking cessation to diabetes. 1505 18

Zolpidem is a sedative and hypnotic drug belonging to imidazopyridine family. Zolpidem facilitates GABAA function more selectively than benzodiazepines, and produces a selective hypnotic effect. In comparison with benzodiazepines this mechanism could be reduce liability to induce dependence. Recently, some cases of zolpidem abuse and dependence have been published. The Authors report 2 cases of addiction to high dose of zolpidem and compare them with others described in the literature. Both patients had been reknown drug addicts before their first prescription of zolpidem and a borderline personality disorder was diagnosed. The patients rapidly developed over consumption and dependence of the molecule, when taking doses as high as 240 and 400 mg daily. To get zolpidem, one patient falsifies prescriptions. They don't suffer from the sedative effects while searching for anxiolytic and stimulating effects. They were also dysarthric, confused, high energy for mental and physical activity. The cases of zolpidem abuse and dependence in the literature describe these symptoms and others such as losing sense of orientation in time and space, amnesia and visual hallucinations. The most typical withdrawal symptom is high levels of anxiety. Moreover, one patient presents an epileptic seizure whereas the other display a severe psychiatric complication such a psychosis. In the literature, withdrawal was accompanied by confusion, suicidal ideas, nausea, vomiting, sweat, tremors, tachycardia and insomnia rebound. The epileptic seizures are described but acute psychosis complication is rare. Pharmacological hypotheses are described. The effects of zolpidem on GABAA receptor gene expression are consistent with the reduced tolerance liability of this drug as well as with other ability to induce both physical dependence and withdrawal syndrome. Through the review of the literature, the Authors noted that 50% of the cases of dependence on zolpidem are drug addicts, therefore concluding that drug addicts are more likely to become dependent on zolpidem.
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PMID:[Dependence on zolpidem: a report of two cases]. 1510 18

Most evidence agrees that levels of methionine enkephalin (Met-Enk) in brain are inversely correlated with ethanol drinking and withdrawal seizures. One area of discrepancy is the effect of chronic ethanol administration on the level of immunoactive Met-Enk in brain, with some authors reporting increased and others reporting decreased levels. These reports differed greatly in terms of method of ethanol administration, species used, length of time ethanol was administered, and the region of brain examined. We found that all studies could be resolved by considering only length of time ethanol was administered, with Met-Enk levels first increasing and then decreasing. We tested this finding by determining the effect of 4-56 days of ethanol delivered in liquid feed on levels of brain Met-Enk. We found that brain levels of Met-Enk peaked after 7 days of ethanol ingestion and declined to levels lower than control by 28 days. Exposure to ethanol abolished a correlation between brain and serum levels of Met-Enk which occurred in controls. HPLC showed that whereas 100% of immunoactivity eluted in the position of Met-Enk in controls, only about 50% eluted as Met-Enk in mice exposed to ethanol. These results support the hypothesis that exposure to ethanol alters brain Met-Enk in a way consistent with the reinforcement of physical dependence.
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PMID:Effects of chronic ethanol on brain and serum level of methionine enkephalin. 1512 45

Chronic ethanol abuse causes up-regulation of NMDA receptors, which underlies seizures and brain damage upon ethanol withdrawal (EW). Here we show that tissue-plasminogen activator (tPA), a protease implicated in neuronal plasticity and seizures, is induced in the limbic system by chronic ethanol consumption, temporally coinciding with up-regulation of NMDA receptors. tPA interacts with NR2B-containing NMDA receptors and is required for up-regulation of the NR2B subunit in response to ethanol. As a consequence, tPA-deficient mice have reduced NR2B, extracellular signal-regulated kinase 1/2 phosphorylation, and seizures after EW. tPA-mediated facilitation of EW seizures is abolished by NR2B-specific NMDA antagonist ifenprodil. These results indicate that tPA mediates the development of physical dependence on ethanol by regulating NR2B-containing NMDA receptors.
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PMID:Ethanol-withdrawal seizures are controlled by tissue plasminogen activator via modulation of NR2B-containing NMDA receptors. 1615 19


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