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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2004-3-4
pubmed:abstractText
Human hereditary hyperekplexia ("startle disease") is a neurological disorder characterized by exaggerated, convulsive movements in response to unexpected stimuli. Molecular genetic studies have shown that this disease is often caused by amino acid substitutions at arginine 271 to glutamine or leucine of the alpha1 subunit of the inhibitory glycine receptor (GlyR). When exogenously expressed in Xenopus oocytes, agonist responses of mutant alpha1(R271Q) and alpha1(R271L) GlyRs show higher EC50 values and lower maximal inducible responses (relative efficacies) compared with oocytes expressing wild-type alpha1 GlyR subunits. Here, we report that the maximal glycine-induced currents (I(max)) of mutant alpha1(R271Q) and alpha1(R271L) GlyRs were dramatically potentiated in the presence of the anesthetic propofol (PRO), whereas the I(max) of wild-type alpha(1) receptors was not affected. Quantitative analysis of the agonist responses of the isofunctionally substituted alpha1(R271K) mutant GlyR revealed that saturating concentrations of PRO decreased the EC50 values of both glycine and the partial agonist beta-alanine by >10-fold, with relative efficacies increasing by 4- and 16-fold, respectively. Transgenic (tg) mice carrying the alpha1(R271Q) mutation (tg271Q-300) have both spontaneous and induced tremor episodes that closely resemble the movements of startled hyperekplexic patients. After treatment with subanesthetic doses of PRO, the tg271Q-300 mutant mice showed temporary reflexive and locomotor improvements that made them indistinguishable from wild-type mice. Together, these results demonstrate that the functional and behavioral effects of hyperekplexia mutations can be effectively reversed by drugs that potentiate GlyR responses.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1529-2401
pubmed:author
pubmed:issnType
Electronic
pubmed:day
3
pubmed:volume
24
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2322-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:14999083-Anesthetics, Intravenous, pubmed-meshheading:14999083-Animals, pubmed-meshheading:14999083-Ataxia, pubmed-meshheading:14999083-Behavior, Animal, pubmed-meshheading:14999083-Cells, Cultured, pubmed-meshheading:14999083-Dose-Response Relationship, Drug, pubmed-meshheading:14999083-Gene Transfer Techniques, pubmed-meshheading:14999083-Glycine, pubmed-meshheading:14999083-Glycine Agents, pubmed-meshheading:14999083-Humans, pubmed-meshheading:14999083-Mice, pubmed-meshheading:14999083-Mice, Transgenic, pubmed-meshheading:14999083-Motor Activity, pubmed-meshheading:14999083-Oocytes, pubmed-meshheading:14999083-Patch-Clamp Techniques, pubmed-meshheading:14999083-Propofol, pubmed-meshheading:14999083-Reaction Time, pubmed-meshheading:14999083-Receptors, Glycine, pubmed-meshheading:14999083-Recombinant Proteins, pubmed-meshheading:14999083-Startle Reaction, pubmed-meshheading:14999083-Tremor, pubmed-meshheading:14999083-Xenopus
pubmed:year
2004
pubmed:articleTitle
Propofol restores the function of "hyperekplexic" mutant glycine receptors in Xenopus oocytes and mice.
pubmed:affiliation
Abteilung Neurochemie, Max-Planck-Institut für Hirnforschung, 60528 Frankfurt am Main, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't