Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We describe here a new strategy for the treatment of stroke, through the inhibition of NAALADase (N-acetylated-alpha-linked-acidic dipeptidase), an enzyme responsible for the hydrolysis of the neuropeptide NAAG (N-acetyl-aspartyl-glutamate) to N-acetyl-aspartate and glutamate. We demonstrate that the newly described NAALADase inhibitor 2-PMPA (2-(phosphonomethyl)pentanedioic acid) robustly protects against ischemic injury in a neuronal culture model of stroke and in rats after transient middle cerebral artery occlusion. Consistent with inhibition of NAALADase, we show that 2-PMPA increases NAAG and attenuates the ischemia-induced rise in glutamate. Both effects could contribute to neuroprotection. These data indicate that NAALADase inhibition may have use in neurological disorders in which excessive excitatory amino acid transmission is pathogenic.
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PMID:Selective inhibition of NAALADase, which converts NAAG to glutamate, reduces ischemic brain injury. 1058 Oct 82

GCP II inhibition decreases extracellular excitotoxic glutamate and increases extracellular NAAG, both of which provide neuroprotection. We have demonstrated with our potent and selective GCP II inhibitors efficacy in models of stroke, ALS and neuropathic pain. GCP II inhibition may have significant potential benefits over existing glutamate-based neuroprotection strategies. The upstream mechanism seems selective for excitotoxic induced glutamate release, as GCP II inhibitors in normal animals induced no change in basal glutamate. This suggestion has recently been corroborated by Lieberman and coworkers24 who found that both NAAG release and increase in GCP II activity appear to be induced by electrical stimulation in crayfish nerve fibers and that subsequent NAAG hydrolysis to glutamate contributes, at least in part, to subsequent NMDA receptor activation. Interestingly, even at relatively high doses of compounds, GCP II inhibition did not appear to be associated with learning/memory deficits in animals. Additionally, quantitative neurophysiological testing data and visual analog scales for 'psychedelic effects' in Phase I single dose and repeat dose studies showed GCP II inhibition to be safe and well tolerated by both healthy volunteers and diabetic patients. GCP II inhibition may represent a novel glutamate regulating strategy devoid of the side effects that have hampered the development of postsynaptic glutamate receptor antagonists.
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PMID:Glutamate carboxypeptidase II (NAALADase) inhibition as a novel therapeutic strategy. 1680 24

N-acetylated-alpha-linked-acidic peptidase (NAAG peptidase) converts N-acetyl-aspartyl-glutamate (NAAG, mGluR3 agonist) into N-acetyl-aspartate and glutamate. The NAAG peptidase inhibitor 2-PMPA (2-(phosphonomethyl)pentanedioic acid) had neuroprotective activity in an animal model of stroke and anti-allodynic activity in CCI model despite its uncertain ability to penetrate the blood-brain barrier. The NAAG concentration in brain ECF under basal conditions and its alteration in relation to the brain ECF concentration of 2-PMPA is unclear. We therefore assessed those brain concentrations after i.p. administration of 2-PMPA, using in vivo microdialysis combined with LC/MS/MS analysis. Administration of 2-PMPA (50mg/kg) produced a mean peak concentration of 2-PMPA of 29.66+/-8.1microM. This concentration is about 100,000 fold more than is needed for inhibition of NAAG peptidase, and indicates very good penetration to the brain. Application of 2-PMPA was followed by a linear increase of NAAG-concentration reaching a maximum of 2.89+/-0.42microM at the end of microdialysis. However, during the time the anti-allodynic effects of 2-PMPA were observed, the NAAG concentration in the ECF did not reach levels which are likely to have an impact on any known target. It appears therefore that the observed behavioural effects of 2-PMPA may not be mediated by NAAG nor, in turn, by mGluR3 receptors.
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PMID:Effects of NAAG peptidase inhibitor 2-PMPA in model chronic pain - relation to brain concentration. 1692 34