Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020672 (hypothermia)
 17,327 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Binding of the peripheral benzodiazepine receptor ligand, [3H]-PK 11195, to rat hippocampal membranes has been used to quantify the reactive gliosis resulting from neuronal death induced by intraperitoneally administered kainic acid. 2. Intraperitoneal administration of kainic acid (10 mg kg-1) caused a 350-500% increase in [3H]-PK 11195 binding measured in rat hippocampal P2 membranes 7 days later. Co-treatment with the adenosine derivative R-phenylisopropyladenosine (R-PIA) (100, 25 or 10 micrograms kg-1, i.p.) abolished this elevation. The protective action of R-PIA could itself be abolished by co-treatment with 8-phenyltheophylline (1 mg kg-1). 3. Body temperatures were recorded in the antagonist experiments and no significant changes were recorded, suggesting that the protective action of R-PIA was not mediated by hypothermia. 4. Since systemic kainic acid-induced neurotoxicity has been claimed as a good model of neuronal death in temporal lobe epilepsy, the results suggest that the systemic administration of purines in low doses may provide protection against certain neurodegenerative insults.
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PMID:Inhibition by the adenosine analogue, (R-)-N6-phenylisopropyladenosine, of kainic acid neurotoxicity in rat hippocampus after systemic administration. 835 36

The aim of the present investigation was to analyze the molecular mechanism(s) of diazepam neuroprotection in two models of selective neuronal death in CA1 sector of hippocampus: in vivo following transient gerbil brain ischemia and in vitro in rat hippocampal brain slices subjected to glutamatergic (100 microM NMDA) or oxidative (30 microM tertbutyl-hydroksyperoxide (TBH)) stress. In the in vivo model the diazepam treatment (two doses of 10mg/kg i.p. 30 and 90 min after the insult) resulted in more than 60% of CA1 hippocampal neurons surviving the insult comparing with 15% in untreated animals. To test whether the protective effect of diazepam was due to the postulated drug-induced hypothermia we followed the fluxes of body temperature during postischemic reperfusion: diazepam reduced temperature from 36.6+/-1 degrees C to 33.4+/-2 degrees C. Equivalent hypothermia induced and maintained in animals after ischemia did not prevent neuronal cell loss to the same extent as diazepam did (42.8+/-9.2% and 72.4+/-14.5% of live neurons, respectively). In vitro, under constant temperature conditions, diazepam exerted neuroprotective effects following a "U-shaped" dose-response curve, with concentration efficacy window of 0.5-10 microM. Five micro-molar diazepam showed significant protection by reducing over 50% the number of (dead) propidium iodide labeled cells even in the presence of GABA(A) receptor antagonist bicuculline. Next, we have shown that diazepam reduced the efflux of cytochrome c out of mitochondria both in compromised CA1 neurons in vitro and in isolated mitochondria treated with 30 microM THB. Our results suggest that the neuroprotective action of diazepam relies on additional mechanism(s) and not solely on its hypothermic effect. We suggest that diazepam evokes neuroprotection through its central receptors located on the GABA(A) receptor complex and, possibly, through its peripheral receptor, the translocator protein TSPO (previously called the peripheral benzodiazepine receptor) located in the outer mitochondrial membrane.
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PMID:Diazepam neuroprotection in excitotoxic and oxidative stress involves a mitochondrial mechanism additional to the GABAAR and hypothermic effects. 1942 22