Search results for "Glutamic acid"
showing 8 items of 168 documents
Glutamatergic activation of hippocampal phospholipase D: postnatal fading and receptor desensitization.
2002
Abstract: Phospholipase D (PLD) activity was determined in rat hippocampal slices between postnatal days 3 and 35. After birth, basal PLD activity was low and, within 2 weeks, increased to reach a plateau that was maintained up to the adult age. Likewise the response to glutamate developed postnatally to reach a maximum at day 8, but then faded rapidly and was almost absent at day 35. Activation of PLD by 4β-phorbol 12β,13α-dibutyrate (PDB) was independent of age, whereas the effect of aluminum fluoride (AlF4−) increased to a plateau within the first week. At day 8, PLD stimulation by glutamate via metabotropic receptors involved protein kinase C activation, but was independent of Ca2+ infl…
Transient focal cerebral ischemia significantly alters not only EAATs but also VGLUTs expression in rats: relevance of changes in reactive astroglia
2010
The involvement of plasma membrane glutamate transporters (EAATs - excitatory aminoacid transporters) in the pathophysiology of ischemia has been widely studied, but little is known about the role of vesicular glutamate transporters (VGLUTs) in the ischemic process. We analyzed the expression of VGLUT1-3 in the cortex and caudate-putamen of rats subjected to transient middle cerebral artery occlusion. Western blot and immunohistochemistry revealed an increase of VGLUT1 signal in cortex and caudate-putamen until 3 days of reperfusion followed by a reduction 7 days after the ischemic insult. By contrast, VGLUT2 and 3 were drastically reduced. Confocal microscopy revealed an increase in VGLUT2…
Inhibition of intracellular Ca2+ release by a Rho-kinase inhibitor for the treatment of ischemic damage in primary cultured rat hippocampal neurons.
2008
The effects of hydroxy fasudil, a specific Rho-kinase inhibitor, on behavior and brain neuronal activity in animal studies have been described previously. However, whether a Rho-kinase inhibitor can directly protect neurons against ischemic damage and the molecular mechanisms underlying these effects are poorly understood. The present work was designed to investigate the effect of hydroxy fasudil against oxygen-glucose deprivation (OGD) induced acute neuronal injury and the underlying mechanisms in vitro. Pretreatment with hydroxy fasudil at 5 and 10 microM could concentration-dependently improve cell viability and decrease Lactate dehydrogenase (LDH) level in extracellular solution of neur…
Intestinal ischaemia during cardiac arrest and resuscitation: comparative analysis of extracellular metabolites by microdialysis.
2003
Intestinal ischaemia is a major complication of shock syndromes causing translocation of bacteria and endotoxins and multiple organ failure in intensive care patients. The present study was designed to use microdialysis as a tool to monitor intestinal ischaemia after cardiac arrest and resuscitation in pigs. For this purpose, microdialysis probes were implanted in pig jejunal wall, peritoneum, skeletal muscle and brain, and interstitial fluid was obtained during circulatory arrest (induced by ventricular fibrillation) and after return of spontaneous circulation (ROSC). Cardiac arrest for 4 min caused a prolonged (60 min) reduction of blood flow in jejunal wall, muscle and brain as determine…
TREATMENT WITH SILDENAFIL PREVENTS IMPAIRMENT OF LEARNING IN RATS BORN TO PRE-ECLAMPTIC MOTHERS
2010
Pre-eclampsia is an important hypertensive pregnancy disorder and a main cause of maternal and fetal morbidity and mortality Children born from mothers with preeclampsia may present cognitive deficits The mechanisms leading to this cognitive impairment remain unclear and no treatments to improve it have been tested Pre-eclampsia is associated with impaired regulation of the nitric oxide 3 5 guanosine monophosphate cyclic (cGMP) pathway, which modulates some cognitive functions We hypothesized that alterations in the NO-cGMP pathway would be involved in the mechanisms leading to cognitive impairment in rats born to pre-eclamptic mothers and that treatment with sildenafil an inhibitor of the …
Influence of prenatal exposure to environmental pollutants on human cord blood levels of glutamate
2013
El pdf del artículo es la versión post-print.
A single mutation in the recombinant light chain of tetanus toxin abolishes its proteolytic activity and removes the toxicity seen after reconstituti…
1994
Specific proteolysis by the tetanus toxin light chain of a vesicle-associated membrane protein (VAMP) involved in exocytosis is thought to underlie its intracellular blockade of neurotransmitter release. To substantiate this mechanism, recombinant light chain was expressed as a maltose binding protein-light chain fusion product in Escherichia coli. After purification of affinity chromatography and cleavage with factor Xa, the resultant light chain was isolated and its identity confirmed by Western blotting and N-terminal sequencing. It exhibited activity similar to that of the native light chain in proteolyzing its target in isolated bovine small synaptic vesicles and in hydrolyzing a 62-re…
Metabotropic glutamate receptors activate phospholipase D in astrocytes through a protein kinase C-dependent and Rho-independent pathway.
2003
Metabotropic glutamate receptors (mGluRs) are G protein-coupled receptors that mediate phospholipase D (PLD) activation in brain, but the mechanism underlying this response remains unclear. Here we used primary cultures of astrocytes as a cell model to explore the mechanism that links mGluRs to PLD. Glutamate activated both phospholipase C (PLC) and PLD with equal potency and this effect was mimicked by L-cysteinesulfinic acid, a putative neurotransmitter previously shown to activate mGluRs coupled to PLD, but not PLC, in adult brain. PLD activation by glutamate was dependent on Ca(2+) mobilization and fully blocked by both protein kinase C (PKC) inhibitors and PKC down-regulation, suggesti…