glutaminase/edema

There is compelling evidence that initiation and maintenance of epileptic seizures in temporal lobe epilepsy (TLE) is facilitated by excessive accumulation in the extracellular (perisynaptic) space of the excitatory neurotransmitter glutamate (Glu). This review discusses the mechanisms underlying

Glutamine synthesis and utilization were studied in the plantaris muscle after removal of its functional synergists, the soleus and gastrocnemius muscles. Rat plantaris muscle was compared with unoperated controls at 7, 14, and 30 days after synergist ablation and induction of hypertrophy. Glutamine

Glutamine (Gln) abounds in the central nervous system (CNS), and its interstitial and cerebrospinal fluid (CSF) concentrations are at least one order of magnitude higher than of any other amino acid. Gln transport from blood to the brain is insufficient to meet the demand of the brain tissues for

Ineffective hepatic clearance of excess ammonia in the form of urea, as occurs in urea cycle enzymopathies (UCDs) and in liver failure, leads to increases in circulating and tissue concentrations of glutamine and a positive correlation between brain glutamine and the severity of neurological

Free ammonium ions are produced and consumed during cell metabolism. Glutamine synthetase utilizes free ammonium ions to produce glutamine in the cytosol whereas glutaminase and glutamate dehydrogenase generate free ammonium ions in the mitochondria from glutamine and glutamate, respectively.

Brain edema and the subsequent increase in intracranial pressure are the major neurological complications in fulminant hepatic failure (FHF). Brain edema in FHF is predominantly "cytotoxic" due principally to astrocyte swelling. It is generally believed that ammonia plays a key role in this process,

Mechanisms involved in hepatic encephalopathy still remain to be defined. Nonetheless, it is well recognized that ammonia is a major factor in its pathogenesis, and that the astrocyte represents a major target of its CNS toxicity. In vivo and in vitro studies have shown that ammonia evokes