Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.4.1.2 (glutamate dehydrogenase)
 4,380 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hepatic glutamate dehydrogenase (GDH) activity was measured in postmortem specimens obtained from two stage V Reye syndrome patients and in three postmortem specimens of normal human liver. The Reye syndrome specimens showed the hepatic mitochondrial enzyme deficits in GDH and monoamine oxidase activities that are characteristic of Reye syndrome. GDH activity was linear with the amount of supernatant fraction added, both for Reye and normal liver preparations: moreover, the activities of mixtures of Reye and control supernatant fractions were the sums of the activities of the individual components. This means that the activity difference between Reye and normal GDH activity is not due to a diffusible inhibitor in the Reye hepatocytes or to an activator of GDH in the normal control hepatocytes. Serum obtained from six Reye cases during neurologic deterioration was added to normal hepatic GDH preparations to test for a serum inhibitor of FDH. Highly variable effects were found, with two serum samples producing marked inhibition and others showing weak inhibition, no effect, or stimulation of GDH activity. The inhibitor was not removed by charcoal treatment and most of the activity was retained by a 10,000 dalton Diaflo membrane, signifying either that the compound had a high molecular weight or that it was bound to serum protein. We conclude that the decreased activity of GDH in Reye hepatocytes is not due to an intracellular diffusible inhibitor, and that serum effects are quite variable and are not directly related to intracellular changes in GDH activity.
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PMID:Absence of diffusible inhibitor of glutamate dehydrogenase in the hepatocytes of Reye syndrome patients. 396 1

Five enzymes were measured in 50 liver specimens (18 normal liver, 20 Reye liver, 12 diverse liver disorders other than Reye syndrome). The enzymes were: glutamic dehydrogenase (E.C. 1.4.1.3), monoamine oxidase (E.C. 1.4.3.4), lactate dehydrogenase (E.C. 1.1.1.27), D-glucose-6-phosphate dehydrogenase (E.C. 1.1.1.49), catalase (E.C. 1.11.1.6). The Reye syndrome group showed significant decreases in glutamic dehydrogenase (56%) and monoamine oxidase (70%) compared to normal control tissue and these changes were not characteristic of the non-Reye liver disorder group as a whole. Neither catalase nor lactate dehydrogenase appeared to be altered significantly in the Reye or in the abnormal control group compared with normal controls. Thus, only the prominent decreases in the mitochondrial enzyme activities appeared to be highly characteristic of Reye syndrome. Paradoxically, the means of the five hepatic enzymes and the admission levels of two serum enzymes indicative of liver damage (alanine and aspartate aminotransferase) were remarkably similar for both survivors and nonsurvivors of Reye syndrome.
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PMID:Quantitative evaluation of the extent of hepatic enzyme changes in Reye syndrome compared with normal liver or with non-Reye liver disorders: objective criteria for animal models. 396 10

Serum glutamate dehydrogenase (GDH) activity was greatly raised (up to 830 times the upper limit of normal) in 16 patients with Reye's syndrome. The serum activity was masked by an inhibitor, and the rises were observed only after dialysis or sample dilution. Serum GDH values from 38 paediatric patients, including 10 with hyperammonaemia due to other causes, showed no such rise after dialysis. Only 1 of 13 adult patients with liver disease had high GDH activity, but this level was not increased after dialysis. Serum ornithine carbamyl transferase activity was also raised in patients with Reye's syndrome, but levels were not increased after dialysis. The ratio of dialysed/undialysed GDH activity clearly distinguished all Reye's patients from controls. The inhibition of a mitochondrial enzyme which regulates ammonia metabolism may contribute to the hyperammonaemia of Reye's syndrome. Serum GDH levels before and after dialysis would seem to be a useful diagnostic aid in Reye's disease.
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PMID:Masking by enzyme inhibitor of raised serum glutamate dehydrogenase activity in Reye's syndrome. 613 99