Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.9 (glucose-6-phosphatase)
 3,081 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Palmitate, glucose, and glycerol oxidation to CO(2) have been investigated in the fasted state in ten normal subjects and nine patients (six hyperlipoproteinemias, one xanthomatosis, and two glycogenosis) after intravenous injection of [1-(14)C]palmitate, [1-(14)C]glucose, or [1-(14)C]glycerol in tracer amounts. The specific activities and concentrations of plasma palmitate, glycerol, or glucose and expired CO(2) were measured at various intervals after the injection for a period of 24 h. All the studies were analyzed in terms of a multicompartment model describing the structure for each of the subsystems, the transfer of carbon label between subsystems, and the oxidation to CO(2). A bicarbonate subsystem was also included in the model to account for its role in shaping the CO(2) curves. All the CO(2) activity following a palmitate injection could be accounted for by a direct oxidative pathway from plasm FFA with the addition of a 20-min delay compartment. The same also applied to glucose, except that the delay compartment had a mean time of about 150 min. Only about a third of the injected glycerol was directly oxidized to CO(2) from plasma; the delay time was about 4 min. Most of the remainder was converted to glucose. In normals about 45% of the FFA is oxidized to CO(2) directly. This constitutes about 30% of the total CO(2) output. In hyperlipemia the CO(2) output is nearly unchanged and the contribution from FFA is nearly the same. There is a considerable increase (factor of 2), however, in FFA mobilization, most of which is probably diverted to triglyceride synthesis. The glucose and glycerol subsystems are roughly the same in normals and hyperlipemics. About 50% of glucose is oxidized by the direct pathways which accounts for about 35% of the CO(2) output. Glycerol accounts for only 1.5% of the CO(2) produced. Major changes occurred in the glycerol and glucose subsystems in glycogenosis. The changes are consistent with the known deficiency in glucose-6-phosphatase in this disorder. There is a considerable reduction (factor of 2 or more) in the release of glucose to plasma (gluconeogenesis) and in the conversion of glycerol to glucose. Despite the integration of the kinetics of the glucose, glycerol, and FFA subsystems over a 24-h period, 36% of the CO(2) production was still unaccounted for in normals and 50% in hyperlipemics. Thus, some of the carbon must wind up in very slowly turning-over pools which supply CO(2) through subsystems not covered in these studies (triglycerides, glycogen, amino acids, etc.). All the modeling was carried out with the aid of the SAAM25 computer program.
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PMID:Interrelations in the oxidative metabolism of free fatty acids, glucose, and glycerol in normal and hyperlipemic patients. A compartmental model. 452 90

Glycogen storage diseases (GSDs) or glycogenoses comprise several rare inherited diseases caused by abnormalities of the enzymes that regulate the synthesis or degradation of glycogen. We report on a male patient with type Ia GSD (GSD Ia) who was followed-up for more than 20 years. He had been diagnosed with GSD Ia based on biochemical tests and the glucose-6-phosphatase (G6Pase) enzyme assay from a liver biopsy at 6 years old, due to problems of hepatomegaly, growth retardation, and recurrent hypoglycemic episodes. The introduction of uncooked cornstarch improved his quality of life only in the first 8-year follow-up period. At 17 years old, gouty arthritis with multiple tophi and generalized xanthomatosis developed. Later, hepatocellular adenoma, nephrolithiasis, and gastrointestinal bleeding occurred at the age of 20, 23, and 24 years, respectively. At 26 years old, he suffered from acute renal failure and polyradiculoplexopathy. The problem of delayed puberty persisted. The story of this patient illustrates the multisystemic nature of GSD Ia and highlights the need for careful dietary therapy and long-term follow-up.
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PMID:A 20-year follow-up of a male patient with type Ia glycogen storage disease. 1284 28