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)

A deficiency of extramitochondrial form of hepatic phosphoenolpyruvate carboxykinase has been demonstrated in a boy with severe, persistent neonatal hypoglycaemia. Hepatic glucose-6-phosphatase, fructose-1.6-diphosphatase and pyruvate carboxylase were normal. The total activity of phosphoenolpyruvate carboxykinase was also normal, but the enzyme showed an abnormal subcellular distribution, virtually no activity being detected in the extramitochondrial fraction of a liver homogenate. The boy died at the age of 2 years 10 months. Autopsy revealed severe cerebral atrophy, atrophy of the optic nerve, and fatty infiltration of liver and kidney.
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PMID:Gluconeogenesis in infancy and childhood. III. Deficiency of the extramitochondrial form of hepatic phosphoenolpyruvate carboxykinase in a case of persistent neonatal hypoglycaemia. 17 69

The activities of key gluconeogenic enzymes in the liver of newborn guinea pigs delivered vaginally at term were monitored as a function of time following birth. The activities of glucose-6-phosphatase and fructose-1,6-diphosphatase did not show a significant increase over the first 72 h of life, neither did the activity of mitochondrial phosphoenolpyruvate carboxykinase. The mitochondrial enzyme pyruvate carboxylase and the cytosolic phosphoenolpyruvate carboxykinase (PEPCK) both increased significantly in the first 24 h postpartum. Mitochondrial protein and succinate dehydrogenase activities showed only slight increases in the 72-hour period. Rapid depletion of liver glycogen was evident in these animals following birth, but severe hypoglycaemia was not evident. Mitochondrial and cytosolic PEPCK showed similar kinetic behaviour with respect to their affinities for oxalacetate and divalent metal cation Mn++, though the mitochondrial enzyme would accept Mg++ as the divalent metal in place of Mn++. The role of the compartmented PEPCK activities is discussed.
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PMID:Development of gluconeogenic enzymes in the newborn guinea pig. 17 23

The activities of key gluconeogenic enzymes in the livers of newborn guinea pigs were monitored as a function of time following birth either vaginally at term or prematurely by cesarian section at 62 days of gestation. The activity of hepatic glucose-6-phosphatase rose dramatically from 1.40 +/- 0.26 mumol/min/g at birth to a maximum of 6.8 +/- 0.9 mumol/min/g at 24 hr in prematurely delivered animals although there was little significant change in activity in full term animals. The activity of hepatic fructose-1,6-diphosphatase and mitochondrial phosphoenolpyruvate carboxykinase changed little over the first 3 days of life in either full term or premature animals. Cytosolic phosphoenolpyruvate carboxykinase, on the other hand, had low activity at birth being 0.11 +/- 0.03 mumol/min/g in full term and 0.06 +/- 0.04 mumol in premature animals rising to values of 0.71 +/- 0.06 and 1.12 +/- 0.12 mumol/min/g, respectively, at 24 hr of life. Pyruvate carboxylase activities in the premature animals remained significantly lower than those in full term animals in the first 72 hr of life. Transient hypoglycemia was evident in the prematurely delivered animals, but not in the full term animals, the blood glucose values being 82 +/- 7 mg/100 ml for the full term animals and 20 +/- 8 mg/100 ml for the premature infants at 2 hr of life.
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PMID:The effect of premature delivery on the development of gluconeogenic enzymes in the guinea pig. 18 25

Congenital enzymopathic hyperlactacidemia results from a defect of utilisation of pyruvate either at the level of the pyruvate junction (pyruvate-carboxylase, pyruvate-dehydrogenase and Kreb's cycle), or at the level of the unidirectional enzymes on neo-glucogenesis and of neo-glycogenogenesis, e.g. glucose-6-phosphatase, phosphoenol-pyruvate-carboxykinase and glycogen synthetase. The enzymopathies which affect neoglucogenesis associate hyper-lactacidemia and fasting hypoglycemia and more or less marked hepatomegaly. Type I glycogenesis (von Gierke's disease) is the best known example. Enzymopathies which affect the pyruvate junction and the Krebs cycle, may be manifested in addition by: --either chronic neuropathies, e.g. Leigh's disease, recurrent ataxia, and moderate hyperalactacidemia,--or, as in congenital lactic acidoses, which have a rapid and severe prognosis with major hyperlactacidemia. Functional investigation, in particular, loading tests are of great value in orientation and justify the practice of tissue biopsy which permits the enzyme diagnosis. Recent, still unconfirmed knowledge of the pathogenesis of these diseases emphasizes the considerable importance of estimation of blood lactic acid in the investigation of metabolic acidoses of hereditary origin.
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PMID:[Enzymopathic congenital hyperlactacidemia]. 18 25

In glycogenosis type 1 (GT1), glucose synthesis is deficient due to absence of glucose-6-phosphatase. Development of renal failure in such a patient provided the opportunity to test whether or not this metabolic defect could be reversed by a renal allograft, which contains the missing enzyme and has potential for glucose synthesis. Despite normalization of renal function and both glucocorticoid therapy and the infusion of amino-acid precursors of glucose, fasting hypoglycemia persisted unabated. We conclude that a funtioning renal allograft is incapable of meeting the metabolic demands of a patient with glucose-6-phosphatase deficiency.
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PMID:Renal tranplantation in type 1 glycogenosis. Failure to improve glucose metabolism. 20 6

An adult woman with hypoglycemia, hyperlactatemia, hyperuricemia, hypertriglyceridemia, hyperketonemia and inability to make new glucose from galactose, fructose, glycerol and alanine was found to have no hepatic glucose-6-phosphatase and deficient fructose-1,6-diphosphatase. Nonautonomous hyperglucagonemia was demonstrated and shown to contribute to the hyperlactatemia and hyperketonemia. A paradoxic hyperlactatemic response to glucose and galactose was observed. Studies of substrate utilization showed prompt adaptation to changes in dietary supply of energy which probably accounted for her never having experienced symptoms of hypoglycemia.
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PMID:Combined deficiency of glucose-6-phosphatase and fructose-1, 6-diphosphatase. Studies of glucagon secretion and fuel utilization. 20 39

The classical features of Type I glycogen storage disease (McKusick 23220) (GSD) are hepatomegaly, hypoglycaemia, and acidosis, enlargement of the kidneys and short stature. Glucose-6-phosphatase (EC 3.1.3.9) activity is defective not only in liver and kidney but also in small intestine (Field et al., 1965). In addition to the classical features, many patients suffer from episodes of diarrhoea (Fine et al., 1969). At the Hospital for Sick Children, Great Ormond Street, patients with the commoner forms of hepatic glycogen storage disease have episodes of diarrhoea or loose stools more commonly than was suspected. We have investigated small intestinal function in three patients with Type I GSD by both in vitro and in vivo techniques.
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PMID:Disordered intestinal function in glycogen storage disease. 22 44

The activities of two gluconeogenic enzymes, glucose-6-phosphatase and fructose-1,6-diphosphatase were examined in the normal and intrauterine growth retarded (IUGR) rat during the first 5 days of life. The fructose-1,6-diphosphatase activity, 1.54 +/- 0.10 mumol/min/g liver (means +/- SEM) in control and 1.47 +/- 0.20 in the IUGR rats, increased in both groups on days 2--4 but remained significantly lower in the IUGR rats through day 4 (4.53 +/- 0.6 mumol/min/g liver in control and 3.09 +/- 0.22 mumul/min/g liver in the IUGR rats, P less than 0.01). The glucose-6-phosphatase activity increased similarly in both groups. The weight of the IUGR rats remained lower through the third postnatal day (6.47 +/- 0.42 compared to 8.64 +/- 0.27 g in control rats). Blood glucose concentrations at birth were 117 +/- 11 mg/dl in control rats and 73 +/- 11 mg/dl in the IUGR rats (P less than 0.01). Although the glucose concentrations increased in both groups on days 2--4, the IUGR rats maintained relatively lower levels (P less than 0.01). The results indicate that IUGR fetal rats do not have augmented gluconeogenesis in spite of hypoglycemia. In addition, effective gluconeogenesis in the neonatal period appears to be delayed.
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PMID:Fructose-1,6-diphosphatase and glucose-6-phosphatase in newborn rats with intrauterine growth retardation. 23 Sep 54

Intrauterine growth retardation was induced in rats by ligation of the artery of one of both uterine horns. Activities of pyruvate carboxylase, phosphoenolpyruvate carboxykinase, fructose-1,6-diphosphatase and glucose-6-phosphatase in liver were measured at 0, 1, 3 and 6 h after delivery in newborn rats from normal and sham-operated litters, and from ligated and contralateral uterine horns. Lower activities of fructose-1,6-diphosphatase were found in small-for-gestational-age animals in comparison with animals from contralateral horns. When small-for-gestational-age animals were compared with animals from sham litters (which could be regarded as more satisfactory controls), the activities of two other gluconeogenic enzymes (pyruvate carboxylase and glucose-6-phosphatase) appeared to be lower as well. It is concluded that a delay in the development of these gluconeogenic enzymes could play a role in neonatal hypoglycemia in small-for-gestational-age rats.
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PMID:Gluconeogenic key enzymes in normal and intrauterine growth-retarded newborn rats. 23 14

Two patients are described with chronic hypoglycaemia; the first having glucose-6-phosphatase deficiency (type I glycogen storage disease), and the second fructose 1:6-diphosphatase deficiency. Both cases were associated with a bleeding diathesis, a defect of platelet aggregation, and a deficiency of platelet adenine nucleotides. The effect on the platelet abnormalities of a period of normoglycaemia was studied in both patients. Correction of the platelet abnormalities occurred rapidly after stabilization of the blood glucose within the normal range. Normal function persisted for the duration of the normoglycaemia, facilitating diagnostic liver biopsy and surgical procedures. A biochemical explanation for the nucleotide deficiency is suggested.
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PMID:Defect of platelet function associated with chronic hypoglycaemia. 94 29


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