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

In the subcommissural organ (SCO) of the guinea pig, rat, golden hamster, and mouse the activity and distribution of enzymes related to the energy-supplying metabolism and of some marker enzymes of different cell organelles have been investigated by means of mostly modified histochemical methods. The results were compared with findings in the ciliated ependyma of the ventricular wall and with those in the ependyma of the choroid plexus of the third ventricle. In the ependymal part of the SCO only a moderate activity of hexokinase is observed in its specialized columnar cells whereas a high activity is present both in the ciliated ependyma and the choroid plexus. - The staining pattern of glucose-6-phosphatase is similar to that of hexokinase but this enzyme is found is the SCO only. - Likewise hexokinase, glycogen granules and enzymes related to glycogen metabolism (phosphoglucomutase, uridine-diphosphoglucose pyrophosphorylase, glycogen synthetase and phosphorylase) are regularly found most numerous and active in the nuclear and supra-nuclear area of the ependymal part. These enzymes are less active in both the other ependymal regions. - Uridine-diphosphoglucose dehydrogenase could not be demonstrated in the SCO. The NADP-linked enzymes of the pentose phosphate shunt, glucose-6-phosphate and 6-phosphogluconate dehydrogenase, show a moderate activity which decreases also from the nuclear towards the apical area of the ependymal cells of the SCO. Enzymes of the glycolytic pathway, such as glucosephosphate isomerase, fructose-6-phosphate kinase, fructose-I,6-diphosphate aldolase, glyceraldehyde-3-phosphate and lactate dehydrogenase, are highly active in the SCO and are located mainly in the supranuclear area, too. Fructose-1,6-diphosphatase could not be demonstrated thus indicating that in the SCO the pathway is most probably only glycolytic but not gluconeogenetic. Compared to the ependyma of the ventricular wall and of the choroid plexus, in the SCO the M type subunits of lactate dehydrogenase predominate. Glycolytic enzymes are also very active in the choroid plexus but less in the ciliated ependyma. Compared to the ciliated ependyma and especially to the ependyma of the choroid plexus, the activities of enzymes which are only present in mitochondria (NAD-linked isocitrate dehydrogenase, succinate dehydrogenase, NAD-linked malate dehydrogenase after preextraction, cytochrome oxidase, 3-hydroxybutyrate and glycerolphosphate and glutamate dehydrogenase) are relatively low. Mitochondria are accumulated near the superior pole of the nuclei as well as in the most apical part of the ependymal cells. - The staining pattern of NADP-linked isocitrate and malate dehydrogenase as well as of NADH dehydrogenase suggests that these enzymes are localized both in and out of mitochondria. The extramitochondrial activity of the first two enzymes might be localized in the cytosol. The extramitochondrial activity of NADH dehydrogenase might be localized in the endoplasmic reticulum...
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PMID:Enzymatic organization of the subcommissural organ. 123 49

The food intake, gut weight, gut length, mucosal protein and mucosal activities of alkaline phosphate (EC 3.1.3.1), acid phosphate (EC 3.1.3.2), isocitric dehydrogenase (EC 1.1.1.42) and glucose-6-phosphate (EC 3.1.3.9) were measured in rats during pregnancy, lactation and after the young were weaned. In general, the quantities measured increased slightly during pregnancy and considerably during lactation, reaching maximum values during the 3rd weeks of lacation and falling more or less rapidly after the young were weaned to the same levels as those in unmated animals. However, the gut length and mucosal protein remained higher even 3 weeks after weaning, so that weight per unit length and specific enzyme activities (per mg protein) tended to be lower in mated than in unmated rats. Changes in the specific activities of enzymes indicate alterations of the metabolic function of the enterocytes during breeding similar to changes reported for digestive enzymes. It is suggested that the intestine may reflect changes that take place in the liver.
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PMID:Activities of some metabolic enzymes in the small intestinal mucosa during pregnancy and lactation in the rat. 625 36

The metabolic enzymes alkaline phosphatase (EC 3.1.3.1), acid phosphatase (EC 3.1.3.2) and isocitrate dehydrogenase (EC 1.1.1.42) were measured in mucosal homogenates and these enzymes, together with glucose-6-phosphatase (EC 3.1.3.9), were measured in homogenates of isolated enterocytes from germ-free (GF) and conventional (CV) chicks which were either fed continuously until they were killed or were subjected to a 16 h fast before killing. The intestine of the GF chicks was generally lighter than that of the CV controls. The activity of alkaline phosphatase was greater in the mucosal homogenates of the CV chicks compared with the GF birds, but the concentrations of acid phosphatase and isocitric dehydrogenase were not different in the two groups. In the isolated enterocytes the concentration of all enzymes expressed per mg DNA, except alkaline phosphatase, was higher in the GF chicks. Expressed per mg protein there was no significant difference in enzyme activity in the two groups. Fasting caused a reduction in intestinal weight and total mucosal protein in both groups but the reduction was greater in the GF chicks compared with the CV controls. In the GF chicks, fasting caused a significant fall in acid phosphatase and isocitric dehydrogenase activities of the mucosal homogenate, whereas in the CV chicks only acid phosphatase fell to a significant extent. In the isolated enterocytes feeding caused a marked fall in protein per mg DNA in the CV chicks; fasting tended to reduce enzyme concentrations in the GF chicks but to have less effect in the CV group except for alkaline phosphatase where there was a marked rise in activity. It is suggested that the difference in enzyme activities in the mucosal homogenates and isolated enterocytes might resulted from (a) the presence of a much greater lamina propria in the CV compared with the GF chicks and (b) the greater mitotic activity in the fed CV chicks yielding a much larger number of smaller immature cells.
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PMID:The activities of some metabolic enzymes in the intestines of germ-free and conventional chicks. 663 33