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 order to evaluate the possible role of sodium- and potassium-activated adenosine triphosphatase in the active transport of sodium by the renal tubules, we examined the effect of large changes in the tubular reabsorptive load of sodium on the Na-K-ATPase activity of rat kidney homogenates. Glomerular filtration and tubular reabsorption of sodium per gram of kidney tissue increased progressively after contralateral uninephrectomy. This was paralleled by an increase in Na-K-ATPase per milligram of protein in a microsomal fraction of kidney cortex. The importance of this change is underlined by the absence of simultaneous increases in other microsomal enzymes such as glucose-6-phosphatase and Mg(++)-dependent ATPase, or in succinic dehydrogenase or glutaminase. Similar increases in Na-K-ATPase were observed when the net tubular reabsorption of sodium was increased by feeding the animals a high-protein diet or after injection of methylprednisolone. On the other hand, Na-K-ATPase was lowered when tubular transport of sodium was reduced by bilateral adrenalectomy. The results of these experiments show that renal Na-K-ATPase changes in an adaptive way when renal reabsorption of sodium is chronically increased or diminished and support the hypothesis that this enzyme system is involved in the process by which sodium is actively transported across the renal tubule.
 ...
PMID:The role of sodium-potassium-activated adenosine triphosphatase in the reabsorption of sodium by the kidney. 429 72

The activity of sodium-potassium-activated adenosine triphosphatase (Na-K-ATPase) is considerably higher in homogenates of outer medulla than in the cortex or papilla of the kidney. The enzyme has similar kinetic characteristics in both cortex and medulla, and binds ouabain in the same proportion. The discrepancy in enzymatic activity is not paralleled by similar change in the activity of adenyl cyclase, 5'nucleotidase, glucose-6-phosphatase, or succinic dehydrogenase. Na-K-ATPase is also higher in distal convoluted tubules (ventral slices) than in the proximal tubules (dorsal slices) of the kidney of Amphiuma. The high concentration of Na-K-ATPase in the red medulla of the kidney is probably related to the presence here of the thick ascending limb of the loop of Henle, and this has important implications with regard to the mechanism of sodium reabsorption by different portions of the nephron.
 ...
PMID:The distribution of sodium-potassium--activated adenosine triphosphatase in medulla and cortex of the kidney. 432 13

Phagocytic vesicles were obtained by density gradient centrifugation of homogenized rabbit alveolar macrophages that had ingested emulsified paraffin oil contained Oil Red O. The phagocyte vesicles floated and thereby were separated from the soluble fraction and from other cell components which sedimented. The purity of the isolated vesicles was documented by electron microscopy, chemical and enzyme analysis. The vesicles contained 87% of the cell-associated Oil Red O, and were essentially free of DNA, RNA, succinic dehydrogenase, and glucose-6-phosphatase. Acid phosphatase, beta-glucuronidase, and catalase were transferred from the sedimenting fraction to the phagocytic vesicle fraction during phagocytosis, whereas enzyme activities of the soluble fraction remained unchanged. Half of the catalase of resting macrophages was in the pellet fraction and, compared with acid phosphatase, greater amounts of digitonin were required to release full activity. Such differential latency has been described for enzymes of peroxisomes vs. those of lysosomes. Compared with polymorphonuclear leukocyte vesicles studied previously, phagocytic vesicles of macrophages had more electron-dense material and lower Oil Red O:protein, phospholipid:protein, and enzyme:protein ratios. It is thus probable that secondary lysosomes become part of the macrophage vesicle. When paraffin oil particles, the stimulus for phagocytic vesicle formation, were washed away from the macrophages, acquisition of hydrolases by preformed vesicles ceased, i.e. transfer of these enzymes into phagocytic vesicles occurred only during or shortly after the formation of new vesicles. As noted previously by others, the content of acid hydrolases of stimulated alveolar macrophages was doubled in comparison to normal cells. The difference between stimulated and normal macrophages was even more marked when isolated phagocytic vesicles were analyzed. Vesicles from stimulated macrophages had 3-5 times more enzyme activity (per milligram of vesicle protein or per amount of paraffin oil ingested) than did vesicles from normal cells.
 ...
PMID:Isolation and properties of phagocytic vesicles. II. Alveolar macrophages. 501 Nov 3

Enzyme histochemical methods were performed on sporozoite infected liver tissue of rats in order to gain insight into the nutrition and metabolism of exoerythrocytic forms of Plasmodium berghei. The following enzymes were demonstrated in the hepatocytic stages of the parasites, obtained 41 and 48 h after inoculation of sporozoites: acid phosphatase, cytochrome oxidase, NADH-tetrazolium reductase, succinate dehydrogenase, NAD+ and NADP+ dependent isocitrate dehydrogenase, NADP+-dependent malate dehydrogenase, lactate dehydrogenases, 6-phosphogluconate dehydrogenase and glucose-6-phosphate dehydrogenases and alpha-glycerol-phosphate dehydrogenase. The results suggest that a conventional Embden-Meyerhoff pathway, pentose phosphate pathway and Krebs' citric acid cycle may in part be present in these exoerythrocytic parasites. Alkaline phosphatase, nucleoside polyphosphatase, 5' nucleotidase, glucose-6-phosphatase, alpha-glucan phosphorylase, NAD+ dependent malate dehydrogenase, amino-peptidase M and non-specific esterases were not detected by our techniques in the parasite. The enzyme distribution of this intrahepatocytic malaria parasite revealed by histochemistry is compared with the enzyme distribution in the other phases of the parasite's life cycle.
 ...
PMID:Histochemical observations on the exoerythrocytic malaria parasite Plasmodium berghei in rat liver. 608 94

The freshwater murrel, Channa punctatus, was exposed to a sublethal concentration of mercuric chloride (3 micrograms/liter) for 120 days and the following effects were examined: changes in the levels of glucose and lactic acid in blood and of glycogen and lactic acid in liver and muscles; rate of absorption of glucose from the intestine; and changes in the activities of glucose-6-phosphatase (G-6-Pase), hexokinase, lactate dehydrogenase (LDH), pyruvate dehydrogenase (PDH), succinate dehydrogenase (SDH), malate dehydrogenase (MDH), glutamate dehydrogenase (GDH), L-amino acid oxidase (AO), and xanthine oxidase (XO) in brain, gills, intestine, kidney, liver, and muscles. Mercury-treated fish were hypoglycemic and hypolactemic. The glycogen content of liver and muscles remained unaltered but the muscle lactic acid level decreased significantly. The rate of intestinal absorption of glucose was reduced significantly by exposure to mercury. G-6-Pase activity was decreased in all the tissues. Hexokinase activity also decreased in mercury-exposed fish but it was significant only in intestine, kidney, and liver. The activities of LDH, PDH, SDH, and MDH also were decreased significantly except LDH in brain and MDH in kidney where an insignificant decrease and an insignificant increase, respectively, were recorded. GDH and AO activities were elevated in most of the tissues except GDH in gills, and AO in gills and muscles where a decrease was observed. XO activity in brain, gills, and kidneys was significantly elevated, but no marked alteration was noted in other tissues.
 ...
PMID:Effect of mercuric chloride on some biochemical and physiological parameters of the freshwater murrel, Channa punctatus. 608 7

We studied the morphologic appearance of alcoholic hyalin (AH)-containing hepatocytes in liver biopsies from 14 patients with alcoholic liver disease. Most hepatocytes had a characteristic appearance. The cells were swollen and hydropic with an intact cell membrane. The mitochondria had variable-sized cristae which were both shortened and elongated. The smooth endoplasmic reticulum was markedly decreased. The rough endoplasmic reticulum was bizarre, with detachment of the ribosomes that surrounded the AH. The hepatocytes that contained AH bodies had lost almost all the glucose-6-phosphate activity but had variable amounts of succinic dehydrogenase and diphosphopyridine nucleotide diaphorase activities. The neutrophils admixed with mononuclear cells attached themselves to the hepatocytes and then invaginated into the hepatocytic cytoplasm with focal lysis of the cell membrane mediated via the release of neutrophilic lysosomes. The distortion of protein-synthesizing organelles and decrease in glucose-6-phosphatase activity suggest that the AH-containing hepatocyte is metabolically decompensated. The final cell death may be related to the neutrophilic attack, rather than the metabolic derangement.
 ...
PMID:Alcoholic hyalin-containing hepatocytes--a characteristic morphologic appearance. 620 13

Out of 56 thioacetamide (TAA)-fed rats hepatocellular carcinoma were found in four instances after 300, 360, 450 and 495 days in the present experiment. Of the four tumours, two showed lung metastasis. The size of TAA-treated hepatocyte nucleoli increased greatly after several weeks of feeding. Two enzymes, succinate dehydrogenase and glucose-6-phosphatase were found in both cytoplasma and nucleoli of hepatocytes of which nucleolar localizations are quite new. In hepatocellular carcinoma, malignant cells lost glucose-6-phosphatase activity completely in cytoplasm and nucleoli though succinate dehydrogenase activity was present in these organelles.
 ...
PMID:Thioacetamide-induced hepatocarcinoma in rat. 626 62

In children with Reye's syndrome, liver specimens exhibit the following characteristics: mitochondrial dysfiguration, fatty infiltration, decreased activity of carbamyl phosphate synthetase and of ornithine transcarbamylase, histochemically reduced activity of succinic dehydrogenase and cytochrome oxidase, and depletion of glycogen. We intended to create an animal model for Reye's syndrome by treating mice with encephalomyocarditis virus, and/or salicylate, fructose, Atlox, butylated hydroxytoluene, pentachlorophenol, and an equal mixture of butylated hydroxytoluene and monosodium stearate. Liver specimens were then examined for the listed characteristics as well as for the activity of argininosuccinic lyase, arginase, phosphorylase, and glucose-6-phosphatase. Results of interest in regard to the experimental intention were obtained in livers of mice treated with virus and Atlox (A) or virus and butylated hydroxytoluene (B). In these specimens, we found a significant reduction (p less than 0.05)--except for ornithine transcarbamylase (A)--to the following levels (in percentage of normal mean): carbamyl phosphate synthetase (A, 79 per cent; B, 57 per cent); ornithine transcarbamylase (A, 91 per cent; B, 75 per cent); glycogen (A, 26 per cent; B, 37 per cent). Simultaneous morphologic analysis of these liver specimens indicated mitochondrial dysfiguration, absence of dense granules, fatty infiltration, and normal activity of succinic dehydrogenase and cytochrome oxidase. The induction of Reye's syndrome-like features in mouse liver may be useful for the study of disease mechanisms and therapy.
 ...
PMID:Reye's syndrome simulacra in liver of mice after treatment with chemical agents and encephalomyocarditis virus. 626 2

A simple method of analytical subcellular fractionation, combined with a sensitive computational method for data analysis and presentation, has been used to reinvestigate the distribution and relative amounts of several enzymes in the cytoplasmic and plasma membranes of two different cell types: one is a neoplastic, transformed cell type (Ehrlich ascites tumour cells), the other an untransformed, highly differentiated cell type (liver hepatocytes plus Kupffer and endothelial cells). In general the distribution of the enzymes in particular membranes is similar in the two cell types, however the relative amounts differ. Ehrlich ascites tumour cells have a higher specific activity of galactosyltransferase and ouabain-sensitive (Na,K)ATPase, while liver cells have higher glucose-6-phosphatase, 5'-nucleotidase and succinate dehydrogenase activity. These differences appear to be correlated with morphological and, in some cases, functional differences between the two cell types.
 ...
PMID:Comparison of Ehrlich ascites tumour and mouse liver cells by analytical subcellular fractionation combined with a sensitive computational method for data analysis. 626 22

The histochemical enzyme activity of alkaline phosphatase, nonspecific esterase, 5-nucleotidase, beta-glucuronidase, glucose-6-phosphatase, succinate dehydrogenase, and glucose-6-phosphate dehydrogenase in human bladder cancer was investigated. Tumors of 84 patients, classified into grades I-III according to the WHO classification, were compared with 12 normal and 16 inflamed bladder epithelia. As a rule, loss of alkaline phosphatase activity and a decrease of nonspecific esterase activity was found in most of these tumors. The activity of beta-glucuronidase was decreased and compared with normal tissue, also the activity of 5-nucleotidase. The succinate dehydrogenase activity in tumor tissue was frequently increased, whereas glucose-6-phosphate dehydrogenase did not show any significant reaction.
 ...
PMID:[Histochemical investigations on human bladder cancer (author's transl)]. 626 65


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>