Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

When rat pancreatic islets were incubated in the presence of unlabelled D-glucose (16.7 mM) and 3HOH, the production of 3H-labelled material susceptible to be phosphorylated by yeast hexokinase and then detritiated by yeast phosphoglucoisomerase did not exceed 2.66 +/- 0.21 pmol/islet per 180 min, i.e. about 1% of the rate of exogenous D-[5-3H]glucose utilization. Such a material accounted for 43 +/- 4% of the total radioactivity, associated with tritiated hexose(s). It is proposed, therefore, that the futile cycling of D-glucose in the reactions catalyzed in the islet cells by the hexokinase isoenzymes and glucose-6-phosphatase represents a negligible fraction of the total rate of D-glucose phosphorylation.
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PMID:Hexose metabolism in pancreatic islets. Insignificance of D-glucose futile cycling in rat islets. 165 83

Thirty male rats were grouped into 5 groups of 6 animals each. Animals in groups II-V were given gossypol at a dose of 5 mg/kg, 10 mg/kg, 20 mg/kg and 40 mg/kg body weight per day for 45 days respectively. Animals of group I served as control. A significant decrease in body weight after administration of 40 mg/kg body weight of gossypol was observed; low doses of gossypol, however did not affect the body weight. Testis, epididymis, prostate and seminal vesicles weights decreased gradually with the increasing doses of gossypol. With the increasing doses of gossypol, a marked decrease in the vas deferens sperm motility was observed. At 40 mg/kg dose there was a total inhibition of sperm motility. Histological studies after 5 mg/kg revealed no apparent sign of degeneration, while after 10 mg/kg dose the changes in the individual cell types were accompanied by overall disorganisation of the germinal epithelium involving displacement of the spermatocytes. The rats treated with 20-40 mg/kg gossypol showed a pronounced deleterious effect on the histological structure of the testis. The drug effect was dose dependent developing sequentially; from the uppermost layer of elongated spermatids affecting round spermatids and finally spermatocytes. Quantitatively the ratios of pachytene spermatocytes: resting spermatocytes, stage 7 spermatids: pachytene spermatocytes, and stage 19 spermatids: stage 7 spermatids and tubular diameter and germinal height decreased significantly. The activities of glucose-6-phosphatase, fructose 1, 6-diphosphatase, glucose-6-phosphate isomerase in testis decreased significantly at high dose (40 mg/kg), while the activity of amylase and glycogen content increased significantly with the increasing doses of gossypol.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of gossypol on the fertility of male rats. 170 28

One hundred and five sexually mature male hamsters were divided in different groups. In the first experiment hamsters were administered gossypol, 10 mg/kg and 20 mg/kg/body weight/day, for twenty and thirty days. In the second experiment hamsters were administered gossypol, 5, 10 and 20 mg/kg/body weight/day, for sixty days. In the third experiment, hamsters were administered gossypol 5 mg, 10 mg, 20 mg and 40 mg/kg body weight/day for 45 days. Animals in all the groups were given gossypol by oral intubation every day. No significant effect on the body weight of hamsters following gossypol treatment was observed. At low doses the weights of testis and accessory sex organs were not statistically different from those of the controls. A significant decrease in testis and epididymis weight was however observed following high doses of gossypol. Low doses of gossypol treatment did not affect the motility of the vas deferens spermatozoa. The vas deferens spermatozoa were however immotile after 40 mg/kg/day gossypol treatment. Gossypol treatment induced a series of histological changes in the seminiferous epithelium of the hamster testis. The earliest sign of drug effect was seen in spermatids and with the increase in doses the effects became more pronounced and extended to the spermatocytes. At 40 mg/kg dose an almost complete arrest of spermatogenesis was observed. Quantitatively, the ratio of pachytene spermatocytes: resting spermatocytes and step 7 spermatids: pachytene spermatocytes decreased significantly. The step 7 spermatids did not mature to step 19 spermatids at all. Histochemically activities of ATPase, SDH and LDH decreased with the increasing doses of gossypol, the activity of 3B hydroxysteroid dehydrogenase was not affected by gossypol treatment. In testis the glucose-6-phosphatase activity was not affected significantly but the activities of fructose 1, 6-diphosphatase and glucose-6-phosphate isomerase decreased significantly with the increasing doses of gossypol. Amylase activity rose significantly at higher doses. Marked changes in LDH and LDH-X were however observed with the increase in gossypol dose. In liver the activity of glucose-6-phosphatase increased significantly while the activities of fructose 1, 6-diphosphatase, glucose-6-phosphate isomerase and amylase were not affected following gossypol treatment. The glycogen contents however increased significantly following high doses of gossypol. No changes in testosterone production and plasma levels of testosterone were observed following gossypol treatment.
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PMID:Response of hamster to the antifertility effect of gossypol. 170 27

Glycogen and protein concentrations and the activities of liver glycogen metabolic enzymes were measured in 22 children aged 4 to 15, suffering from extrahepatic portal hypertension. Glucose-6-phosphatase, amylo-1,6-glucosidase, fructose-1,6-diphosphatase, phosphorylases alpha and beta, phosphoglucomutase, and phosphohexose isomerase levels were analyzed. Liver biopsy specimens obtained by surgical marginal biopsy were used in the study. No or drastic reduction of phosphorylase alpha activity and reduction of glycogen concentration and glucose-phosphatase activity were found characteristic of extrahepatic hypertension. Analysis of correlations of the findings has demonstrated a medium correlation in 4 cases and a strong correlation between the findings in 1 case, the possibility being estimated as 0.95-0.99. The highest number of correlations was observed with phosphorylase alpha and glucose-6-phosphatase (3 correlations). Liver blood stream impairments result in injury to one of its main biochemical functions, i.e., the maintenance of blood glucose homeostasis, this leading to reduction of the adaptation potential of the body; this should be borne in mind when planning therapeutic measures for patients with extrahepatic hypertension.
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PMID:[Carbohydrate metabolism enzymes in children with extrahepatic portal hypertension]. 172 40

Biochemical changes in glycogen content and activity levels of phosphorylase (EC 2.4.1.1), glucose-6-phosphatase (EC 3.1.3.9), phosphohexose isomerase (EC 5.3.1.9) and aldolase (EC 4.1.2.13) have been studied in normal and denervated whole gastrocnemius muscle and its three fasciculi, viz., pars externus, medius and internus up to 9 weeks in chicks. Glycogen content as well as phosphorylase, phosphohexose isomerase and aldolase decrease in normal muscle with advancement of postembryonic growth whereas transiently increased glucose-6-phosphatase reveals an inverse relationship with these parameters. Denervated muscles demonstrate loss of glycogen and related enzymes owing to ablation of neural supply during the initial 4 weeks. Denervation results in a delayed stimulation of glycogenolysis and glycolysis which seems to be governed by decreasing activity of glucose-6-phosphatase. The significance of glucose-6-phosphatase in the regulation of glycogenolysis and glycolytic metabolism of normal and denervated skeletal muscle is discussed.
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PMID:Glucose-6-phosphatase activity in normal and denervated developing chick gastrocnemii: reappraisal of glycogenolytic and glycolytic metabolism in skeletal muscle. 301 90

Spermatogenically active testes of rat challenged by 100 mg/kg body weight of p- Chlorophenylalanine for 45 days displayed marked and drastic changes in the seminiferous epithelium. Degenerative changes followed by immense necrosis of germ cells lead to complete breakdown of seminiferous tubules. Leydig cells, however, remained unaffected histologically in the treated animals. Among the accessory sex organs, epididymis alone showed a marked decrease in its weight. A biochemical study in the drug treated rats revealed a significant accumulation of glycogen in the testes accompanied by increase in the activities of enzymes like the succinic dehydrogenase, glucose-6-phosphatase, ATP-ase and acid phosphatases. However, a marked decrease was noticed in the activities of enzymes like alkaline phosphatase, phosphohexose isomerase and lactate dehydrogenase. No significant change was found in the protein, DNA and RNA concentrations in the drug treated testes. The histological and biochemical changes induced in the testes by p-CPA suggest the deleterious effect of the drug on the seminiferous tubules of the testes.
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PMID:Effect of para-chlorophenylalanine on male rats: histopathological and biochemical changes in the testes. 303 Sep 34

Zinc, lead and cadmium in the form of chloride salts when added to a standard assay system containing 80 X 10(-6) ejaculated washed human spermatozoa caused a dose and duration-dependent inhibition of their motility. The activity of certain key enzymes of carbohydrate and energy metabolism, viz, glycogen phosphorylase, glucose-6-phosphatase, fructose-1, 6-diphosphatase, glucose-6-phosphate isomerase, amylase, Mg2+- dependent ATPase and lactic and succinic acid dehydrogenases were also found to be inhibited. The order of inhibitory effects of the heavy metals were zinc less than lead less than cadmium. The metal chelating agent, ethylene diamine tetra-acetic acid (EDTA, disodium salt) also interfered with the spermatozoal motility and inhibited the enzyme activities.
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PMID:Effect of selected metal ions on the motility and carbohydrate metabolism of ejaculated human spermatozoa. 314 74

The longitudinal localization of nine enzymes of the carbohydrate metabolism was studied in rats fed standard or high fructose diets, two months after a reciprocal jejuno-ileal transposition. In the ileal segment transposed to jejunal location, an adaptive increase of mucosal mass was observed, but the functional characteristics of enterocytes remained the same in the case of triokinase, aldolase, triose phosphate isomerase, glucose-6-phosphate isomerase and glucose-6-phosphatase activities. In the case of ketohexokinase and hexokinase activities, the functional properties of cells tended to resemble that of jejunum, as revealed by a significant increase in the specific enzyme activity. In the jejunum transposed to the place of the ileum, the fundamental properties of enterocytes and the functional capacity of the gut were maintained except in the case of fructose-1.6-bis phosphatase and of glucose-6-phosphatase. The high fructose diet did not facilitate the re-establishment of the gradient in its normal, aboral, direction. Indeed except for glucose-6-phosphatase, the enzymes of the jejunum transposed to the place of the ileum kept a high sensitivity and the enzymes of transposed ileum a low sensitivity to dietary fructose. Our conclusion is that the response to the diet depends more on the original position of the intestinal segment than on the local nutritional conditions and therefore that the basal activity of the majority of the intracellular enzymes implicated in carbohydrate metabolism and also their regulatory systems, are an intrinsic characteristic of the intestinal cells.
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PMID:[Intestinal adaptation and enzymatic changes following reciprocal jejunoileal transposition in rats. Effects of a high-fructose diet]. 397 35

Experiments were run on three groups of healthy guinea pigs. One group was given ethionamide, kanamycin and PASA another was given ethionamide, kanamycin and pyrazinamide while the third served as a control. These studies permitted to establish that the above drugs affect the activity of enzymes involved in the metabolism of carbohydrates and nucleic acids. Activity of glucose-6-phosphatase and aldolase significantly decreased in liver, brain and lung tissue. At the same time, activity of deoxyribonuclease and ribonuclease in the tissues concerned sharply increased. Changes in activity of phosphohexose isomerase, lactate dehydrogenase and aminotransferases in these tissues was statistically insignificant.
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PMID:[Effect of various combinations of antibacterial drugs on enzyme activity in guinea pig tissues]. 531 14

Liver cells obtained from newborn mice homozygous for any one of several overlapping deletions in chromosome 7 fail to express a number of liver-specific differentiated traits. Among these is the activity of the membrane-bound liver-specific enzyme glucose-6-phosphatase (Glc-6-Pase; D-glucose-6-phosphate phosphohydrolase, EC 3.1.3.9). Previous studies have led to the suggestion that the region of the genome covered by these deletions includes genes that normally regulate the expression of structural genes encoding liver-specific enzymes and proteins mapping elsewhere in the genome. To find out whether the deficiency of Glc-6-Pase may be caused by the deletion of the relevant structural gene, mouse liver cells homozygous for the deletion c14CoS were hybridized with 2S Faza rat hepatoma cells, and the hybrid cell cultures were analyzed for mouse and rat Glc-6-Pase activity. Hybrids showed expression of mouse Glc-6-Pase activity, proving that the structural gene for this enzyme is not included in the deletion c14CoS in chromosome 7. In the hybrid cells the rat hepatoma genome apparently contributes a factor that activates the structural gene of the mouse and corrects its failure of expression, which most likely resulted from the deletion of an essential regulatory or processing gene. By using as a marker glucose-6-phosphate isomerase (Glc-6-PIase; glucosephosphate isomerase, D-glucose-6-phosphate ketolisomerase, EC 5.3.1.9), known to map on chromosome 7, this entire chromosome could be excluded as a possible carrier of the Glc-6-Pase structural gene. In addition, the structural genes for Glc-6-Pase and for tyrosine aminotransferase (TyrATase; L-tyrosine:2-oxoglutarate aminotransferase, EC 2.6.1.5), another enzyme deficient in lethal deletion homozygotes, were shown to map on two different chromosomes. Together with our previous studies of TyrATase gene regulation, the present experiments suggest that the region of the mouse genome defined by the deletions includes one or more genes regulating the expression of several structural genes that map on different chromosomes and that encode liver-cell-type specific traits.
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PMID:Correction of a genetically caused enzyme defect by somatic cell hybridization. 657 48


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