Disease relevance of Ggt1

• Effect of coadministration of phenobarbital sodium on N-nitrosodiethylamine-induced gamma-glutamyltransferase-positive foci and hepatocellular carcinoma in rats [1].
• Almost all rats in group 3 had neoplastic nodules, gamma-glutamyltransferase-positive foci, adenofibrosis, and esophageal basal cell hyperplasia [2].
• The activity of gamma-glutamyltransferase, as measured quantitatively and by histochemical staining, was studied in different cell populations during the induction of liver cancer with 2-acetylaminofluorene (2-AAF) or diethylnitrosamine and compared with findings in fetal and in intact and regenerating adult liver [3].
• AT-125 blocked and glycylglycine potentiated DCVG toxicity, indicating that metabolism by gamma-glutamyltransferase is required [4].
• Different constructs for the expression of mammalian gamma-glutamyltransferase cDNAs in Escherichia coli and in Saccharomyces cerevisiae [5].

Psychiatry related information on Ggt1

• Hepatic gamma-glutamyltransferase activity: its increase following chronic alcohol consumption and the role of carbohydrates [6].
• gamma-Glutamyltransferase activity is unchanged in acutely quinolinate-lesioned rat neostriatum but is elevated in Huntington's disease caudate [7].

High impact information on Ggt1

• Lysine supplementation of wheat gluten during the postinitiation period enhanced the gamma-glutamyltransferase-positive response to a level comparable with that of the high-quality protein [8].
• Of the 11 nodules examined cytochemically, none was gamma-glutamyltransferase (gamma-GT) positive and 2 were positive to glucose-6-phosphate dehydrogenase (G-6-PD) under oxygen [9].
• The abilities of various pure polychlorinated biphenyls (PCB) and complex mixtures to generate resistant gamma-glutamyltransferase (GGT)-positive hepatocellular nodules was evaluated in F344 rats in which hepatocytes were proliferating [10].
• The effect of concurrent administration of phenobarbital on the hepatocarcinogenicity of N-nitrosodiethylamine (diethylnitrosamine; DENA) in rats was investigated by determination of the incidence of gamma-glutamyltransferase (gamma-glutamyltranspeptidase) (GGT)-positive foci and liver tumors [1].
• Changes in gamma-glutamyltransferase activity during N-2-fluorenylacetamide-induced rat hepatocarcinogenesis [11].

Chemical compound and disease context of Ggt1

• Ethanol effects in a rat hepatoma cell line: induction of gamma-glutamyltransferase [12].
• The clone C2 derived from a rat hepatoma cell line was used to investigate the mechanism of the induction of gamma-glutamyltransferase by ethanol. gamma-glutamyltransferase activity was detected in the C2 cell (1.4 mU per mg protein), and its kinetic properties were similar to normal rat liver gamma-glutamyltransferase [12].
• Parameters of liver injury and cholestasis were obtained by assaying the serum activities of isocitrate dehydrogenase and gamma-glutamyltransferase [13].
• ANIT treatment caused cholestasis and elevations in serum of total bilirubin concentration, total bile acid concentration, aspartate amino-transferase activity, gamma-glutamyltransferase activity and histologic lesions consistent with acute, neutrophilic cholangiohepatitis [14].
• Administration of acivicin, 36 mg/kg body weight, to glutamine-fed rats inhibited gamma glutamyltransferase > 90% and decreased kidney glutamate content 42% [15].

Biological context of Ggt1

• The expression of gamma-glutamyltransferase in rat colon carcinoma cells is distinctly regulated during differentiation and oxidative stress [16].
• Radiation-induced upregulation of gamma-glutamyltransferase in colon carcinoma cells is mediated through the Ras signal transduction pathway [17].
• These data suggest that expression of gamma-glutamyltransferase and glutathione transferase-P expression are part of a reorientation of cellular gene expression during carcinogenesis and that activated ras expression, like chemical carcinogens, can bring about this change [18].
• Leukotriene C4 is converted to the more potent leukotriene D4 by the action of gamma-glutamyltransferase on guinea pig ileum during bioassay. gamma-Glutamyltransferase may represent a control feature in the biosynthesis of leukotriene D4, and thus be involved in leukotriene-induced bronchoconstriction in the lung [19].
• We report evidence that the enzyme transglutaminase (glutaminyl-peptide gamma-glutamyltransferase; R-glutaminyl-peptide:amine gamma-glutamyltransferase, EC2.3.2.13) participates in receptor-mediated endocytosis [20].

Anatomical context of Ggt1

• Gamma glutamyltransferase (GGT) is a plasma membrane bound enzyme that initiates the degradation of glutathione [16].
• Among the presumptively preneoplastic hepatocytes, the gamma-glutamyltransferase (GGT)-positive cells were less sensitive to phalloidin than GGT-negative cells, indicating a greater contribution to the decrease in the sensitivity to phalloidin of the presumptively preneoplastic cells [21].
• Histologically, epithelial cell tumors showed a marked decrease in both gamma-glutamyltransferase activity and trypan blue uptake, but mesenchymal cell tumors did not [22].
• A model for the changes in gamma-glutamyltransferase during leukotriene release is proposed for the cell line, and differences from the guinea pig lung system are reported [19].
• The membrane-associated gamma-glutamyltransferase seems to be an integral membrane protein which cannot be washed away from the membranes [23].

Associations of Ggt1 with chemical compounds

• Changes in gamma-glutamyltransferase (GGT) activity throughout the course of rat hepatocarcinogenesis induced by brief dietary exposure to N-2-fluorenylacetamide (2-FAA) followed by promotion with dietary phenobarbital (PB) were studied [11].
• gamma-Glutamyltransferase and the inhibition of azo dye-produced neoplasia by concomitant administration of disulfiram [24].
• Simultaneous feeding of gliadin and swainsonine, an inhibitor of alpha-D-mannosidases, in rats disturbed enterocytic maturation as shown by a marked loss of activities of alkaline phosphatase and gamma-glutamyltransferase [25].
• Several observations argue in favor of an increase in the biosynthesis of gamma-glutamyltransferase after ethanol addition: (i) ethanol increased the maximal velocity of the enzyme and did not modify the affinity for its substrates [12].
• Animals given hydrocortisone showed a large decrease (71%) in the number of gamma-glutamyltransferase-positive foci [26].

Enzymatic interactions of Ggt1

• These conditions are also required for the maximal expression of the gamma-glutamyltransferase reaction catalyzed by glutamine synthetase [27].

Regulatory relationships of Ggt1

• Rat placental lactogen in the absence of prolactin and progesterone is able to induce gamma-glutamyltransferase activity [28].

Other interactions of Ggt1

• Five weeks after the DEN treatment, numbers and sizes of gamma-glutamyltransferase (GGT)- or GST-P-positive lesions and 8-hydroxyguanine (8-OHG) levels in the livers were significantly less in GST-P-Tg rats than in N-Tg rats [29].
• At these experimental times, the activities of glutathione peroxidase, glutathione reductase, glutathione-S-transferases and gamma-glutamyltransferase in the liver of lindane-treated rats and control animals were comparable [30].
• Effect of H1 and H2 receptor antagonists on the serum activity of gamma-glutamyltransferase during liver regeneration after partial hepatectomy in rats [31].
• Changes in the activities of rat hepatic glutathione (GSH) peroxidase (GSH-Px) and GSH reductase (GR) were investigated during the induction of preneoplastic gamma-glutamyltransferase (gamma-GT)-positive foci and hyperplastic nodules by the administration of diethylnitrosamine followed by N-2-fluorenylacetamide [32].
• Induction of gamma-glutamyltransferase-positive and nonspecific esterase-positive foci in rat liver by partial hepatectomy following single injection of N-nitrosodiethylamine [33].

Analytical, diagnostic and therapeutic context of Ggt1

• Immunocytochemistry with a specific antiserum and protein A-horseradish peroxidase permits visualization of the sites of gamma-glutamyltransferase [(5-glutamyl)-peptide:amino-acid 5-glutamyltransferase, EC 2.3.2.2] at both the light- and the electron-microscope levels [34].
• Control groups given individual carcinogen or partial hepatectomy alone or in dual combination were not suppressed in their immune function and failed to develop hyperplastic foci or changes in liver gamma-glutamyltransferase [35].
• Ovariectomy and ovariectomy plus hysterectomy on day 18 of pregnancy increased gamma-glutamyltransferase activity in the mammary gland [28].
• DESIGN: Laboratory in vivo study of the effects of sesame oil on serum aspartate aminotransferase, gamma-glutamyltransferase, alkaline phosphatase, total bilirubin, blood urea nitrogen, creatinine, lipid peroxide, and nitric oxide concentrations [36].
• The increase in total basolateral gamma-glutamyltransferase activity by T3 at early times after treatment was due mainly to increments in its transpeptidation mechanism, and was characterized by increments in the apparent maximum velocities without changes in the apparent Michaelis constant (Km) for the substrate gamma-glutamyl-p-nitroanilide [37].

References