• Journal of Life Science
• /
• v.7 no.4
• /
• pp.253-261
• /
• 1997

In order to enhance glutathione production, various recombinant plasmids containing gshI and/or gshII genes isolated from E. coli K-12 were constructed and introduced into E. coli. Some plasmids contained one to three copies of gshI genes in pBR325 and others contained both gshI and genes for glutathione biosynthesis. $\gamma$-Glutamylcysteine synthetase activities of E, coli strains amplified tandem repeated gshI genes were dependent on the number of inserted gshI genes. The glutathione productivity of E. coli strains harboring various plasmids was investigated using an E. coli acetate kinase reaction as an ATP regenerating system. The glutathione productivity of E. coli strains harboring tandem repeated gshI genes was increased in proportion to the number of inserted gshI genes. By the introduction of gshII gene, the glutathione productivity of the E. coli was increased by two-fold compared with E. coli strain amplified gshI gene only. The enzymatic production of glytathione in E. coli was mainly affected by the increase of $\gamma$-glutamylcysteine synthetase activity. The highest glutathione productivity was obtained in E. coli strains harboring pGH-501 plasmid containing two copies of gshI and copy of gshII genes in pUC8 vector.

• YAKHAK HOEJI
• /
• v.35 no.5
• /
• pp.384-388
• /
• 1991

To explore the effect of monosodium-L-glutamate(MSG) on CCI$_{4}$-damaged liver in Wister male rat, 5% MSG solution as drink water were administered after S.C. injection of 0.1 mg/kg CC1$_{4}$ twice a week for 4 weeks. After last administration of MSG, heptic glutathione(GSH) dependent system was assayed. It showed that MSG increased significanly hepatic glutathione(GSH) and glutathione peroxidase(GSH$_{px}$), but decreased glutathione-S-transferase(GST) acivity in normal rats. MSG increased significantly the GSH$_{px}$ and GST activities in rats with CCI$_{4}$-induced liver damage. These results indicate that decrease of GSH dependent systems in CC1$_{4}$ liver injury might be partially elevated by coadministration of MSG.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.20 no.4
• /
• pp.285-292
• /
• 1991

The effects of acute and chronic ethanol administration on hepatic and cerebellar glutathione (GSH) statuses and lipid peroxide levels in rats were investigated. In the liver, chronic ethanol feeding (6.9 g/kg, per day) as 10% (v/v) drinking water for 4 weeks produced a slight decrease of total GSH and an increase in the ratio of GSSG/total GSH without change of GSSG (oxidized GSH). Lipid peroxide level however was not modified. Many other studies have shown the acute ethanol loading effect in the rat liver, that is moderate decrease of total GSH and elevation of lipid peroxide level. Relating to this, it was observed that total GSH in the plasma obtained from post. hepatic inferior vena cava was increased by acute ethanol injection (50 mmol/kg, i.p.). This increased hepatic efflux of GSH into blood, in addition to the promoted antioxidative utilization of GSH, could be suggested as one of the possible reasons for the decrease of hepatic GSH induced by ethanol load. In the cerebellum, acute ethanol load did not change the total GSH and GSSG, but increased the lipid peroxidation rate. In the chronic, neither GSH pattern nor lipid peroxidation rate was changed.

• Environmental Analysis Health and Toxicology
• /
• v.22 no.3
• /
• pp.227-233
• /
• 2007

It has been reported that hepatic glutathione (GSH) levels are decreased in diabetic patients, and glucagon increases hepatic efflux of GSH into blood. The signaling pathways responsible for mediating the glucagon effects on GSH efflux, however, are unknown. The signaling pathways involved in the regulation of GSH efflux in response to glucagon and insulin were examined in primary cultured rat hepatocytes. The GSH concentrations in the culture medium were markedly increased by the addition of glucagon, although cellular GSH levels are significantly decreased by glucagon. Insulin was also increased the GSH concentrations in the culture medium, but which is reflected in elevations of both cellular GSH and protein. Treatment of cells with 8-bromo-cAMP or dibutyryl-cAMP also resulted in elevation of the GSH concentrations in the culture medium. Pretreatment with H89, a selective inhibitor of protein kinase A, before glucagon addition markedly attenuated the glucagon effect. These results suggest that glucagon changes GSH homeostasis via elevation of GSH efflux, which may be responsible for decrease in hepatic GSH levels observed in diabetic condition. Furthermore, the present study implicates cAMP and protein kinase A in mediating the effect of glucagon on GSH efflux in primary cultured rat hepatocytes.

• The Korean Journal of Physiology and Pharmacology
• /
• v.1 no.2
• /
• pp.221-224
• /
• 1997

Effects of melatonin on hepatic glutathione-peroxidase (GSH-Px) and glutathione-reductase (GSH-reductase) activities were studied in Sprague-Dawley (SD) rats administered i.p. (10 mg/kg body weight) with melatonin during 15 days. The activity of cytosolic GSH-reductase in the liver was not changed by melatonin. However, melatonin injection increased significantly the activity of liver cytosolic GSH-Px activity compared with those in saline-treated rats. At the same time, plasma GSH-Px was also increased significantly in melatonin-treated rats. Since GSH-Px, a major antioxidative enzyme, removes $H_2O_2$ and lipid peroxides which are formed during lipid peroxidation from cellular membrane, such elevation of heptatic GSH-Px activity may contribute to the improvement of antioxidative effects under oxidative damage in the liver.

• Toxicological Research
• /
• v.9 no.2
• /
• pp.159-166
• /
• 1993

The treatmene of V79 cells with diethyl maleate (DEM) led to decrease in glutathione (GSH) level as increasing DEM concentration. Mercuric chloride, treated for 6 hrs with 2ng/ml, affected the GSH metabolizing enzymes glutathione S-transferase (GST) and glutathione peroxidase (GSP), dropping their activities to 60% and 75%, respectively, though not so much in GSH level(80%). However, the toxic effects of mercuric chloride on those enzymes and GSH level were both amplified when the Hg2+ treatment was combined with the preceding DEM treatment.

• Bulletin of the Korean Chemical Society
• /
• v.35 no.10
• /
• pp.3047-3051
• /
• 2014

In this paper, we describe a new method for the selective extraction and quantification of glutathione (GSH) using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and maleimide-presenting gold nanoparticles (Mal-AuNPs). Our strategy utilizes the Michael addition to selectively extract GSH, from chosen samples, onto the maleimide of Mal-AuNPs. After the extraction step, the GSH bound to the AuNPs was analyzed by MALDI-TOF MS in the presence of an internal standard which was prepared by reacting Mal-AuNPs with isotope-labeled GSH ($GSH^*$). The $GSH^*$ has the same structure as GSH but a higher molecular weight, and therefore, enables absolute quantification of GSH by comparing the mass signal intensities of the GSH- and $GSH^*$-conjugated alkanethiols. Our strategy was verified by analyzing GSH-spiked fetal bovine serum and NIH 3T3 cells.

• Journal of Microbiology
• /
• v.41 no.3
• /
• pp.248-251
• /
• 2003

Glutathione (GSH) is an important factor in determining tolerance against oxidative stress in living organisms. It is synthesized in two sequential reactions catalyzed by ${\gamma}$-glutamylcysteine synthetase (GCS) and glutathione synthetase (GS) in the presence of ATP. In this work, the effects of three different oxidative stresses were examined on GSH content and GSH-related enzyme activities in the fission yeast Schizosaccharomyces pombe. GSH content in S. pombe was significantly enhanced by treatment with hydrogen peroxide, ${\beta}$-naphthoflavone (BNF) and tert-butylhydroquinone (BHQ). Simultaneously, they greatly induced GCS and GS activity. However, they did not have any effects on glutathione reductase activity. These results suggest that GCS and GS activities in S. pombe are up-regulated by oxidative stress.

• Korean Journal of Environmental Biology
• /
• v.29 no.4
• /
• pp.258-264
• /
• 2011

Glutathione (GSH) has important roles in cellular defense against oxidative stress, 1) direct scavenging of reactive oxygen species (ROS), and 2) coenzyme of ROS scavenging enzyme like glutathione peroxidases (GPx). GSH peroxidase reduces free hydrogen peroxide to water using 2GSH. $N$-acetyl-L-cysteine (NAC), one of the antioxidants, is used as a precursor for intracellular GSH. In this study, relation of GSH, NAC, and GSH peroxidase was investigated through transcriptional expression of $GPX1$ and $GPX2$, which are GSH peroxidase encoding genes, in yeast cells treated with 0 mM to 20 mM of NAC or in combination with 100 Gy gamma-rays. The transcriptional expression of $GPX1$ and $GPX2$ was induced by NAC and 100 Gy gamma-rays. The gene expression of both GSH peroxidases was decreased with increasing concentrations of NAC in irradiated yeast cells. These results suggest that elevation of intracellular GSH by NAC and oxidative stress and ROS generated from gamma-rays induces expression of GSH peroxidase genes, and that NAC can protect the yeast cells against ROS generated from gamma-rays through direct scavenging of ROS and transcriptional activation of GSH peroxidase.

• Korean Journal of Plant Tissue Culture
• /
• v.27 no.1
• /
• pp.57-61
• /
• 2000

We investigated the levels of glutathione (GSH) and its oxidized form (GSSG) in 24 cell lines derived from various plant species to understand the antioxidative mechanism in plant cell cultures. The total glutathione content was 98$\pm$27 $\mu$g/g cell fresh wt, showing a slight difference in plant species. The average contort of GSH and GSSG was 72$\pm$20 and 26$\pm$10 $\mu$g/g cell fresh wt, respectively. The average GSH content in plant cell lines occupies approximately 73% in total glutathione. During the suspension cultures of Scutellaria baicalensis, one of the plant species we tested, the GSH content decreased in proportion to the cell growth during the exponential growth stage, showing the low level at the stationary growth stage (84 $\mu$g/g cell fresh wt), whereas the GSSG content increased to the stationary growth stage (31 $\mu$g/g cell fresh wt). The results suggested that the ratio of GSH and GSSG should be involved in the cell growth and antioxidative mechanism in cultured cells.