• Toxicological Research
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• 제14권2호
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• pp.177-181
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• 1998

Dithiocarbamate and mixed disulfide containing allyl functions were designed and synthesized as putative chemopreventive agents, i.e. N,N-diallyldithiocarbamate (DATC) and S-(N,N-diallyldithiocarbamoyl)-N-acetylcysteine (AC-DATC). DATC and AC-DATC were administered and the activities of cytosolic glutathione S-transferase (GST), glutathione reductase (GR) and microsomal N-nitrosodiethylamine (NDEA) deethylase were assayed in order to test the effects of these organosulfur com-pounds on the detoxification and metabolic activation system of NDEA. The amounts of hepatic glutathione (GSH and GSSG) was also determined. The administration of DATC to rats led to an increase in the activity of GR and to an inhibition of CYP2E1-mediated NDEA deethylation. AC-DATC induced the activity of GR and GST, increased the hepatic GSH content and inhibited the rate of NDEA deethylation. The level of GSSG was decreased as a consequence of the increased activity of GR. These effects may contribute to possible antimutagenic and anticarcinogenic action of the dithiocarbamates investigated.

• 환경생물
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• 제21권3호
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• pp.297-302
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• 2003

This study was designed to determine whether selenium (Se) nutrition affects pulmonary glutathione peroxidase and alveolarization in the neonatal rat. Twenty-four female Sprague Dawley rats were bred and fed a semipurified Se-deficient (0.04 ppm, Se-) or a Se-adequate (0.5 ppm, Se+) diet through pregnancy and lactation. Pulmonary DNA synthesis was slightly higher in Se+ pups than in Se- pups on d 6 and d 9 of lactation, but significant difference was not found. As pulmonary alveolarization progressed, mean air space size decreased and internal surface area and lung volume increased. No difference in pulmonary alveolarization was found between Se- and Se+ pups by age. Pulmonary Se concentration was higher in Se+ pups than in Se- pups at all age. Glutathione peroxidase activity in lung tissur reflected Se status and was lower in Se- pups than in Se+ pups. In conclusion, selenium has no significant effect on alveolarization of neonatal lungs. but it is necessary for adequate supply of pulmonary antioxidant, glutathione peroxidase.

• Journal of Microbiology and Biotechnology
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• 제1권3호
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• pp.157-162
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• 1991

Conditions for glutathione production in E. coli cells which possess pGH501 (2 gshI+gshII) were studied. In terms of ATP supply for the glutathione synthesis, two different systems have been constructed and compared. When the acetate kinase reaction of E. coli was used for ATP generation, 20 mM of L-cysteine was completely converted to glutathione by toluene-treated E. coli cells (100 mg/ml) harboring pGH501 within 2 h at $37^{\circ}C$. However, considering the economical aspects, the glycolytic pathway of yeast was chosen as a better system for ATP generation. The optimal concentrations of reactants for glutathione production were determined to be as follows; 80 mM L-glutamate, 20 mM L-cysteine, 20 mM glycine, 20 mM $MgCl_2$, 50 mM potassium phosphate buffer (pH 7.5), 400 mM glucose, polyoxyethylene stearylamine ($5\;\mul/ml$), toluene-treated E. coli HB101/pGH501 (100 mg/ml), and dried yeast cells (400 mg/ml). The conversion ratio of L-cysteine to glutathione was 80% (about 5 mg/ml) under optimal condition within 6 h at $37^{\circ}C$.

• Journal of Preventive Medicine and Public Health
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• 제35권4호
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• pp.269-274
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• 2002

Balb/c 마우스의 복강내에 Abelson leukemia virus (A-MuLV)를 주입하여 발생시킨 대식세포주 RAW 264.7 세포의 배양조건에 납과 NAC및 BSO를 첨가하여 세포생존율과 NO 및 ATP 생성량의 변화를 관찰한 결과, 납을 처리한 기본배양조건에서 RAW 264.7 세포의 생존율은 각 농도에서 차이가 없었으며 NO의 생성량은 $0.5{\mu}M$의 납농도에서부터 용량 의존적으로 감소하였으나 ATP의 생성량은 각 농도군에서 차이가 없었다. NAC을 전처리하고 납을 처리한 배양조건에서의 NO 및 ATP의 생성량은 대조군과 차이가 없었다. BSO를 전처리하고 납을 처리한 배양조건에서의 NO의 생성량은 납만 처리했을 때와 달리 각각의 농도군에서 대조군과 차이가 있었다. ATP생성량은 역시 차이가 없었다. 이상의 결과에서 납의 농도가 증가함에 따라 ATP의 생성량은 변화가 없으면서 NO가 감소하는 것을 볼 때, 납에 의한 대식세포에서 NO생성의 억제기전은 수은 및 카드뮴 등과 같이 미토콘드리아에 영향을 미쳐 ATP생성이 억제됨으로 L-arginine-NO경로에서 ATP를 필요로 하는 iNOS가 작용을 못하여 NO 생성이 저하되는 기전과는 다른 기전이 있음을 보여준다. 또한 iNOS의 조효소인 세포내 GSH를 증가시키는 NAC을 전처리했을 때 NO의 생성량이 대조군 수준으로 회복되고 세포내 GSH를 감소시키는 BSO를 전처리했을 때는 오히려 NO의 생성량에 영향을 미치지 않는 납의 농도에서조차 NO 생성의 감소가 일어난 것으로 볼 때 GSH는 대식세포에서 NO생성을 저하시키는 납의 독성에 보호작용이 있음을 확인할 수 있었다.

• 한국초지조사료학회지
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• 제43권2호
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• pp.109-115
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• 2023

Ammonium (NH₄⁺) serves as a nitrogen source, but its elevated levels can hinder plant growth and production. Excess NH₄⁺ with α-ketoglutarate is assimilated into glutamate, a precursor of proline and glutathione (GSH). This study aimed to investigate the effects of excessive NH₄⁺ on the regulation of proline and GSH synthesis. Detached leaves from oilseed rape (Brassica napus L.) were fed with 0, 50, 100, 500, and 1000 mM NH₄Cl for 16 h. As the NH₄⁺ concentrations increased, the leaves exhibited progressive wilting and yellowing. Furthermore, total carotenoid and chlorophyll concentrations declined in response to all NH₄⁺ treatments, with the lowest levels observed in 1000 mM NH₄⁺ treatment. Hydrogen peroxide (H₂O₂) concentration showed a minor increase at low NH₄⁺ concentration (50 and 100 mM) treatments but a significant increase at high NH₄⁺ (500 and 1000 mM), which was consistent with the localization of H₂O₂. Amino acid concentrations increased with increasing in NH₄⁺ concentration, while the protein concentration displayed the opposite trend. Proline and cysteine concentrations exhibited a gradual increase in response to increasing NH₄⁺ concentrations. However, GSH concentrations rose only in the 50 mM NH₄⁺ treatment and decreased in the 500 and 1000 mM NH₄⁺ treatments. These results indicate that excessive NH₄⁺ is primarily assimilated into proline, while GSH synthesis is adversely affected.

• Preventive Nutrition and Food Science
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• 제16권4호
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• pp.313-320
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• 2011

The oxidative stress level and antioxidant activities in two green algae (Ulva pertusa and Ulva linza), two brown algae (Agarum cribrosum and Dictyota dichotoma), and three red algae (Grateloupia lanceolata, Carpopeltis affinis, and Gracilaria verrucosa) collected from intertidal regions of Korea were assessed. In the two green algae, although the total glutathione content was not as high as that of the brown algae, the glutathione pool was extremely reduced, and the glutathione reductase (GRd)/glutathione peroxidase (GPx) activity ratio was high, which apparently plays an important role for protection against oxidative damage, as manifested by low lipid peroxidation. In the brown algae, which exhibited a low lipid peroxidation level that was comparable to the green algal species, the highest glutathione content, together with high GPx activity, appears to be the most important factor in their antioxidant protection. The red algal species exhibited extremely high lipid peroxidation levels. They also contained the lowest and most oxidized glutathione among the species, as well as the lowest GRd activity. In spite of the marked difference in the glutathione content, the significant difference in the activity of ${\gamma}$-glutamylcysteine ligase, the rate limiting enzyme for glutathione synthesis, among the species was not exhibited. Our results suggest that there is a significant difference in the levels of oxidative stress and antioxidant capacity among the algal species, and that the glutathione system, especially the efficiency of glutathione recycling, plays a vital role in antioxidative protection in algal species.

• The Korean Journal of Physiology and Pharmacology
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• 제2권4호
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• pp.511-519
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• 1998

This study investigated the role of nitric oxide on the oxidative damage in gastric mucosa of rats which received ischemia/reperfusion and its relation to mucus. Nitric oxide synthesis modulators such as L-arginine and $N^G-nitro-L-arginine$ methyl ester, and sodium nitroprusside, a nitric oxide donor, were injected intraperitoneally to the rats 30 min prior to ischemia/reperfusion which was induced by clamping the celiac artery and the superior mesenteric artery for 30 min and reperfusion for 1 h. Lipid peroxide production, the contents of glutathione and mucus, and glutathione peroxidase activities of gastric mucosa were determined. Histological observation of gastric mucosa was performed by using hematoxylin-eosin staining and scanning electron microscopy. The result showed that ischemia/reperfusion increased lipid peroxide production and decreased the contents of glutathione and mucus as well as glutathione peroxidase activities of gastric mucosa. Ischemia/reperfusion induced gastric erosion and gross epithelial disruption of gastric mucosa. Pretreatment of L-arginine, a substrate for nitric oxide synthase, and sodium nitroprusside prevented ischemia/reperfusion-induced alterations of gastric mucosa. However, $N^G-nitro-$ L- arginine methyl ester, a nitric oxide synthase inhibitor, deteriorated oxidative damage induced by ischemia/reperfusion. In conclusion, nitric oxide has an antioxidant defensive role on gastric mucosa by maintaining mucus, glutathione, and glutathione peroxidase of gastric mucosa.

• Journal of Nutrition and Health
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• 제26권3호
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• pp.286-298
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• 1993

In order to investigate the effect of selenium (Se) on the liver damage, metallothionein synthesis and hepatic antioxidative detoxification system in cadmium(Cd) administered rats. Sprague-Dawley male rats(60\\5g) were divided into two diet groups, depending on with (CdS groups) or without (Cd groups) 0.5ppm Se supplementation and fed experimental diets ad libidum for 4 weeks. And then each group was again subdivided into five groups, depending on injection number of Cd, i.e., 0, 1, 2, 3, and 4 times of 2.5mg Cd/kg of body wt once a day. Hemoglobin concentration, hematocrit values, superoxide dismutase, glutathione peroxidase and glutathione S-transferase activite were decreased progressively with increasing number of Cd injection, but increased by the supplementation of Se. The reduced form of glutathione (GSH) contents in blood and liver and vitamin E content were decreased and oxidized form (GSSG) increased in Cd groups, but these of Se supplemented groups were not very different from controls. Cd reduced liver vitamin E content which was not restored by Se supplementation. Liver lipid peroxide values were elevated with increasing doses of Cd, but Se supplementation reduced these elevated levels. Accumulation of metallothionein in liver and kidney was increased with increasing number of Cd injection, but Se did not affect on them. Histological examination revealed that lysosomes were significantly increased and mitochondria and Golgi apparatus were enlarged by Cd, however, these changes were reduced by Se. It was concluded that Se administration promoted antioxidative detoxification and alleviated peroxidative damage in rat liver by Cd.

• 약학회지
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• 제53권6호
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• pp.314-320
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• 2009

We examined metabolic conversion of cysteine into glutathione (GSH) and taurine in rat liver under oxidative stress. Administration of tert-butylhydroperoxide (t-BHP) into the portal vein of male rats resulted in a rapid elevation of serum sorbitol dehydrogenase, alanine aminotransferase, and aspartate aminotransferase activities, which decreased gradually in 24 hr. Hepatic cysteine concentration was reduced in 3 hr, and recovered progressively, reaching a level greater than 200% of the normal value in 24 hr. GSH was increased both in liver and blood at 9 hr after t-BHP challenge, whereas hypotaurine or taurine was not altered. $\gamma$-Glutamylcysteine synthetase (GCS) activity was increased from 9 hr after t-BHP treatment, but protein expression of the GCS-heavy subunit was not changed in liver. Activity or expression of cysteine dioxygenase was not affected by t-BHP treatment. Taken together, these data show that an acute oxidant challenge to the rats may induce upregulation of cysteine availability and GCS activity, resulting in an enhancement of hepatic GSH synthesis, but the increased cysteine level does not stimulate taurine synthesis via cysteine sulfinate pathway. It is indicated that the regulation of GSH and taurine biosynthesis from cysteine is not solely dependent on the cysteine concentration in rat liver under oxidative stress.

• Toxicological Research
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• 제14권2호
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• pp.157-161
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• 1998

The mechanism of active aldehyde-induced liver disease and the enzymatic basis of detoxification were investigated using normal rat liver cell, Ac2F. Aliphatic alcohols including l-decyl alcohol, l-nonanol, l-heptanol, l-hexanol, l-propanol and allyl alcohol exerted a dose- and time-de-pendent toxicity to Ac2F cells. The extent of their toxicities in buthionine sulfoximine (inhibitor of glutathione synthesis) pretreated cells was greater than in pargyline (inhibitor of aldehyde dehydrogenase, ALDH). On the other hand, the toxicity of these alcohols were not affected by 4-methylpyrazole (inhibitor of alcohol dehydrogenase, ADH). These results suggest that the contents of glutathione (GSH) seems to be very important in protecting the cells from toxicants such as aliphatic alcohols.