• The Korean Journal of Pesticide Science
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• v.2 no.3
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• pp.85-89
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• 1998

Effect of soil residue paraquat (1,1-dimethyl-4,4-dipyridinium dichloride) on growth of barley (Hordeum vulgare L. cv. Sacheon No.6 and cv. Tapgolbori) and soybean [Glycine max (L.) Merr. cv. Alcheon and Danyeop] was investigated. Changes in soil residue paraquat during the cultivation period and residue amount in the p1ants at harvest were also determined. Experiments were conducted at two paraquat residue conditions; the first was done in an apple orchard soil where paraquat residue recorded 30.2 ppm in 1996, but decreased to about 9 to 9.8 ppm at the time of crop seeding and the second was conducted in the soil fortified to about 27 to 32 ppm paraquat residue. In both conditions, no crop injury due to the residue paraquat was observed and number of emerged seedlings and plant height of the two crops were not affected by soil residue paraquat. Residue amount of paraquat in the plants occurred less than 0.5 ppm detection limit. At the first condition, soil residue paraquat was further slightly decreased for 90 days after seeding, while no great change in the residue level was found at the second condition for 30 days after seeding. The results suggest that no carry-over effect occurs at about 30 ppm of soil residue paraquat and at present crop cultivation in Korean orchard soils are safe with respect to crop growth and paraquat residue in the plants.

• Korean Journal of Weed Science
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• v.6 no.2
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• pp.191-200
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• 1986

The study was conducted to screen paraquat-tolerant plant species among crops and weeds, using the response of plant like leaf disc discoloration, visual injury and dry weight in the presence of paraquat. Mechanism of paraquat-tolerance was investigated in strains of soybean through evaluating activities of superoxide dismutase and peroxidase and the multiplication of callus derived from soybean cotyledon. In crops, Kwanggyo has been selected as a paraquat-tolerant variety among soybean cultivars tested, and Hood as a susceptible one. In weeds, Polygonum aviculare, Chenopodium album and Pinellia ternata were evaluated as the paraquat resistant species, providing the possibility for the donor plant species for paraquat resistance. Activity of superoxide dismutase known to detoxify paraquat was markedly greater in Kwanggyo, a paraquat-tolerant cultivar than in Hood, a susceptible one. In addition, the similar response like superoxide dismutase was observed in peroxidese activity. The greater inhibition of callus multiplication was determined in Hood, a susceptible one than a tolerant one, Kwnggyo. Based on all the informations, it is strongly proposed that paraquat tolerance in soybean is due to destruction of $O_2^-$ by elevated concentration of superoxide dismutase in the tolerant cultivar.

• The Korean Journal of Pesticide Science
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• v.2 no.1
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• pp.70-78
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• 1998

This study was conducted to investigate the adsorption-desorption characteristics of herbicide paraquat on clay minerals, humic materials, and soils under the laboratory conditions. Adsorption time of paraquat on clay minerals was faster than organic materials and soils. Adsorption amount on montmorillonite, 2:1 expanding-lattice clay mineral, was largest among the adsorbents tested. The adsorption capacity of paraquat was approximately 21 % of cation exchange capacity in soils, 45.1 % in kaolinite, and 80.6% in montmorillonite. Humic materials, humic acid and fulvic acid isolated from soil II, adsorbed larger amount of paraquat than kaolinite and soils. Distribution of tightly bound type of paraquat was larger in clay mineral and soils but loosely bound type was larger in humic acid and fulvic acid. In oxidized soil, the adsorption amount of paraquat was decreased to 85.1-95.5% of original soils. Distribution of unbound and loosely bound type of paraquat was decreased in oxidized soil but tightly bound type was increased. The competition cations decreased paraquat adsorption on humic materials and soils but not affected on montmorillonite. No difference was observed as the kinds of cations. In cation-saturated adsorbents, the adsorption amount was decreased largely in humic materials and soils but decreased a little in montmorillonite. The tightly bound type of paraquat in all adsorbents was not desorbed by pH variation, sonication, and cation application but loosely bound type was desorbed. However, the desorption amount was different as a kinds of adsorbents and desorption methods.

• Journal of Food Hygiene and Safety
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• v.1 no.2
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• pp.143-149
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• 1986

Paraquat의 만성독성에 대한 vitamin E 급여의 효과를 조사하기 위하여 랫드에 paraquat를 50 ppm의 농도로 희석한 물을 음수 대신 투여하면서 vitamin E 함유 사료를 급여하여 paraquat에 대한 vitamin E의 방어 효과를 측정하였는 바 다음과 같은 결과를 얻었다. 1.혈장 vitamin E 농도는 사료 kg 당 10 mg까지의 vitamin E 함유 사료의 급여로 약 150$\mu\textrm{g}$/100ml까지 급격히 상승하였으며 그 후 급여량의 증가에도 비교적 안정된 혈중 농도를 유지하였고, 또한 paraquat 투여는 vitamin E 급여량에 관계없이 혈중 vitamin E 농도의 감소를 가져왔다. 2. 간저장 vitamin E 농도는 혈장 vitamin E 농도와 달리 급여량의 증가에 따라 비례하여 증가하는 경향을 보였으며 paraquat 투여에 의한 영향이 적었다. 3. Paraquat 투여는 적혈구 용혈율을 크게 증가시켰음 (95%), 100$\mu\textrm{g}$/100ml 이상의 vitamin E 혈장 농도에서는 안정된 적혈구 용혈율 (10% 이하)을 나타내었다. 4. Paraquat 투여는 혈장 trypsin inhibitor capacity를 크게 증가시켰으며, vitamin E 급여에 의하여 다소 회복되는 경향을 보였으나 정상에 이르지 못하였다. 5. 혈장 및 적혈구 glutathione peroxidase 활성은 paraquat 투여에 의하여 영향을 받지 않았다. 6. paraquat 투여 후의 lipid peroxide는 vitamin E의 급여로 감소되었다.

• Toxicological Research
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• v.9 no.1
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• pp.23-33
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• 1993

In the present study, the effects of allopurinol on paraquat toxicity were investigated in paraquat-treated rats. The surivals of paraquat-treated rats were increased by allopurinol treatment. The contents of glutathione in liver and kidney were significantly decreased by paraquat, but restored by allopurinol. The activity of xanthine oxidase was significantly reduced but NADH dehydrogenase was not changed by allopurinol teatment. The activities of catalase, SOD and glutathione peroxidase in liver were significantly decreased by paraquat but catalase was restored by allopurinol treatment.

• Microbiology and Biotechnology Letters
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• v.28 no.1
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• pp.1-7
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• 2000

The bacterial strain JW-2 which conferred resistance against paraquat (1,1'-dimethyl-4,4'-bipyridinium dichloride) was isolated from soil. The strain was identified as an Ochrobactrum anthropi based on its morphological, physiological, biological and fatty acid composition, and was designated as Ochrobactrum anthropi JW-2. We compard paraquat resistance of O. anthropi JW-2 with Escherichia coli J105. In the presence of 100mM paraquat, E. coli JM105 was not grown whereas the growth rate of O. anthropi was about 70% of control. We compared the sensitivity of O. anthropi JW-2 and E. coli J105 to redox-cycling compounds such as paraquat, plumbagin or menadione, which are known to exacebate wuperoxide generation. O. anthropi JW-2 did not show cross-resistance to plumbagin or menadione. superoxide dismutase activity was increased in paraqunt-treated E. coli JM105 while it was not increased in O.anthropi JW-2. These results suggest that the mechanism of paraquat resistance in O.anthropi JW-2 is probably due to selectively decreased permeability toward paraquat by membrane protein.

• Environmental Analysis Health and Toxicology
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• v.13 no.3_4
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• pp.117-123
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• 1998

Paraquat is a useful nonselective herbicide widely used throughout the world. However, accidental or intentional ingestion of the paraquat cause fetal pulmonary injuring. But there is not suitable antidote of paraquat intoxication and therapeutic agents now be used are not effective. So, in this study we intended to evaluate the inhibitory effects of DDB(dimethyl-4,4'dimethoxy-5,6,5',6'-dimethylene dioxyphenyl-2,2'-dicarboxylate) on paraquat toxicity. DDB (100mg/kg) was administered orally to SD rats lhr after paraquat(50mg/kg) injection. After 24 hours, the biochemical parameters of blood and tissues were examined. In paraquat treated groups sGPT, sGOT, BUN, creatinine, MDA and alkaline phosphatase levels in blood and MDA, glucose-6-phosphatase activity in tissues were elevated by 2 to 5 times of normal values. However in schizandrin treated groups, sGPT, sGOT, MDA and alkaline phosphatase activity in blood and MDA and glucose-6-phosphatase activity were significantly decreased to notmal levels but not in biochemical parameters of nephrotoxicity, BUN and creatinine levels. Therefore, we concluded that schizandrin can be used as an antidote of pulmono, hepatotoxicity of paraquat.

• YAKHAK HOEJI
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• v.32 no.5
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• pp.351-361
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• 1988

The herbicide, paraquat, has caused numerous poisonings in man and farm animals since its interoduction. Althought the lungs are the primary sites of toxicological effect, other organs are also damaged, such as liver, heart, and kidney. The biochemical mechanisms responsible for the toxicity of the herbicide are not clearly understood. The purpose of the present study was to determine the hepatotoxity of paraquat in rats and the effects of glycyrrhizin on the paraquat toxicity. The experimental results are the followings. 1. The values of serum AST, ALT, LDH, ALP, glucose, and cholesterol were significantly increased in the paraquat administered group. 2. The TBA values in serum and liver were also increased in the treated group. 3. The biochemical parameters of serum, such as AST, ALT, LDH and TBA values, were significantly low in the paraquat plus glycyrrhizin group in comparison with that of the paraquat only. The above results suggest that the glycyrrhizin, somehow, detoxify the hepa to toxicity of paraquat in the experimenta-animals.

• Journal of The Korean Society of Clinical Toxicology
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• v.2 no.2
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• pp.101-105
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• 2004

Purpose: Paraquat is the most commonly used herbicide in Korea. Exposure to paraquat through the skin has resulted in local irritation or inflammation of varying degree, sometimes severe. The purpose of this study was to review the patients with paraquat poisoning by skin absorption. Methods: We analysed retrospectively the clinical and laboratory findings of 45 patients with paraquat poisoning after dermal exposure, who were admitted to Soonchunhyang University Cheonan Hospital from January 1999 to December 2003. Results: Among 870 cases of paraquat poisoning, 45 cases were exposed to paraquat through the skin. The peak incidence was the fifth decade($40\%$). The clinical symptoms were pain, pruritus, nausea, and vomiting. The major skin lesions were generalized vesicobullae and necrotic erosion in face, scrotum, trunk, upper and lower extremities and etc. All patients were survived after skin contact or inhalation of paraquat. Conclusion: This study illustrates the extreme toxicity of paraquat and demonstrates that lethal quantities of paraquat may be absorbed if repeated exposure to it. Stricter precautions, including the mandatory use of protective clothing, should be recommended whenever this material is used.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.1 no.2
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• pp.87-91
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• 1997

Leaf discs were excised from spinach leaves (Spinacia oleracea L.) and floated in phosphate buffer (pH 6.8) containing paraquat solutions (0, 0.1, 1.0, 10, 20, 50 and 100 ppm), and incubated in the growth chamber under 5,500 lux illumination at $25^{\circ}C$ for 24 hr. Treatment with paraquat caused the formation of malondialdehyde (MDA), an indicator of lipid peroxidation in leaf discs. When 1.0, 10, 20, 50 and 100 ppm of paraquat solutions were applied to leaf discs, the contents of MDA were increased by 63, 86, 100, 140 and $150\%$ of the level without paraquat treatment respectively. 1.0, 10, 20, 50 and 100 ppm of paraquat treatments reduced the amounts of ascorbic acid in leaf discs by 23, 35, 38, 42 and $56\%$ of the level without paraquat treatment, respectively. Activities of superoxide dismutase (SOD) in leaf discs of 1.0, 10, 20, 50 and 100 ppm of paraquat treatments were decreased by 23, 42, 48, 61 and $70\%$ of the level of SOD in non-treated group, respectively. The results suggest that paraquat may cause peroxidation of membrane lipid in spinach leaves as a result of paraquat-induced destruction of physiological defense against oxygen phytotoxicity.