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ABSTRACT: In recent years, commercial glyphosate herbicide formulations have been widely used in agriculture to control aquatic weeds. These pesticides may result in disruption of ecological balance, causing damage to nontarget organisms including fish. Teleostean fish (Leporinus obtusidens) were exposed to commercial glyphosate herbicide formulation at 0 (control), 3, 6, 10 or 20 mg L(-1) for 96 h. The effects of herbicide on plasmatic metabolic parameters, thiobarbituric acid reactive substances (TBARS), catalase activity, protein carbonyl, and mucus layer parameters were studied. Plasmatic glucose and lactate levels increased but protein levels showed reduction after herbicide exposure. TBARS levels in brain showed a reduction at all tested concentrations. However, liver demonstrated increased TBARS levels at all tested concentrations, whereas in white muscle TBARS production did not change after exposure to herbicide. Fish exposed to all concentrations of glyphosate showed increase in liver catalase activity and protein carbonyl. Herbicide exposure increased protein and carbohydrate levels of the mucus layer at all tested concentrations. The present results showed that, in 96 h, glyphosate changed toxicological parameters analyzed in piava. Parameters measured in this study may be useful in environmental biomonitoring.
Archives of Environmental Contamination and Toxicology 04/2011; 61(4):624-30. · 1.93 Impact Factor
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ABSTRACT: This study aims to verify the effects of the clomazone concentration used in rice fields on acetylcholinesterase (AChE), thiobarbituric acid reactive substances (TBARS), protein carbonyl and catalase activity in tissues of piava (Leporinus obtusidens). LC(50)-96h was 5.0 mg L(-1) and the fish were exposed to 1/10 of LC(50)-96 h: 0.5 mg L(-1) of clomazone for 96 and 192h. The same parameters were also assayed after a recovery period of 192 h in clean water. AChE activity was reduced only in the brain and heart of fish exposed for 96 h. AChE activity was decreased in the brain, muscle and heart tissues after 192 h of exposure. After 192 h of recovery period, AChE activity remained diminished in brain and muscle and showed a decrease in eye. However, after 192 h of recovery, AChE activity in heart was recovered. Fish showed increased TBARS levels in brain at all experimental periods. TBARS levels decreased in liver and muscle tissues after 192 h of exposure. The increase in muscle TBARS persisted in fish transferred to clean water. Protein carbonyl in the liver was increased in all periods studied including the recovery period. Catalase activity was reduced during all periods. The present study demonstrates the occurrence of disorders in AChE, TBARS, protein carbonyl and catalase activity in piava. The results also show changes in fish after exposure to an environmentally relevant concentration of clomazone. Most effects observed persisted after the recovery period. Thus, these parameters may be used to monitor clomazone toxicity in fish.
Chemosphere 01/2009; 74(1):1-5. · 3.21 Impact Factor
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ABSTRACT: The effects of 2,4-D (1 or 10 mg/L) on acetylcholinesterase (AChE) and metabolic parameters were evaluated in piava (Leporinus obtusidens) after 96 h. AChE activity was significantly reduced in the brain at a concentration of 10 mg/L and in the muscle at both concentrations tested. Muscle glycogen and lactate were significantly reduced for both 2,4-D concentrations but no significant change was observed in liver glycogen. Muscle protein levels were enhanced after exposure at 10 mg/L, but no significant changes were observed in muscle and liver glucose. Liver lactate and protein were significantly reduced after exposure to this herbicide. 2,4-D exposure produced a decrease in blood glucose at both concentrations and enhanced lactate levels at 10mg/L. Plasma protein increased at both concentrations tested. In conclusion, the results obtained indicate that 2,4-D affects brain and muscle AChE activity and some blood and tissue metabolic parameters of L. obtusidens. The stress generated by 2,4-D is the probable cause of alterations observed and measured parameters can be used to monitor 2,4-D fish toxicity.
Ecotoxicology and Environmental Safety 04/2008; 69(3):416-20. · 2.29 Impact Factor
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ABSTRACT: Silver catfish (Rhamdia quelen; Teleostei) were exposed to commercial formulation Roundup, a glyphosate herbicide: 0 (control), 0.2 or 0.4 mg/L for 96 h. Fish exposed to glyphosate showed an increase in hepatic glycogen, but a reduction in muscle glycogen at both concentrations tested. Glucose decreased in liver and increased in muscle of fish at both herbicide concentrations. Glyphosate exposure increased lactate levels in liver and white muscle at both concentrations. Protein levels increased in liver and decreased in white muscle while levels of ammonia in both tissues increased in fish at both glyphosate concentrations. Specific AChE activity was reduced in brain after treatments, no changes were observed in muscle tissue. Catalase activity in liver did not change during of exposure. Fish exposed to glyphosate demonstrated increased TBARS production in muscle tissue at both concentrations tested. For both glyphosate concentrations tested brain showed a reduction of TBARS after 96 h of exposure. The present results showed that in 96 h, glyphosate changed AChE activity, metabolic parameters and TBARS production. The parameters measured can be used as herbicide toxicity indicators considering environmentally relevant concentration.
Comparative Biochemistry and Physiology Part C Toxicology & Pharmacology 12/2007; 146(4):519-24. · 2.62 Impact Factor
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ABSTRACT: Effects of different herbicides on acetylcholinesterase (AChE), catalase and TBARS formation in teleost fish (Leporinus obtusidens) were studied. Fish were exposed during 30 days at concentrations of herbicides used in rice field. AChE activity in the brain decreased significantly after exposure to the herbicides clomazone and quinclorac. However, AChE activity increased significantly in muscle tissue after exposure to clomazone, propanil and metsulfuron methyl. Fish exposed to quinclorac, propanil and metsulfuron methyl showed TBARS decreased levels in brain and muscle tissues. However, TBARS and catalase activity increased in liver tissue after clomazone and propanil exposure. This study pointed out long-term effects on AChE activity, oxidative stress and antioxidant enzyme catalase in tissues of L. obtusidens after exposure to environmentally relevant concentrations of rice field herbicides. These parameters have been used to monitor fish toxicity in rice field system.
Chemosphere 08/2007; 68(8):1597-601. · 3.21 Impact Factor
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ABSTRACT: The effects of the herbicide, clomazone, on acetylcholinesterase (AChE), catalase and TBARS formation in teleost fish (Rhamdia quelen) were studied. The fish were exposed to 0.5 or 1.0 mg L(-1) of clomazone for 12, 24, 48, 96 and 192 h. After 192 h of exposure period, fish were transferred to clean water and kept in the same for 192 h to study the recovery response. Same parameters as that of exposure period were assayed after 96 and 192 h of recovery period. Specific AChE activity was reduced in the brain and muscle after treatments, reaching a maximum inhibition of 47% in the brain and 45% in the muscle after 12h of exposure. Fish exposed to clomazone increased TBARS production in the liver for all exposure periods. The brain presented elevated TBARS levels after 12, 24 and 48 h, but after 96 and 192 h, these levels decreased. The decrease of TBARS levels persisted in brain tissue after 96 h of recovery and returned to the control value after 192 h in clean water. Catalase activity was reduced for all periods of exposure. Histological analysis showed vacuolation in the liver after herbicide exposure. Some of the alterations observed were completely restored after recovery period.
Chemosphere 06/2007; 67(11):2305-11. · 3.21 Impact Factor
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ABSTRACT: In this study, teleostean fish Leporinus obtusidens (piava) were exposed to different concentrations of Roundup, a glyphosate (acid equivalent) herbicide: 0 (control), 3, 6, 10, and 20 mg/L for 96 h (short-term). Acetylcholinesterase (AChE) activity was verified in brain and muscle tissues. Metabolic parameters in the liver and muscle (lactate, glycogen, glucose, protein, and ammonia), as well as some hematological parameters, were determined. Unexposed fish exhibited significantly higher brain AChE activity when compared to that of the muscle (P<0.05) (13.8+/-0.76 and 6.1+/-1.31 micromol/min/g protein, respectively). Results indicated that AChE activity significantly decreased in the brain of fish exposed to all glyphosate concentrations tested, but in the muscle this parameter was not altered. In addition, fish exposed to all glyphosate concentrations showed a significant increase in hepatic glycogen and glucose, but a significant reduction in muscle glycogen and glucose. Lactate and protein of fish exposed to all glyphosate concentrations presented a significant decrease in the liver, but did not change significantly in the muscle. Levels of ammonia in both tissues increase in fish at all glyphosate concentrations. Exposure to this herbicide produced a decrease in all hematological parameters tested. These results indicate that AChE activity as well as metabolic and hematological parameters may be good early indicators of herbicide contamination in L. obtusidens.
Ecotoxicology and Environmental Safety 10/2006; 65(2):237-41. · 2.29 Impact Factor
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ABSTRACT: The effects of clomazone (0.5 and 1.0 mg/L) according to nominal concentrations used in paddy rice fields (0.4-0.7 mg/L) on protein and carbohydrate metabolism and haematological parameters were evaluated in silver catfish (Rhamdia quelen) after 12, 24, 48, 96 and 192 h of exposure with a recovery period of 96 and 192 h. Liver glycogen increased significantly (P<0.05) in all periods and concentrations tested. The maximum glycogen increase reaches 250% after 12h of exposure. Muscle glycogen reduced significantly after 24, 48, 96 and 192 h for both clomazone concentrations (P<0.05). Significantly elevated plasma glucose values (P<0.05) and variation in glucose in the liver and muscle of exposed fish were observed. Muscle lactate levels increased after 12, 24 and 48 h of clomazone exposure (22-67%), but reduced in the liver (P<0.05). Protein levels were enhanced in the liver and white muscle, except at 96 and 192 h of exposure, whereas it increased in the plasma in the period from 48 to 96 h (P<0.05). Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities were significantly elevated in the plasma (P<0.05). In the liver, ALT increased after 24 h, while AST activity was enhanced only after 12 h of exposure. Hematocrit contents were reduced after 96 and 192 h of exposure. Most of the metabolic disorders observed did not persist after the recovery period, except for the liver AST and ALT activity. Clomazone concentrations used in this study appear safe to fish, Rhamdia quelen, because overall parameters can be recovered after 96 and 192 h in clean water. ALT and AST activity may be an early biomarker of clomazone toxicity.
Ecotoxicology and Environmental Safety 09/2006; 65(1):48-55. · 2.29 Impact Factor
