The influence of the season and the biotic factors on the cytosolic metal concentrations in the gills of the European chub (Leuciscus cephalus L.)

The influence of the season and the biotic factors (age and gill mass) on metal and protein levels in the gill cytosol of the young chubs (2 and 3 years old) was studied in Sava River in autumn 2005 and spring 2006. The obtained results are the first reported cytosolic concentrations of five metals and proteins for the chub gills. The average levels in autumn and spring, respectively, for total cytosolic proteins were 11.2 and 19.9 mg ml(-1), for Zn 6.3 and 10.3 microg ml(-1), for Fe 3.9 and 9.6 microg ml(-1), for Cu 68.4 and 79.0 ng ml(-1), for Mn 55.0 and 63.5 ng ml(-1), and for Cd 2.9 and 3.6 ng ml(-1). The influence of the gill mass on both the protein and the metal levels was observed, but it was seasonally dependent. In autumn, positive correlations were obtained between the gill mass and four parameters (total proteins, Mn, Zn and Fe), and negative with Cu. Contrary, in spring, even negative correlations of total proteins and some metals with the gill mass were observed. The proposed explanation for the different dependence of metal levels on the gill mass in autumn and spring was the seasonal difference in feeding intensity and metabolic rate, with presumably faster metabolism and water filtration through gills in spring. This hypothesis was further supported by the statistically significantly higher concentrations of the total proteins, Zn and Fe, as well as the Fulton condition indices in the spring period.     

Distribution of Co,Cu, Fe,Mn, Se,Zn, and Cd among cytosolic proteins of different molecular masses in gills of European chub (Squalius cephalus L.)

The distribution of essential elements Co, Cu, Fe, Mn, Se, and Zn, and nonessential element Cd among cytosolic proteins of different molecular masses in the gills of European chub (Squalius cephalus) sampled in the moderately contaminated Sutla River in September of 2009, was studied after the protein separation by size exclusion high-performance liquid chromatography (SEC-HPLC), and the metal determination in the obtained fractions by high-resolution inductively coupled plasma mass spectrometry (HR ICP-MS). The aims of the study were to characterize the distribution profiles of metals within different protein categories in gills in the conditions of low metal exposure in the river water, and to compare them with the previously published hepatic profiles. The distribution profiles of analyzed metals were mainly characterized with several peaks. However, some observations could be emphasized: both Cu and Cd were eluted near metallothionein elution time; elution time of one of Co peaks could be associated with Co-containing compound cobalamin; increasing cytosolic Fe concentrations resulted in possible Fe binding to storage protein ferritin; both Mn and Zn had poorly resolved peaks covering wide ranges of molecular masses and indicating their binding to various proteins; both Zn and Se increased in protein fractions of molecular masses <5 kDa following their concentration increase in the gill cytosol; expected clear metallothionein peak was not observed for Zn. Comparison of gill profiles with previously published hepatic profiles revealed similar and in case of some elements (e.g., Co, Fe, Mn, and Se) almost identical distributions in both organs regarding elution times. On the contrary, heights of obtained peaks were different, indicating possible metal binding to the same proteins in the gills and liver, but in different proportions. The results obtained in this study can be used as a basis for comparison in monitoring studies, for identification of changes that would occur after exposure of chub to increased metal concentrations.     

Assessment of low-level metal contamination using the Mediterranean mussel gills as the indicator tissue

Purpose  

The aim of this study was to compare the level of metal contamination in two bays in the middle part of the Eastern Adriatic coastal zone in Croatia using the gills of mussels Mytilus galloprovincialis as indicator tissue. Despite the existing sources of contamination, previous studies with caged mussels only indicated moderate metal contamination of the Kaštela Bay, contrary to the Trogir Bay in which marina and shipyard present a probable source of Cu- and Zn-contamination.     

Relevance of biotic parameters in the assessment of the spatial distribution of gastrointestinal metal and protein levels during spawning period of European chub (Squalius cephalus L.)

The present field study, conducted during the spawning period (April/May) of European chub (Squalius cephalus L.) from the Sava River in Croatia, indicates that seasonal changes of fish physiological state might cause variability in gastrointestinal metal (Cd, Cu, Fe, Mn and Zn), total cytosolic protein and metallothionein (MT) levels. During the period of fish spawning and increased metabolic activity, a significant relationship with chub hepatosomatic index was evident for Fe and Mn in gastrointestinal tissue (r?=?0.35 and 0.26, respectively) and in cytosolic fraction (r?=?0.32 and 0.41, respectively) and for Zn and Fe in the gut content (r?=?0.36 and 0.31, respectively). Total cytosolic protein and MT concentrations followed the same spatial distribution as Fe and Mn in all gastrointestinal fractions and as Zn in the sub-cellular fractions, with higher levels at upstream locations. Due to the role of essential metals in metabolic processes and gonad development, increased feeding and spawning activity in April/May resulted in higher gastrointestinal essential metal (Fe, Mn and Zn) and MT concentrations, which probably follow an increase in Zn concentrations, known as the primary MT inducer. Therefore, biotic factors should be considered as important confounding factors in metal exposure assessment, while their influence on gastrointestinal metal and protein levels should be interpreted depending on the season studied.     

Analysis of lipid peroxidation in animal and plant tissues as field-based biomarker in Mediterranean irrigated agroecosystems (Extremadura,Spain)

ABSTRACT

The development of field-based biomarkers can allow for a more reliable assessment of the exposure of organisms to pollutants. Different sampling sites, along two streams running through an irrigable agricultural area, were selected to evaluate the effect of agrochemical load on the measured endpoints. The levels of lipid peroxidation were evaluated in several organs of Procambarus clarkii. The same method was applied to leaves of two woody species. Determining levels of MDA (malonaldehyde) by thiobarbituric acid reactive substances assay allows measuring the levels of lipid peroxidation. Differences in lipid peroxidation levels were observed in P. clarkii individuals collected at different sites; however, the patterns varied depending on the organ (when accounting for variations due to sex). The use of a MDA-gills/MDA-hepatopancreas index allowed for discrimination between reference and polluted sites. Significant differences in oxidative damage between sites were found in the leaves of Quercus rotundifolia but not in Salix sp. The lipid peroxidation of crayfish organs and holm oak leaves as a suitable biomarker of environmental pollution deserves further investigation.     

Malondialdehyde and heavy metal concentrations in tissues of wild boar (Sus scrofa L.) from central Croatia

The aim of this research was to assess the degree of heavy metal (cadmium, lead and mercury) contamination of wild boars from central Croatia and thereby conduct further tests to connect the contamination to oxidative stress occurrence. The highest cadmium concentration was noticed in the kidneys of older boars, the lead concentration was approximately the same in the liver and kidneys, but it was much higher than the concentration in the muscles, while the highest mercury concentration was measured in the kidneys of all wild boars. The correlation between the malondialdehyde (MDA) and the heavy metal concentrations was higher in tissue samples taken from younger animals (1 to 3 years of age) than in the tissue samples taken from older animals (5 to 6 years of age). In the kidneys of all wild boars there was a statistically significant connection between the MDA and cadmium concentration; in the kidneys of younger wild boars there was a statistically significant connection between the MDA and lead concentration. Further research on this topic should focus on MDA potential to find its use, not only as a contamination biomarker in the area of ecotoxicology, but also in the evaluation of the hygienic acceptability of animal products.     

Determination of lipid peroxidation and cytotoxicity in calcium, magnesium, titanium and hectorite (SHCa-1) suspensions

This paper reports data on the relative ability of CaO, CaCl₂, MgO, MgCl₂, TiO₂, and hectorite (SHCa-1) to induce oxidative stress (as determined by lipid peroxidation, LP) in biological matrices. The effectiveness of structural (oxide form) versus soluble Ca and Mg to induce LP is compared. An assessment on cytotoxicity as affected by soluble and structural Ca, Mg, TiO₂ and SHCa-1 is also addressed. LP was screened and monitored using the Thiobarbituric Acid Reactive Substances (TBARS). The extent of TBARS production was found to vary with the type and initial concentration of the soluble or structural cation, Ca or Mg respectively. Obtained results showed higher magnitude values for the latter set of experiments. In the presence of TiO₂ no significant TBARS production was detected pointing out a negligible effect of TiO₂ on LP. At solid concentrations ca. 100 ppm, CaO appears to be more effective than SHCa-1 to induce LP. By contrast at ca. 25 ppm, MgO appears to be more effective than the clay mineral. The SHCa-1 LP-inducing activity has been proven to closely relate to structural Ca. The prevalence of mechanisms that may induce LP but not cytotoxicity (as determined by cell growth inhibition) was also addressed. Results on cell growth inhibition as affected by soluble and structural Ca, Mg, TiO₂ and hectorite provide evidence to support that structural Ca or Mg brings about significantly higher variations than soluble Ca.     

Copper and zinc induction of lipid peroxidation and effects on antioxidant enzyme activities in the microalga Pavlova viridis (Prymnesiophyceae)

The metal-induced lipid peroxidation and response of antioxidative enzymes have been investigated in the marine microalga Pavlova viridis to understand the mechanisms of metal resistance in algal cells. We have analyzed superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) activities and glutathione (GSH) contents in microalgal cells grown at different concentrations of copper and zinc. In response to each metal, lipid peroxidation was enhanced with the increase of concentrations, as an indication of the oxidative damage caused by metal concentration assayed in the microalgae cells. Exposure of P. viridis to the two metals caused changes in enzyme activities in a different manner, depending on the metal assayed: after copper treatments, total SOD activity was enhanced, while it was reduced after zinc exposure. Copper and zinc stimulated the activities of CAT and GSH whereas GPX showed a remarkable increase in activity in response to copper treatments and decrease after zinc treatments. These results suggest that an activation of some antioxidant enzymes was enhanced to counteract the oxidative stress induced by the two metals.     

Distribution of selected essential (Co, Cu, Fe, Mn, Mo, Se, and Zn) and nonessential (Cd, Pb) trace elements among protein fractions from hepatic cytosol of European chub (Squalius cephalus L.)

Association of selected essential (Co, Cu, Fe, Mn, Mo, Se, and Zn) and nonessential (Cd, Pb) trace elements with cytosolic proteins of different molecular masses was described for the liver of European chub (Squalius cephalus) from weakly contaminated Sutla River in Croatia. The principal aim was to establish basic trace element distributions among protein fractions characteristic for the fish living in the conditions of low metal exposure in the water. The fractionation of chub hepatic cytosols was carried out by size exclusion high performance liquid chromatography (SE-HPLC; Superdex? 200 10/300 GL column), and measurements were performed by high resolution inductively coupled plasma mass spectrometry (HR ICP-MS). Elution profiles of essential elements were mostly characterized by broad peaks covering wide range of molecular masses, as a sign of incorporation of essential elements in various proteins within hepatic cytosol. Exceptions were Cu and Fe, with elution profiles characterized by sharp, narrow peaks indicating their probable association with specific proteins, metallothionein (MT), and ferritin, respectively. The main feature of the elution profile of nonessential metal Cd was also single sharp, narrow peak, coinciding with MT elution time, and indicating almost complete Cd detoxification by MT under the conditions of weak metal exposure in the water (dissolved Cd concentration ≤0.3 μg L^?1). Contrary, nonessential metal Pb was observed to bind to wide spectrum of proteins, mostly of medium molecular masses (30–100 kDa), after exposure to dissolved Pb concentration of ~1 μg L^?1. The obtained information within this study presents the starting point for identification and characterization of specific metal/metalloid-binding proteins in chub hepatic cytosol, which could be further used as markers of metal/metalloid exposure or effect on fish.     

Species-dependent chromium accumulation, lipid peroxidation, and glutathione levels in germinating kiwifruit pollen under Cr(III) and Cr(VI) stress

The accumulation of chromium by germinating kiwifruit pollen appears to be significantly affected by Cr species, Cr concentration and calcium availability. Cr(III) accumulation always occurred in a linear manner while Cr(VI) uptake followed a logarithmic model. In the absence of exogenous calcium, Cr(III) accumulation was much higher than that of Cr(VI). It was observed that, as the Cr(III) concentration increased, there was a significant decrease in the endogenous calcium content of pollen, ultimately leading to complete calcium depletion after 90 min of incubation at 150 microM Cr(III). This loss of calcium could be responsible for the strong inhibition of tube emergence and growth following exposure of pollen to Cr(III). Indeed, when exogenous calcium was added to the kiwifruit pollen culture medium, significant growth recovery and reduced Cr(III) uptake occurred; the opposite was true in Cr(VI)-treatments. A significant rise in lipid peroxide production occurs in the presence of both Cr species; the effect was more pronounced following Cr(VI) exposure. Finally, glutathione pool dynamics appears to be differentially affected by chromium species and concentrations. In conclusion, results of the present study have provided important information regarding the different activity profiles of Cr(III) and Cr(VI) in relation to kiwifruit pollen performance, and have also demonstrated differences in some biochemical responses of pollen to metal stress.     

The measurement of cholinesterase activities as a biomarker in chub (Leuciscus cephalus): the fish length should not be ignored

Biomarkers are early warning systems of the exposure of aquatic organisms to pollutants. Among them, the measurement of the cholinesterase (ChE) activities in fish muscle is a biomarker of the exposure to organophosphosphates and carbamates pesticides. As such it has been used in numerous field studies both in marine and continental waters. Cyprinids (chub, Leuciscus cephalus) were sampled in river sites (France) in relatively clean and polluted areas. We performed the statistical analysis of the ChE activities and we generally observed a statistical relationship between ChE activities and fish length, the larger fish having the lower ChE activities. We concluded that the great majority of the significant differences in ChE activities between sites could be due in fact to differences in fish length between field samples. We stress the importance of taking into account the fish length whenever differences in ChE levels between field sites must be interpreted.     

Serum concentrations of indicator PCB congeners in the Czech adult population

In 2006, levels of seven indicator polychlorinated biphenyl congeners (PCB28, 52, 101, 118, 138, 153, and 180) in blood serum of 202 blood donors residing for more than 2 years in five urban areas included in the Czech Human Biomonitoring project were measured by GC/MS/MS method. PCB congeners 138, 153 and 180 accounted for about 97% of the sum of the indicator congeners analyzed. Overall, the median and 95th percentile of the most abundant congener PCB 153 were 438 ng/g lipid and 1079 ng/g lipid, respectively. The highest median levels were found in Uherské Hradiste (669 ng/g lipid) and Ostrava (672 ng/g lipid in males compared to 341 ng/g lipid in females). Serum PCB concentrations were significantly associated with age, gender, place of residence and smoking habit, but not with body mass index and education. The results suggest the importance of PCB body burden in the Czech general population and the existence of hot spots.     

Mercury induced time-dependent alterations in lipid profiles and lipid peroxidation in different body organs of cat-fish Heteropneustes fossilis

The effects of mercuric chloride (HgCl2) on lipid profiles and lipid peroxidation in different body organs of fresh water cat-fish Heteropneustes fossilis were studied. The daily exposure of HgCl2 0.2 mg/L for 10, 20 and 30 days depleted the total lipids in brain. But the content of phospholipids enhanced significantly at 30 days. Significant diminution in C/P ratio was discernible with 30 days of exposure following mercury toxicosis. Liver exhibited elevated levels of total lipids, phospholipids, cholesterol and C/P ratio. Interestingly kidney showed marked decrease in the concentration of total lipids, cholesterol and C/P ratio at higher exposure. However, the phospholipid values increased during the longer exposure. The content of total lipids and phospholipids was high in muscle but the level of cholesterol and C/P ratio were depleted. Significant increment in lipid peroxidation was discernible in brain, liver and muscle. In kidney the rate of lipid peroxidation was significantly reduced. The results suggest that exposure of HgCl2 enhances the peroxidation of endogenous lipids in brain, liver and muscle. Interestingly the lipid contents are affected differently in different body organs.     

Organophosphate dichlorvos induced dose-related differential alterations in lipid levels and lipid peroxidation in various regions of the fish brain and spinal cord

The effect of dichlorvos (DDVP) (0-0, dimethyl 2:2-dichlorovinyl phosphate), on various lipid fractions and lipid peroxidation in the discrete areas of the brain and spinal cord were studied in the fresh water teleost (Heteropneustes fossilis). Fishes were exposed to three different doses (3.0, 6.0 and 9.0 ppm) of DDVP daily for 7 days. Dose-related increase in the levels of total lipids, cholesterol and esterified fatty acids was detected in the fore brain, optic lobes, cerebellum, medulla oblongata and spinal cord. However, phospholipids were significantly decreased in the aforementioned regions of the central nervous system. The rate of lipid peroxidation was significantly increased in all the regions of the CNS.     

Oxidative stress and lipid peroxidation in the earthworm Eisenia fetida induced by low doses of fomesafen

Formesafen is a diphenyl ether herbicide that has adverse effects on non-target animals. However, knowledge about the effect of fomesafen on the antioxidant defense system in earthworms is vague. Thus, it is essential to investigate the effects of fomesafen on the antioxidant defense system in earthworms as a precautionary method. In the present study, earthworms (Eisenia fetida) were exposed to artificial soil treated with a range of concentrations of fomesafen (0, 10, 100, and 500 μg kg^?1) and were collected on the 3rd, 7th, 14th, 21st, and 28th days of exposure. Subsequently, the antioxidant enzyme activities (superoxide dismutase (SOD); catalase (CAT); and guaiacol peroxidase (POD)), reactive oxygen species (ROS) level, and malondialdehyde (MDA) content due to fomesafen treatment were examined in earthworms. Compared with the control, the SOD activity increased on the third and seventh days but decreased on the 14th day due to treatment with 100 and 500 μg kg^?1 of fomesafen. The activities of CAT and POD increased significantly on the third, seventh, and 14th days of exposure. In addition, the ROS level was significantly enhanced throughout the entire experimental period and showed a statistically dose-dependent relationship on the seventh and 14th days. The MDA content markedly increased on the seventh day of exposure; however, obvious changes were not detected at other exposure period. Low doses of fomesafen (≤500 μg kg^?1) may result in oxidative damage and lipid peroxidation in E. fetida by inducing the generation of ROS at short exposure periods (14 days). However, the adverse effects of fomesafen gradually disappear as the cooperation of antioxidant enzymes and exposure time are prolonged. This result may be helpful for further studies on the toxicological mechanisms of fomesafen to earthworms.     

Effect of heavy metal stress on antioxidative enzymes and lipid peroxidation in leaves and roots of two mangrove plant seedlings (Kandelia candel and Bruguiera gymnorrhiza)

The effects of multiple heavy metal stress on the activity of antioxidative enzymes and lipid peroxidation were studied in leaves and roots of two mangrove plants, Kandelia candel and Bruguiera gymnorrhiza, grown under control (10 per thousand NaCl nutrient solution) or five levels of multiple heavy metal stress (10 per thousand NaCl nutrient solution containing different concentration of Pb2+, Cd2+, and Hg2+). Leaves and roots of control and heavy metal-stressed plants were harvested after two months. In leaves of heavy metal-stressed plants superoxide dismutase (SOD) and peroxidase (POD) activities fluctuated in different stress levels compared to the control, while catalase (CAT) activity increased with stress levels in K. candel, but remained unchanged in leaves of B. gymnorrhiza. In comparison with the control, the dynamic tendency of SOD, CAT, and POD activities in roots of heavy metal-stressed plants all ascended, and then declined. The increase in enzyme activities demonstrated that K. candel is more tolerant to heavy metals than B. gymnorrhiza. Lipid peroxidation was enhanced only in leaves of heavy metal-stressed B. gymnorrhiza. These results indicate that in heavy-metal stress antioxidative activities may play an important role in K. candel and B. gymnorrhiza and that cell membrane in leaves and roots of K. candel have greater stability than those of B. gymnorrhiza. For pollution monitoring purposes, POD activity in roots and leaves maybe serve as a biomarker of heavy metal stress in K. candel, while lipid peroxidation maybe serve as biomarker in B. gymnorrhiza.     

Iron-mediated reactions of polychlorinated biphenyls in electrochemical peroxidation process (ECP)

A study was conducted to explore some of the basic processes of polychlorinated biphenyl (PCB) destruction by a new technology termed electrochemical peroxidation process (ECP). ECP represents an enhancement of the classic Fenton reaction (H2O2 + Fe2+) in which iron is electrochemically generated by steel electrodes. Focus was on the extent of adsorption of a mixture of Aroclor 1248 on steel electrodes in comparison to iron filings. Commercially available zero-valent iron filings rapidly adsorbed PCBs from an aqueous solution of Aroclor 1248. Within 4 h, all the PCBs were adsorbed at 1%, 5%, and 10% Fe0 (w/v) concentrations. Little difference in adsorption was found between acidic (2.3) and unamended solutions (pH 5.5), even though significant differences in iron oxidation state and Fe2+ concentrations were measured in solution. PCB adsorption also occurs on steel electrodes regardless of the pH or electric current applied (AC or DC), suggesting the combination of oxidizing (free radical-mediated reactions) and reducing (dechlorination reactions) iron-mediated degradation pathways may be possible. Extraction of the iron powder after 48 h of contact time yielded the progressive recovery of biphenyl with increasing Fe mass(from 0.4% to 3.5%) and changes of the PCB congener-specific pattern as a consequence of dechlorination. A variety of daughter congeners similar to those accumulated during anaerobic microbial dechlorination of Aroclor 1248 in contaminated sediments indicate preferential removal of meta- and para-chlorines.     

Chromium induced lipid peroxidation in the plants of Pistia stratiotes L.: role of antioxidants and antioxidant enzymes

In the plant, Pistia stratiotes L., the effect of different concentrations of chromium (0, 10, 40, 80 and 160 microM) applied for 48, 96 and 144 h was assessed by measuring changes in the chlorophyll, protein, malondialdehyde (MDA), cysteine, non-protein thiol, ascorbic acid contents and superoxide dismutase (SOD), ascorbate peroxidase (APX) and guiacol peroxidase (GPX) activity of the plants. Both in roots and leaves, an increase in MDA content was observed with increase in metal concentration and exposure periods. In roots, the activity of antioxidant enzymes viz. SOD and APX increased at all the concentrations of Cr at 144 h than their controls. The GPX activity of the treated roots increased with increase in Cr concentration at 48 and 96 h of exposures, however, at 144 h its activity was found declined beyond 10 microM Cr. The level of antioxidants in the roots of the treated plant viz. cysteine and ascorbic acid was also found increased at all the concentrations of Cr at 144 h than their respective controls, however, an increase in the non-protein thiol content was recorded up to 40 microM Cr followed by decrease. The chlorophyll content decreased with increase in Cr concentrations and exposure periods. However, the protein content of both roots and leaves were found decreased with increase in Cr concentrations at all the exposure periods except an increase was recorded at 10 microM Cr at 48 h. In Cr treated plants, the no observed effect concentration (NOEC) and lowest observed effect concentration (LOEC) for leaves chlorophyll and protein contents were 40 and 80 microM Cr, respectively after 48 h exposure while NOEC and LOEC for root protein content were 10 and 40 microM, respectively after 48 h. The analysis of correlation coefficient data revealed that the metal accumulation in the roots of the plant was found positively correlated with antioxidant parameters except SOD after 48 h of exposure, however, negatively correlated with most of all the parameters studied at 144 h in both part of the plant. It may be suggested from the present study that toxic concentrations of Cr cause oxidative damage as evidenced by increased lipid peroxidation and decreased chlorophyll and protein contents. However, the higher levels of enzymatic and non-enzymatic antioxidants suggest the reason for tolerating higher levels of metals.     

Cytotoxic effect of fenitrothion and lambda-cyhalothrin mixture on lipid peroxidation and antioxidant defense system in rat kidney

A mixture of pyrethroids plus organophosphates was assessed for their potential effects on lipid peroxidation, the antioxidant defense system and lactate dehydrogenase (LDH) in rat kidney in vitro. Various insecticide concentrations were incubated with kidney homogenate at 37°C for different incubation times. Treatment with fenitothion (FNT) plus lambda-cyhalothrin (LC) caused a significant induction (P < 0.05) in thiobarbituric acid reactive substances (TBARS), which might be associated to decreased levels of reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST) activities and protein content in rat kidney. However, a significant induction of lactate dehydrogenase (LDH) activity was observed. The effect was concentration and time dependent. It can be concluded that depletion of GSH might indicate that reactive oxygen species (ROS) could be involved in the toxic effects of FNT plus LC which lead to marked perturbations in antioxidant defense system.     

Cytotoxic effect of fenitrothion and lambda-cyhalothrin mixture on lipid peroxidation and antioxidant defense system in rat kidney

A mixture of pyrethroids plus organophosphates was assessed for their potential effects on lipid peroxidation, the antioxidant defense system and lactate dehydrogenase (LDH) in rat kidney in vitro. Various insecticide concentrations were incubated with kidney homogenate at 37°C for different incubation times. Treatment with fenitothion (FNT) plus lambda-cyhalothrin (LC) caused a significant induction (P < 0.05) in thiobarbituric acid reactive substances (TBARS), which might be associated to decreased levels of reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST) activities and protein content in rat kidney. However, a significant induction of lactate dehydrogenase (LDH) activity was observed. The effect was concentration and time dependent. It can be concluded that depletion of GSH might indicate that reactive oxygen species (ROS) could be involved in the toxic effects of FNT plus LC which lead to marked perturbations in antioxidant defense system.