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1.
The purpose of this study was to evaluate biochemical and morphological responses induced by carbaryl in the liver of Nile tilapia (Oreochromis niloticus) exposed during 21 days to sublethal concentrations (0.25 and 0.5 mg L−1), testing also recover for 14 days in clean water, after 14 days exposure. The activities of the following enzymes were measured: superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), glutathione reductase (GR), and reduced (GSH) and oxidized glutathione (GSSG). Globally, our data showed that exposure to carbaryl decreased the SOD, CAT, GR, and GST activities, except for the SOD and GST activities after 14 days exposure to 0.25 mg L−1. In contrast, after 14 days exposure the GR activity of the hepatic tissue from carbaryl-treated fish showed significant elevation in relation to the control. When fish were left to recover, a positive response was seen in the GSH and GSSG contents. The results of the recovery group suggest that the toxicity produced by carbaryl is reversible to some extent within 15 days. The liver histological analysis showed differences between fish concerning the cellular vacuolization degree (VD) of the hepatocytes. In fish exposed to carbaryl it was observed an increasing hepatocellular basophilia. No other histological alterations were observed when fish was exposed to carbaryl, except a few necrotic foci at day 7. The sections stained with PAS reaction showed that the vacuolization was always not due to glycogen deposits, thus suggesting lipid accumulation. The combined increased basophilia and glycogen depletion is a common, although non-specific, liver response to many toxicants. In short, this work shows a relation between histological and biochemical changes in liver and carbaryl exposure. The effects of carbaryl were observed at different concentrations.  相似文献   

2.
Abstract

Bio‐efficacy of 15 insecticides was evaluated against the pest complex of okra in the semi‐arid region of Rajasthan during July‐October, 1984. Five sprays given at intervals of 15 days throughout the crop period indicated that fenvalerate (0.02%) was most effective, followed by permethrin (0.02%), cypermethrin (0.02%), carbaryl (0.10%), monocrotophos (0.04%) and dimethoate (0.03%), against leafhoppers, aphids and fruit borer. The maximm yield of marketable fruits was obtained with fenvalerate, followed by cypermethrin, carbaryl, monocrotophos and dimethoate treatments. Highest net‐profit of Rs. 4890.00 was also recorded with fenvalerate treatment, followed by Rs. 4430.00 with carbaryl, Rs. 4148.00 with permethrin, Rs. 3977.00 with monocrotophos and Rs. 3053.00 with dimethoate treatments. A higher benfit cost ratio was found with carbaryl (1:9.78), followed by dimethoate (1:7.85), monocrotophos (1:5.18), methyl demeton (1:5.07), fenvalerate (1:3.43) and permethrin (1:2.41). These insecticides can also be used against insect pests of other vegetable crops of the season.  相似文献   

3.
Abstract: Dimethoate accumulation in liver and muscle tissues of a fresh-water fish, Clarias bactrachus L., was measured by gas liquid chromatography. Fish were exposed to a sub-lethal concentration of the pesticide in the laboratory water tank for a period of eight days. The accumulation increased up to two days, followed by decrease on the 4th and 8th days of exposure in both liver and muscle tissues. Maximum accumulation was found in liver. After eight days of exposure, fish were released into pesticide-free water to study the rate of loss of the pesticide. It was found that liver and muscle tissues were cleared of dimethoate after four and eight days respectively.  相似文献   

4.
乐果在茶叶中残留降解动态的研究   总被引：1，自引：0，他引：1  
本文是介绍有机磷农药乐果及其主要代谢物氧乐果在茶树上的残留降解动态。根据实验结果,在自然条件下,乐果在茶树芽梢上的降解速度中等。喷施800倍和1600倍药液后,芽梢中的乐果含量10天后可降至<0.5ppm和<0.05ppm。干茶中的乐果含量5天后降至<1.0ppm以至0.7ppm,9天后降至<0.1ppm。在喷施乐果的茶树芽梢上可检出其氧化物一氧乐果。喷药后3—5天达最高值,以后渐降,6—9天后即降至相似文献   

5.
This study was conducted to investigate effects of dimethoate on biochemical indices of blood (alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase activity (ALP)) and endocrine system by using serum testosterone, 17β-estradiol and cortisol levels as well as organosomatic indices (hepatosomatic index (HSI) and gonadosomatic index (GSI)) as biomarkers in sexually mature male Oncorhynchus mykiss. Prominent elevation in ALT and AST activities was determined which proved to be significantly and positively correlated with exposure concentration and period. There was no conspicuous alteration in ALP enzyme activity. Dimethoate did not show any sign of anti-androgenic effect as assessed by unaltered testosterone level. The duration and concentration dependant induction in 17β-estradiol level was observed at 5 and 15 days which was followed by significant decline at 30 days. The cortisol level showed an increasing pattern throughout the exposure period. GSI remained unchanged while pesticide treatment led to a reduction in HSI which was more pronounced with extended exposure. Present results clearly indicate that dimethoate revealed its toxicity on liver tissue by impairing membrane permeability and it has an endocrine disrupting potential possibly via acting as an estrogen mimic and modifying feedback on the hypothalamo-pituitary axis as evidenced by concomitant alteration in 17β-estradiol and cortisol levels.  相似文献   

6.
农药混剂的选择毒性研究   总被引：1，自引：0，他引：1  
稻瘟净或异稻瘟净与乐果或马拉松混用,对抗性黑尾叶蝉有明显的增效作用,对小白鼠急性口服毒性也有所增加。小白鼠口服稻瘟净或异稻瘟净后,鼠肝中水解乐果和N—甲基正己酰胺的羧酰胺酶活力明显下降;水解醋酸α-萘酯的羧酸酯酶活力也被抑制。羊肝微粒体的羧酰胺酶在体外分别被稻瘟净、异稻瘟净、磷酸三苯酯、磷酸三甲苯酯、苯硫磷、氧乐果和西维因强烈抑制,它们的I_(50)值为1.3×10~(-8)—4.0×10~(-5)克分子浓度。稻瘟净、异稻瘟净、磷酸三苯酯和西维因分别是羊肝羧酰胺酶和羧酸酯酶的竞争性抑制剂,它们的K_i值在4.8×10~(-8)—1.0×10~(-7)克分子浓度之间。这些结果表明稻瘟净、异稻瘟净等增加乐果和马拉松对哺乳动物的毒性的机制,可能主要是由于它们抑制了哺乳动物体内正常解毒乐果和马拉松的水解酶。文中讨论了这些农药混剂的选择毒性问题。  相似文献   

7.
UV-B (0.4 W m−2) irradiation and dimethoate (100 and 200 ppm) treatments, singly and in combination, declined the growth, photosynthetic pigment contents and photosynthesis (O2 evolution and CO2-fixation) of cowpea (Vigna unguiculata). Contrary to this, low concentration of dimethoate (50 ppm) caused stimulation on these parameters, while together with UV-B it showed inhibitory effects. Carotenoids (Car) showed varied responses. It was found that carbon-fixation (14CO2) was more sensitive to both the stresses than photosynthetic oxygen evolution. Photosynthetic electron transport activity was reduced by both the stresses, however, 50 ppm dimethoate besides inhibiting photosystem II (PSII) and whole chain activity, showed slight stimulation in photosystem I (PSI) activity. The individual effect of two stresses on PSII activity was probably due to interruption of electron flow at oxidation side of PSII which extended to its reaction center following simultaneous exposure. A similar trend was also noticed in case of CO2 liberation (measured as 14CO2 release) in light and dark. Results suggest that dimethoate (100 and 200 ppm) and UV-B alone caused heavy damage on pigments and photosynthetic activity of cowpea, leading to the significant inhibition in growth. Further, the interactive effects of both the stresses got intensified. However, low concentration (50 ppm) of dimethoate showed stimulation, but in combination, it slightly recovered from the damaging effect, caused by UV-B.  相似文献   

8.
The euryhaline fish, Oreochromis mossambicus was exposed to sub-lethal concentration (0.017 mg L−1) of a novel phosphorothionate, 2-butenoic acid-3-(diethoxy phosphinothionyl) ethyl ester (RPR-V) for 30 days and allowed to recover for 7 days. Important biomarker enzymes were assayed in plasma, brain, gill, liver, kidney, and muscle during exposure tenures of day-3, -7, -15, -30, and also at 7 days (withdrawal) after stopping treatment. Acetylcholinesterase (AChE) activities of brain, gill, and muscle were strongly inhibited by 67, 75, and 66%, respectively, on day-30. Exposure (time) dependent increases in alanine aminotransferase (ALAT), and aspartate aminotransferase (ASAT), acid phosphatase (AcP), and alkaline phosphatase (AkP), activities in plasma and kidney; AcP and AkP activities in gill were noticed. However, significant decrease in ALAT, ASAT, AcP, and AkP activities in liver was observed. The depletion of glycogen was observed in liver, brain, and gill tissues, an indication of typical stress related response of the fish with pesticide. A significant increase in lactate dehydrogenase (LDH) activity in gill and brain was observed and decreased in liver and muscle, indicating tissue damage and muscular harm. Depletion of glutathione (GSH) was observed in the above tissues, there by enhancing the lipid peroxidation resulting in cell damage. The induction in hepatic glutathione-S-transferase (GST) levels indicates the protection against the toxicity of xenobiotic-induced lipid peroxidation. There was a significant recovery in all the above biochemical parameters, in all the tissues of fish after a recovery period of 7 days. These results revealed that RPR-V affects the intermediary metabolism of O. mossambicus and the increase of biomarker enzymes in plasma, might be due to the necrosis of liver.  相似文献   

9.
The activity levels of glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) enzymes were estimated in liver, muscle and brain tissues of the fish, Sarotherodon mossambicus (Peters), which had been exposed to sub-lethal (3 mg litre−1) and lethal (25 mg litre−1) concentrations of the carbamate insecticide carbaryl. Based on the results obtained, the changes in GOT and GPT levels in liver, muscle and brain following different periods of sub-lethal and lethal carbaryl exposures suggested that S mossambicus showed adaptive elevation in the activity levels of the two aminotransferase enzymes in the tissues, thereby probably aiding gluconeogenesis through transamination of glucogenic amino acids to meet the energy demand under carbaryl toxicity. © 1999 Society of Chemical Industry  相似文献   

10.
Adaptive changes in the levels of carbohydrate metabolites, glucose, glycogen and lactic acid, were studied in a freshwater edible fish, Sarotherodon mossambicus exposed to a carbamate fungicide, ziram. Based on the results obtained, it was concluded that the fish showed (i) adaptive utilization of stored glycogen, particularly in liver tissue; (ii) adaptive accumulation of glycogen in muscle and heart tissues, probably by glyconeogenesis and (iii) adaptive mechanism of operation of ‘diving syndrome’, to meet the stress of the pollutant under sub-lethal exposure. © 1998 SCI.  相似文献   

11.
Daily 75 mg/kg phenobarbital ip injections for 3 days or 25 ppm dieldrin in the diet of mice for 14 days caused an increase in liver cytochrome P-450 and blood B-esterase. Liver A-esterase was not significantly increased. Under in vitro conditions, phenobarbital and dieldrin induced the oxidative as well as hydrolytic metabolism of dicrotophos, dimethoate, and phosphamidon by liver homogenates or combined microsomes plus 105,000g supernatant fractions. The concentration of dimethoxon was increased more than fourfold by the pretreatments after incubation for 4 hr at 37.5°C with NADPH added. The organophosphorus insecticides used in this study were not metabolized as well by the liver microsomes alone or 105,000g supernatant alone, as by the combination of microsomes and 105,000g supernatant. Under in vivo conditions in mice, phenobarbital and dieldrin treatments increased the urinary recovery of metabolites in the initial 6 hr after [14C]carbonyl-dimethoate or [14C]N-ethyl-phosphamidon administration. Analysis of urine showed that the inducers caused a more than sixfold increase in dimethoxon recovered and twofold increase in water-soluble nontoxic metabolites within 6 hr after dimethoate administration. With phosphamidon both inducers increased the rate of metabolism, and the total recovery in aqueous and chloroform fractions was decreased. These results suggest that increased dimethoate toxicity after phenobarbital and dieldrin treatments in whole animals results from stimulation of the activation of dimethoate to dimethoxon, while the increase in hydrolytic products after both pretreatments results in decreased toxicity of the direct acetylcholinesterase inhibitors, dicrotophos and phosphamidon.  相似文献   

12.
The sublethal effect of a synthetic pyrethroid, cypermethrin on total protein, amino acids, ammonia, glycogen, and enzymes like aminotransaminases (AIAT, AAT), glutamate dehydrogenase, and glycogen phosphorylases (a and ab) was studied in physiological important tissues viz; liver and gill tissues of freshwater teleost air breathing fish, Clarias batrachus. The study was conducted during exposure of 1/3 (33%) of LC50 concentration and followed by cessation of exposure. Thirty-six fish were exposed to 0.07 mg/L cypermethrin for 10 days. After 10 days, 18 fish were released to freshwater and kept in the same for 10 days (recovery group). Thirty-six fish were kept in freshwater as control batch. Protein content in liver tissues decreased at the end of 1st and 5th day followed by slight increase at the end of 10th day. Gill tissue showed statistical significant decrease (P < 0.001) in protein content during exposure period of 10 days. Recovery in protein content was observed to a large extent in both the tissues. Total free amino acids were increased in liver and gill tissues throughout the treatment period, recovery response was seen after cessation of exposure. Ammonia level was decrease in both the tissues throughout the exposure period except in liver tissue at the end of 1st day of exposure. Recovery response was exhibited by both the tissues. A decreased in glycogen content of liver tissue was observed during exposure period, gill tissue also showed decrease in glycogen at the end of 1st and 5th day followed by increase at the end of 10th day of exposure period. When the fish were transferred to freshwater, recovery in glycogen content was noted. The activity level of alanine, aspartate aminotransaminase, glutamate dehydrogenase, and phosphorylases (a, ab) was increased in both the tissues, followed by recovery response after released of fish into freshwater. The present study showed that cypermethrin caused alterations in certain biochemical mechanisms of C. batrachus. This fish indicated recovery response when transferred to cypermethrin free water.  相似文献   

13.
The effects of an acute lethal (0.59 mg/liter) and a sublethal (0.075 mg/liter) concentration of lindane on the levels of glycogen (liver and muscle), glucose (blood), and lactic acid (liver, muscle, and blood) of a freshwater fish, Anabas testudineus (Bloch) were determined. A marked decrease in the liver glycogen and significant increase in blood glucose and muscle glycogen at 1 hr of exposure to 0.075 mg/liter lindane was noted. These results indicate extensive utilization of energy stores in the liver and simultaneous buildup of fuel reserves in the muscle. After 3 hr of exposure, glycogenesis possibly becomes operative in liver through the Cori cycle. The activity of the cycle was observed in the fish in all the subsequent periods of exposure studied. At 120 hr, the decreases observed in muscle and liver glycogen indicate near exhaustion of glycogen stores. Though changes in glycogen content of both muscle and liver were similar in 0.59 mg/liter lindane, they have less adaptive value since mortality of fish was significantly high at all three peroids studied.  相似文献   

14.
In this study, the effects of sublethal exposures to the anticholinesterase insecticides azinphos methyl (AzMe) and carbaryl on the detoxifying responses of juvenile rainbow trout Oncorhynchus mykiss were investigated. Juvenile specimen were exposed to sublethal concentrations of AzMe (2.5 and 5 μg/L) and carbaryl (1 and 3 mg/L) for 24, 48 and 96 h. Carboxylesterase (CbE), catalase (CAT) and glutathione S-transferase (GST) activities as well as reduced glutathione (GSH) and cytochrome P450-1A (CYP1A) levels were monitored in liver and/or kidney. In all exposed groups liver CbE was significantly inhibited. Liver and kidney GSH level was reduced after sublethal exposure to both compounds. Carbaryl induced CAT activity during the first 48 h of exposure, followed by a significant decrease, whereas AzMe continuously decreased CAT activity. GST activity and CYP1A were transiently induced at 24 h by carbaryl exposure (3 mg/L) but sublethal exposure to AzMe did not affect GST activity or CYP1A. Our results show that the O. mykiss detoxifying system are a target for carbaryl and AzMe action, probably affecting redox balance. Although the responses showed similar trends in both organs, they were more important in liver than in kidney. The early inhibitory effect in CAT activity and GSH content produced by AzMe may be associated with a high degree of oxidative stress. Early induction of CYP1A, GST and CAT by carbaryl followed by enzyme inhibition suggests a milder or delayed oxidative stress, revealing differences between both pesticides metabolization. CbE inhibition is a good biomarker for AzMe and carbaryl exposure.  相似文献   

15.
Alterations in the levels of hemoglobin, total plasma proteins, glucose, and lactic acid in the blood; glycogen and lactic acid content of liver and white skeletal muscle; and the activities of lactate dehydrogenase, pyruvate dehydrogenase, and succinate dehydrogenase in liver, kidney, intestine, brain, gills, and muscles were examined in the fresh-water snake-head fish, Channa punctatus, after exposure to a sublethal concentration (25 μg/liter) of quinalphos for 60 and 120 days. Hemoglobin, plasma protein, glucose, and lactic acid decreased in pesticide-exposed fish. The glycogen content of the liver and muscles increased but lactic acid decreased. Lactate dehydrogenase activity decreased in all six tissues. Pyruvate dehydrogenase activity of liver, kidney, gill, and muscle decreased, but the enzyme activity was elevated in intestine and brain. In intestine, succinate dehydrogenase activity was elevated, and in the remaining five tissues the enzyme activity was significantly reduced. The present study showed that formation of glycogen and its breakdown was impaired in the liver, and aerobic oxidation of nutrients was adversely affected in quinalphos-exposed fish.  相似文献   

16.
The experiment was conducted to study the after effects of administering DEP at different doses to female Swiss mice for a period of 90 days. Group I mice were fed on normal diet and water ad libitum. Group II mice were maintained on normal diet mixed with corn oil at 8.25 mg/kg of the diet/day as oil control. Group III, IV and V mice were given diethyl phthalate dissolved in corn oil mixed with the diet at 10, 25 and 50 mg/kg of the diet/day, which is approximately equal to 1.25, 3.125 and 6.25 mg/kg body weight/day. A significant dose dependent increase was observed in serum acid phosphatase (ACP) whereas, serum and liver triglycerides levels showed a significant increase only in the high-dose treated group. Significant dose-dependent increase in serum aspartate and alanine aminotransferase (AST and ALT) and liver glycogen was observed. Serum lactate dehydrogenase (LDH) was significantly increased only in 25 and 50 ppm DEP-treated mice. Liver cholesterol was significantly increased in all the treated groups. Liver histology by light microscopy showed intracellular vacuolations in all the treated groups which was much more evident in the 25 and 50 ppm DEP-treated mice while hepatocellular degeneration and hypertrophy of the hepatocytes was evident in 50 ppm DEP-treated mice. Proliferation of mitochondria and peroxisomes was evident in the electron micrographs of the 10 ppm DEP-treated mice while 25 and 50 ppm DEP-treated mice showed increase in lipid droplets and severe mitochondrial proliferation.  相似文献   

17.
The effects of the chitin synthesis inhibitor (CSI) novaluron on egg hatch and on larval development ofTribolium castaneum (Herbst) concentrations of 1.0, 0.3, 0.2 or 0.1 ppm were tested. The effect of novaluron at low concentrations depended strongly on the exposure period. At 0.3 ppm, egg hatch ofT. castaneum was totally inhibited after 28 days; at 0.2 ppm the effect was much less but inhibition increased progressively to 66% in the 35-day experiment; at 0.1 ppm novaluron was ineffective. The viability of the larvae that hatched from the laid eggs and developed on untreated flour was also dependent on concentration of novaluron and exposure time: exposure ofT. castaneum adults to novaluron-treated flour at 0.3 ppm for 8 days, or at 0.2 ppm for 36 days, caused 100% or 97.5% mortality, respectively. At both 0.3 and 0.2 ppm, larval deaths were mainly in the first instar. Exposure ofT. castaneum adults to treated flour may serve as a good model for evaluating the effect of CSIs on internal feeders, especiallySitophilus oryzae (L.). The present study contributes to our understanding of CSI transovarial activity against internal stored product coleopterans whose larval stage develops inside the grain without contact with the toxicants. http://www.phytoparasitica.org posting Dec. 11, 2007.  相似文献   

18.
Previous studies have demonstrated that the anticholinesterase pesticides chlorpyrifos and carbaryl are neurotoxic to mammals. However, the toxicity of these pesticides to other organs and their potential interactive effects remain unclear. Our goal in this study was to assess the toxicities of ingestion of chlorpyrifos and carbaryl both separately, and in combination to non-nervous systems, especially the effect on urinary metabolic profiles, in rats. Chlorpyrifos, carbaryl and a mixture of these pesticides, were administered orally to Wistar rats for 90 consecutive days. Histopathological examination of liver and kidney and metabonomic analysis based on the urinary 1H nuclear magnetic resonance spectra were used to investigate the toxic effects. The results showed that no histopathological changes were observed in the liver or kidney tissues, but metabonomic analysis revealed alternations in a number of urinary metabolites involving in the energy metabolism in liver mitochondria. Treatment of rats with chlorpyrifos alone led to an increase in creatine, glycine, dimethylglycine, dimethylamine, glutamine, succinate, alanine, lactate, and glucose. The categories of main differential urinary metabolites in carbaryl-treated rats were similar to those in chlorpyrifos-treated rats, whereas the changes were of varying degree. A combination of a low dose of chlorpyrifos and carbaryl resulted in an increase in the levels of main urinary metabolites compared to the controls, and the increase in signal intensity of the main metabolites was lower than that in the rats exposed to chlorpyrifos or carbaryl alone. All above results suggest that chronic exposure to chlorpyrifos and carbaryl alone, or in combination could cause disturbance of metabolic function in liver mitochondria and renal failure. Overall, we have shown that urine metabonomic analysis is non-invasive, sensitive, and relatively fast for assessing the individual or mutual effects following exposure to pesticides.  相似文献   

19.
Doses of ten acaricides, ranging from 2.5 to 10 μg, induced about 10-60% mortality and inhibited oviposition in engorged Boophilus microplus as well as preventing larval hatching from the eggs. The effects of the acaricides were dose dependent. The efficacy of acaricides in reducing the reproductive potential (inhibition of oviposition × inhibition of hatching/100) was in the following order: dimethoate > dioxathion > naled > diazinon > chlordimeform > carbaryl > trichlorphon > phosphamidon > gamma-HCH > fenitrothion. Most of the acaricides also retarded the oviposition cycle, delaying the peak activity by 4-8 days. The ovarian development in control ticks reached its peak between the 5th and 7th days before decreasing gradually and ceasing completely between the 16-20th days after engorgement. The protein content of the ovaries and the rate of incorporation of [14C]glycine into the tissues followed a similar pattern. Carbaryl, fenitrothion and naled inhibited these activities. Chlordimeform stimulated [14C]glycine incorporation and increased the ovarian protein content up to the 13th day before resorption of the oocytes. The eggs from treated ticks were mostly non-viable and contained more protein; those from dioxathion, carbaryl and chlordimeform treatments had a higher dry weight than the control.  相似文献   

20.
Organophosphorus insecticides and ethanol individually cause free radical production induced by oxidative stress and alter the antioxidants and scavengers of free radicals. The present study indicates the effect caused by dimethoate in combination with ethanol on antioxidant status in mice. Daily, dimethoate at a dose of 18 mg/kg body weight and ethanol at 1 g/kg body weight were orally administered concurrently in a subacute study for 14 days. After the experimental period, the liver and kidney homogenates were analysed for various antioxidant enzymes. The results compared with dimethoate alone treated control indicated an increase in hepatic cytochrome P450 and lipid peroxidation. Decrease in superoxide dismutase, glutathione peroxidase, glutathione reductase, glutathione-S-transferase, and glutathione in liver was observed. In kidney, decrease in CAT, SOD, GR, GST, and GSH was observed. Acetyl cholinesterase activity of RBC was increased. No significant change was observed in catalase in liver and glutathione peroxidase in kidney. The results of the study allow us to hypothesize that dimethoate along with ethanol disturbs the antioxidant status.  相似文献   

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