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1.
Male feral pigeons were dosed with ring-labeled [14C]p,p′-DDT and the tissues and droppings analyzed for total 14C, extractable 14C, and metabolites. Only 16% of an intraperitoneal dose of 1.5–2.2 mg kg?1 was voided in the droppings over 28 days; the rate of loss reached a maximum on the 14th day and then fell quickly away. The rate of removal of 14C in droppings was low in comparison to that found in the rat and the Japanese quail. When pigeons were dosed with 32–38 mg kg?1 DDT per bird, and killed after 77 days, 5.4% of the dose was eliminated in droppings and 87% was recovered in the body. The tissues and droppings from this experiment were analyzed for DDT and its metabolites. Of the 14C remaining in tissues 88% was accounted for as the apolar compounds DDE, DDT, and DDD. Approximately half of the 14C in droppings was present as DDE, DDT, and DDD, whereas 27–35% was apparently in conjugated form, extractable from aqueous solutions by ethyl acetate after prolonged acid hydrolysis. Two polar metabolites were isolated from the acid-released material. One was p,p′-DDA; the other was extractable from aqueous solution at pH 8 and was tentatively identified as a monohydroxy derivative of p,p′-DDT. DDE accounted for 93% of the 14C present as metabolites in tissues and droppings, clearly indicating the importance of this intermediate in this study. The metabolism of DDT in the feral pigeon is discussed in relation to its metabolism by other species.  相似文献   

2.
Cell suspension cultures of wheat and soybean were incubated with [14C]-1,1,1-trichloro-2,2-bis-(4-chlorophenyl)ethane (DDT), [14C]-1,1-dichloro-2,2-bis-(4-chlorophenyl)ethene (DDE), and [14C]-2,2-bis-(4-chlorophenyl)acetic acid (DDA) under standardized conditions. Polar metabolites were formed in yields of 1–2.5% in the cases of DDT and DDE, and of 56% in the case of DDA. A nonpolar metabolite was only observed in the case of DDT in soybean. This metabolite was identified as DDE on the basis of cochromatography and mass spectroscopy. By the same methods DDA was identified as a major polar DDT metabolite of both soybean and wheat. The further conversion of DDA to hexose esters was demonstrated by chromatographic and mass spectroscopic comparison with synthetic DDA-β-d-glucopyranosyl tetraacetate. These studies suggest the metabolic sequence, DDT → DDA → DDA-hexose ester.  相似文献   

3.
Volatilization, mineralization, degradation and binding of soil-applied [14C]DDT were studied in three different soils from a tropical region of southern India subjected to solar irradiation and flooding for a period of 42 days. The soil types–red cotton soil, nursery soil and canal bank soil–differed in their organic carbon content, pH and texture. Under unflooded conditions, volatile losses were highest in the sandy canal bank soil. Flooding significantly enhanced volatilization, and this effect was maximal in the nursery soil, which had the highest organic carbon. The soils fully exposed to solar radiations in quartz tubes registered 1.5-1.8 times greater volatility. The volatilized organics contained appreciable quantities of DDE under both flooded and unflooded conditions. In addition, greater quantities of DDD volatilized from the flooded systems. The rate of formation of DDE was faster when soils were irradiated in quartz tubes. Mineralization remained minimal throughout the period of exposure and flooding the soil appeared to reduce further the [14C]carbon dioxide evolution. Canal bank soil exhibited the least mineralization and degradation. The data indicate that volatilization was significantly influenced by solar radiation and flooding to a much greater degree than by the differences in soil properties. Binding of DDT to soil was significantly increased by flooding the soil, thus leaving up to 33% of the initial DDT as bound residues in the nursery soil.  相似文献   

4.
Resistance to 4,4′-dichlorodiphenyltrichloroethane (DDT) in the 91-R strain of Drosophila melanogaster is extremely high compared to the susceptible Canton-S strain (>1500 times). In addition to enhanced oxidative detoxification, the 91-R strain also has a reduced rate of DDT penetration, increased levels of reductive and conjugative metabolism, and substantially more excretion than the Canton-S strain. Contact penetration of DDT was ∼30% less with 91-R flies, which also had significantly more cuticular hydrocarbons and a thicker, more laminated cuticle compared to Canton-S flies, possibly resulting in penetration differences. DDT was metabolized ∼1.6-fold more extensively by 91-R than Canton-S flies, resulting in dichlorodiphenyldichloroethane (DDD), two unidentified metabolites and polar conjugates being formed in significantly greater amounts. 91-R flies also excreted ∼4-fold more DDT and metabolites than Canton-S flies. Verapamil pretreatment reduced the LD50 value for 91-R flies topically dosed with DDT by a factor of 10-fold, indicating that the increased excretion may involve, in part, ATP-binding cassette (ABC) transporters. In summary, DDT resistance in 91-R is polyfactorial and includes reduced penetration, increased detoxification and direct excretion.  相似文献   

5.
Pigeons, Bengalese finches, and Japanese quail were dosed with pure pp′DDT, and their tissues were examined for residues immediately after death, or following storage. DDD residues in livers extracted immediately after death were always low (<5% DDT concentration) and sometimes undetectable. Reductive dechlorination of DDT to DDD occurred postmortem, relatively repidly at 20°C (90% after 8 hr), but more slowly at ?10 and ?20°C. The conversion could not be attributed to bacterial action and was evidently due to processes operating within the cell under anaerobic conditions. During storage at ?12 to ?15°C, reductive dechlorination occurred in brain and in embryos, but did not occur to any significant extent in depot fat or in eggs without embryos. These findings raise questions about the importance of DDD as an in vivo metabolite in birds and other vertebrates. The interpretation of DDD residues in tissues from laboratory and field studies is discussed.  相似文献   

6.
Exuviella baltica, a marine dinoflagellate, was exposed to DDE, the major metabolite of DDT, at a concentration of 25 μg/liter of medium. At intervals of 1 hr and 1, 2, 3, and 4 days, cells were withdrawn from the culture, washed, and reseeded in DDE-free medium, and their growth (cell division) and photosynthesis were monitored for 14 days. No increase in cell numbers occurred until cells were removed from DDE, and lag phases, proportional to the duration of DDE exposure and lasting up to 5 days, preceded exponential growth. Cell densities comparable to controls were eventually reached in all treated cultures. A similar pattern of 14C uptake per milliliter of culture and per cell was observed. A 1-hr exposure to DDE resulted in a maximum reduction of 45% in carbon fixed per cell, while longer exposures caused reductions as great as 91%, relative to controls.  相似文献   

7.
The mode of action of DDT and pyrethroids was investigated in the house fly, Musca domestica L, using drug:receptor binding techniques. Both in vivo and in vitro binding studies demonstrated the existence of membrane receptors which bind specifically to [14C]DDT and [14C]cis-permethrin. The receptors show properties to be expected of a critical target site of these insecticides. These include negative temperature correlation with binding, relatively nonsensitivity to DDE, and sensitivity to Ca2+. The receptor sites are readily saturated at 45–90 nM [14C]DDT and have an apparent disassociation constant (Kd) of 12.2 nM. The maximum number of binding sites was estimated to be 17 pmol DDT/mg membrane protein (0.34 pmol/house fly head). Competition studies showed DDT, cis-permethrin, and cypermethrin bind to the same receptor but not at precisely the same site. The addition of Ca2+ to the incubation buffer significantly inhibited the binding of both [14C]DDT and [14C]cis-permethrin, suggesting the receptor binding is Ca2+ sensitive and may have a role in ion conductance.  相似文献   

8.
Organochlorine residues in wings of adult mallards and black ducks were monitored during the 1972-73 hunting season. DDE, DDT, DDD, dieldrin, and polychlorinated biphenyls (PCB's) were present in all samples. Mallard wings from Alabama contained the highest mean levels of DDE, DDT, DDD, dieldrin, and PCB's. Mallards and black ducks from the Atlantic Flyway and mallards from the Pacific Flyway contained significantly lower DDE residues than in 1969-70. Black ducks from the Atlantic Flyway contained significantly less dieldrin than in 1969-70, and mallards in the Central and Pacific Flyways contained significantly lower levels of PCB's. As in 1969-70, DDE residues were lowest in the Central Flyway and highest in the Atlantic Flyway. The average PCB level remained unchanged in the Atlantic Flyway but was higher in the Mississippi Flyway than in 1969-70, probably because of the unusually high levels in Alabama samples. All organochlorine residues in black ducks from the Atlantic Flyway significantly correlated. DDE concentrations in mallards from the Atlantic Flyway significantly correlated with those of DDT, DDD, and PCB's.  相似文献   

9.
The excretion patterns and tissue residues were determined after single and repeated oral dosing of rats with triazophos-14C Within 4 days after a single oral dose 76.3 % of the 14C was excreted in the urine and 21.0% in the faeces. After daily application for 12 days 69.5–83.4% of the label was eliminated in urine and 30.9–18.1 % in the faeces. Following prolonged application, however, elimination is distinctly slower. Distribution of radioactive residues in organs and tissue in both test series showed no appreciable or critical concentrations of radioactivity, with the exception of the gastrointestinal tract (contents and walls). Unchanged triazophos and l-phenyl-1,2,4-triazol-3-ol-3-14C were excreted in the faeces. Renewed release of other metabolites into the gastrointestinal tract apparently does not take place. The following metabolites are detected in the urine: urea-14C (approx. 85% of the radioactivity excreted with the urine); and three compounds as conjugates with glucuronic acid, i.e. 1-phenyl-l,2,4-triazol-3-ol-3-14C (approx. 3%), l-phenylsemicarbazide-3-14C (approx. 5%), and semicarbazide-14C (approx. 5%). Two further metabolites, so far unidentified, occurred in small quantities.  相似文献   

10.
Fourth instar larvae, the progeny from wild-caught Anopheles sacharovi females, were subjected to a number of biochemical tests and the results were compared to those from similar tests on laboratory insecticide resistant and susceptible strains of anopheline and culicine mosquitoes. DDT resistance in An. sacharovi is associated with the ability to rapidly metabolise DDT to DDE. The organophosphorus and carbamate resistance was not associated with quantitative changes in esterases, multifunction oxidases, or glutathione S-transferase. The acetylcholinesterase was less sensitive to malaoxon and propoxur than laboratory susceptible An. albimanus, and plots of inhibition suggest that the population was polymorphic for more than one form of acetylcholinesterase. Metabolism studies on malathion and pirimiphos methyl did not indicate resistance due to increased metabolism. There was no evidence of penetration barriers contributing to resistance to either DDT or malathion, and there was no indication of any resistance to pirimiphos methyl in our tests.  相似文献   

11.
Aqueous suspensions and oil emulsions of a commercial [14C]diflubenzuron (N-[[(4-chlorophenyl)amino]carbonyl]-2,6-difluorobenzamide) formulation (Dimilin W-25) remained on the leaf surface of greenhouse-treated plant tissues. Absorption, translocation, and metabolism of the [14C]diflubenzuron were not significant. Less than 0.05% of the applied 14C was found in newly developed plant tissues 28 days after spray treatment. [14C]Diflubenzuron was degraded in soil. After 91 days, biometer flask studies showed that 28% of the 14C incorporated into the soil as [14C]diflubenzuron was recovered as 14CO2. Major dichloromethane-soluble soil residues were identified as unreacted [14C]diflubenzuron and [14C]4-chlorophenylurea. A minor unknown degradation product cochromatographed with 2,6-difluorobenzoic acid. Insoluble 14C-residues increased with time and represented 67.8% of the residual 14C in the soil 89 days after treatment. Cotton plants grown for 89 days in [14C]diflubenzuron-treated soil contained only 3% of the 14C applied to the soil. Small quantities of acetonitrile-soluble [14C]4-chlorophenylurea were isolated from the foliar tissues. Root tissues contained small amounts of [14C]diflubenzuron and trace quantities of a minor 14C-product that chromotographed similarly to 2,6-difluorobenzoic acid. Most of the 14C in the plant tissues (84–93%) was associated with an insoluble residue fraction 89 days after treatment.  相似文献   

12.
Intact mitochondria, isolated from red coxal muscle of the American cockroach (Periplaneta americana L.), were incubated in the presence of 1,1,1-trichloro-2,2-bis(4-chloro[14C]phenyl)ethane ([14C]DDT) to isolate a suspected binding site for DDT in the membrane sector of the mitochondrial ATPase. The requirements for the binding of DDT were compared with those for the binding of dicyclohexyl[14C]carbodi-imide([14C]DCCD), a potent inhibitory probe of mitochondrial ATPase activity. [14C]DDT appeared to bind to a proteolipid of the membrane sector, which also binds [14C]DCCD. Exchange experiments, with [14C]DCCD, [14C]DDT and unlabelled DDT at different concentrations, indicated that DDT and DCCD may be acting on a similar protein. This protein may act as the energy transducing protonophore required for the synthesis and hydrolysis of ATP in coupled mitochondria. Inhibition of mitochondrial ATPase activity may be a consequence of DDT and DCCD binding to this proteolipid protonophore, resulting in the disruption of energy transduction in muscle and nerve.  相似文献   

13.
Metabolism of [phenyl-14C] and [(2,5) pyrrolidine-14C] cisanilide was investigated in vitro with microsomal preparations from rat liver. Microsomal activity was associated with a mixed-function oxidase system that required O2 and NADPH and was inhibited by CO. Two major ether-soluble metabolites were isolated. They were identified as primary oxidation products: 2-hydroxy-2,5-dimethyl-1-pyrrolidinecarboxanilide (A) and 4′-hydroxy-2,5-dimethyl-1-pyrrolidinecarboxanilide (B). Minor ether-soluble metabolites were also isolated. Precursor product studies and qualitative thin layer chromatography analysis of [pyrrolidine-14C] and methylated [phenyl-14C] hydrolysis products suggested that these metabolites were secondary oxidation products formed from metabolites A or B. One of these metabolites appeared to be the dihydroxy product 2,4′-dihydroxy-2,5-dimethyl-1-pyrrolidinecarboxanilide. Crude microsomal preparations (postmitochondrial supernatant fractions) also formed small quantities (<10%) of polar metabolites. Enzyme hydrolysis with β-glucuronidase (Escherichia coli) indicated that approximately 50% of these metabolites were glucuronides. Similarities and differences in cisanilide oxidation in vivo in plants and in vitro with rat liver microsomal preparations were discussed.  相似文献   

14.
The effects of octylphenol (OP) and four of its ethoxylated derivatives on uptake into, and distribution within, maize leaf of 2-deoxy-glucose (2D-glucose), atrazine and o, p′-DDT are reported. The surfactants and OP (2 g litre?1 in aqueous acetone) increased the uptake, at both 1.5 and 24 h, of the three model compounds (applied at 1 g litre?1) having water solubilities in the g, mg and μg litre?1 ranges. The uptake of 2D-glucose was positively correlated with the hygroscopicity of the surfactants. The uptake of DDT and atrazine increased with the uptake of the surfactants, being inversely related to their hydrophile:lipophile balance (HLB). Uptake of 2D-glucose and atrazine was enhanced at high humidity, the relative enhancement for atrazine increasing with increasing ethylene oxide (EO) content of the surfactants. A significant proportion of the atrazine and DDT entering the leaf was recovered from the epicuticular wax, the amount of atrazine recovered from the wax increasing with the EO content of the surfactants. The proportion of the surfactants taken up which was recovered from the epicuticular wax was minimal at an EO content of 12.5–16 mole equivalents. The appearance of the deposits on the leaf surface differed markedly among the surfactants, with similar trends for all three chemicals and without visible evidence for infiltration of the stomatal pores. The total quantities of glucose and atrazine translocated were increased by all surfactants but that of DDT was not, despite increases in uptake of up to 7.5-fold. Relative translocation (export from treated region of leaf as a percentage of chemical penetrating beyond the epicuticular wax) was reduced in all cases in the presence of surfactant. Up to 30% of the applied [14C]chemicals was not recovered from the treated leaf after 24 h. The reduced recovery of 2D-glucose, but not that of atrazine and DDT, was largely attributable to movement out of the treated leaf, with approximately 70% of the chemical taken up being translocated basipetally. Loss of atrazine and DDT was a result of volatilisation. There was no evidence that either [14C]2 D-glucose or [14C]atrazine was metabolised to [14C]carbon dioxide.  相似文献   

15.
The uptake and metabolism of DDT, fenitrothion and chlorpyrifos were studied in cultures of the ciliate protozoan Tetrahymena pyriformis. When cultures were treated with DDT in concentrations varying from 0.01 to 0.5 μg ml−1, concentrations found in T. pyriformis were 3.8 to 335 μg g−1 dry weight. The accumulation of fenitrothion ranged from 28.7 μg g−1 in cultures treated with 1 μg ml−1 to 2260 μg g−1 in cultures treated with 10 μg ml−1. Under similar experimental conditions chlorpyrifos was accumulated from 24.7 to 15400 μg g−1. The patterns of uptake were dependent on the growth cycle, the ability of the organism to metabolise insecticide and the type of the insecticide used. Maximum accumulation of DDT, fenitrothion and chlorpyrifos occurred in 2, 4 and 6 h respectively. Tetrahymena metabolised DDT to DDD and DDE but failed to metabolise fenitrothion and chlorpyrifos. The effects on growth and morphology of T. pyriformis were studied over a period of 5 days. Higher concentrations (10, 50 and 100 μg ml−1) of DDT inhibited only the growth of the organisms and did not change cell morphology. Fenitrothion was extremely toxic to the organisms and at 5 and 10 μg ml−1 cells became more or less spherical and died after 48 h. However, concentrations of 0.5, 1 and 2.5 μg ml−1 fenitrothion caused growth inhibition, but only at 2.5 μg ml−1 was this permanent. Chlorpyrifos inhibited the growth of the organisms at 1, 5 and 10 μg ml−1 but the morphology was affected only at 5 and 10 μg ml−1.  相似文献   

16.
When [14C]F3-fluorodifen (2,4′-dinitro-4-trifluoromethyl diphenylether), carbonyl-[14C]CDAA (N,N-diallyl-2-chloroacetamide), and carbonyl-14C-propachlor (2-chloro-N-isopropylacetanilide) were fed to rats, 57 to 86% of the 14C was excreted via the urine within 48 hr. Although very little radioactivity was excreted in the feces of CDAA-treated rats, 15–22% of the 14C was excreted in the feces of propachlor- of fluorodifentreated rats and an average of 8% of the 14C remained in these rats 48 hr after treatment. Oxidation of the 14C label to [14C]O2 was not a major process in the metabolism of these herbicides. The only major radioactive metabolite present in the 24-h urine of fluorodifen-treated rats, 2-nitro-4-trifluoromethylphenyl mercapturic acid, accounted for 41% of the administered dose of 14C. In the metabolism of CDAA, the corresponding mercapturic acid accounted for 76% of the dose; it was the only major metabolite present in the 24-h urine. In contrast, three major metabolites were detected in the 24-h urine of propachlortreated rats, and the mercapturic acid accounted for only 20% of the dose. The mercapturic acid of each herbicide was identified by mass spectrometry.  相似文献   

17.
Oligomycin-sensitive (O-S) Mg2+ ATPase from American cockroach muscle was more sensitive to DDT, TDE, methoxychlor, and DDE at cool temperatures than at warm temperature, thus showing a negative temperature effect. In contrast, inhibition by acaricides dicofol, chlorfenethol, and Plictran shows a positive temperature effect. Oxidative phosphorylation in a mitochondrial preparation from cockroach coxal muscle was reduced by DDT, but the reduction was greater at a higher temperature (32°C) than at a cooler temperature (22°C). In addition, Na+K+ ATPase from cockroach nerve cord showed a positive temperature effect with DDT. The inhibition by DDT was much less on Na+K+ ATPase than on O-S Mg2+ ATPase. The negative temperature effect by DDT and analogs on O-S Mg2+ ATPase parallels toxicity effects on insects and fish as reported by numerous researchers. The results provide further evidence for this energy-regulating enzyme being a critical component in the biological action of DDT.  相似文献   

18.
Chlorinated hydrocarbon pesticide burdens, especially those of DDT and its metabolites, have been determined for 19 species of small terrestrial migratory birds killed chiefly at Florida television towers from 1964 to 1973. All 128 samples were sorted into pools by species. All pooled samples except one contained DDE and often DDT and DDD; dieldrin was present in 60 of the samples; but no PCB's were detected. In small subsamples, sigma DDT (p,p'-DDT, p,p'-DDD, and p,p'-DDE) residues sometimes differed between males and females, adults and immatures, and northbound and southbound migrants but results of these comparisons were inconclusive. Sigma DDT burdens were highest in adipose tissue and much lower in liver and brain samples. Especially among birds taken since 1970 have the pesticide levels in adipose tissue been at low levels, generally less than 3 ppm sigma DDT. These low quantities are comparable to those quoted in other reports on birds of similar trophic levels. The insectivorous and/or partly granivorous birds feeding on or near the ground tended to have higher sigma DDT levels than did the more arboreal species.  相似文献   

19.
American cockroaches injected with sublethal doses of DDT (0.75 μg/roach) at 5-day intervals showed a 40% reduction in oligomycin-sensitive Mg2+ATPase from muscle homogenates, and a 23% reduction of Na+-K+ATPase from nerve cords. Thus, the maximum effect measured occurred with the same enzyme and tissue as determined from in vitro studies. The metabolite, DDE, used at 15 μg per roach, gave no significant change in activity of the ATPase system following injection. In contrast, high single doses of DDT (7.5 μg/roach) and 100 μg DDE and dicofol per roach caused over 30% increase in oligomycin-sensitive Mg2+ATPase of muscle and a 10–15% increase in Na+-K+ATPase of nerve cords measured 24 and 48 hr later. While a similar response was observed for Mg2+ATPase activities in cockroaches that were immobilized, the increase in enzyme activities were much greater than that caused by the pesticides.  相似文献   

20.
Glyphosate efficacy was examined in young velvetleaf plants from the standpoint of its tissue distribution and sensitivity. In whole plant assays, manual application of a sub-lethal dose to the first leaf resulted only in meristem injury while other tissues remained visually healthy. Our studies showed that this differential tissue response was caused by a combination of differential distribution as well as sensitivity to glyphosate. Using [14C]glyphosate, we measured tissue injury and glyphosate residue, and calculated tissue threshold for 50% growth inhibition. Our studies showed that roots and meristem have high glyphosate distribution (45 and 34% of translocated, respectively) and low inhibition thresholds (0.23 and 0.21 ppm, respectively) resulting in tissues that were easily killed by glyphosate. In contrast, the base stem contained a much higher inhibition threshold (8.4 ppm) with only intermediate distribution (10%) resulting in a tissue that was most difficult to kill. We observed a linear relationship between glyphosate dose and tissue concentration; furthermore, tissue distribution pattern was independent of dose or surfactants class. At a sub-lethal dose, sensitive tissues that received a large distribution of glyphosate were preferentially killed. As the dose was increased, more glyphosate was available for distribution, and all tissues received a proportionately greater amount of glyphosate. Plant death occurred when the applied dose was sufficient to attain the lethal threshold in all tissues.  相似文献   

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