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At least 37 records · Page 2Linked to original sources
PubMed1985

Effect of selection for dichlorodiphenyltrichloroethane (DDT) resistance on the uptake and breakdown of DDT in Aedes aegypti L.

Aedes aegypti larvae and adults were selected to high levels of resistance with dichlorodiphenyltrichloroethane (DDT) along separate lines. The larval-selected line showed three responses associated with larval resistance: increased detoxication of DDT by dehydrochlorination to dichlorodiphenyldichloroethane DDE (demonstrated both in vivo and in vitro), increased tolerance to unmetabolised ("residual") DDT and, a reduction in uptake of DDT. Larval selection caused very little change in adult resistance or the uptake of DDT by adults, but there was an increase in dehydrochlorination. In the adult-selected line dehydrochlorination was increased by selection and was significantly correlated with resistance.

Aedes↗
PubMed1970

Effects of temperature on the irritability caused by DDT and DDT-analogues in anopheline mosquitos.

The author reports a series of investigations into the effects of temperature on irritability, caused by DDT or its analogues methoxychlor and DDD, in Anopheles labranchiae atroparvus and An. gambiae, species B; into the irritability of three other anophelines upon exposure to deposits of water-dispersible DDT powder; and into the relation between aging and DDT-irritation in anophelines. Irritability was measured by both the number of take-offs and the duration of flight over a 20-minute period at temperatures of from 19 degrees C to 32 degrees C.The flight activity of An. 1. atroparvus and An. gambiae B increased with increasing temperature to a peak at 23 degrees C for the former and 27 degrees C for the latter; it then fell with further increase in temperature to 32 degrees C.Over 20 minutes, the DDT-resistant An. pharoensis was less irritated than either An. gambiae A or An. punctulatus farauti (both susceptible) but over 30 minutes was more so than An. p. farauti.Among other findings were that methoxychlor and DDD were stronger irritants than DDT and that irritability declined with increasing age of the mosquitos.

Age Factors↗
PubMed1978

DDT residues in rainwater in New Brunswick and estimate of aerial transport of DDT into the Gulf of St. Lawrence, 1967-68.

Residues of DDT were detected in 76 of 101 samples of rainwater collected during spring and summer at several sites in the Province of New Brunswick in 1967 and 1968, and at one site in the Magdalen Islands, Quebec, in 1968. The dominant residue was p,p'-DDT. Levels of DDT and metabolites combined ranged from less than 0.01 to 1.33 microgram/kg. Levels of DDT and metabolites in the pollen of four species of forest trees in New Brunswick ranged from 0.544 to 1.01 mg/kg; such contaminated pollen possibly contributed to residues in rainwater. Residue data for rainwater from two sites were used to estimate the amount of DDT aerially transported into the Gulf of St. Lawrence during July to October 1968.

Chromatography, Gas↗
PubMed1985

[The enzymatic degradation of DDT. 3. Metabolism of DDT].

DDT orally given to rats is converted into DDD by reductive dechlorination in the liver within 30 min. 6 h after a single application of 10 mg DDT per rat a quantity of 60 mg DDD/kg was indicated in the liver. DDT is stored in the adrenal glands; in the other organs an equilibrium comes up obviously, even with further application. The quantitative ratios are reported. Information on the experimental details of DDT determination and--anticipatory to the following publications--on the analysis of the most relevant metabolites is given.

Animals↗
PubMed1984

The estrogenic activity of DDT: the in vitro induction of an estrogen-inducible protein by o,p'-DDT.

Induced protein is a commonly measured marker for estrogenic action. The induction of induced protein by o,p'-DDT was studied in an in vitro system. Nuclear levels of estrogen receptor translocated by o,p'-DDT correlated highly with induced protein induction, and the time course for induced protein induction was consistent with an estrogen receptor-mediated mechanism. While the maximum amount of induced protein produced by o,p'-DDT was less than after 17 beta-estradiol exposure, the induced protein formed by each compound was indistinguishable on nondenaturing and denaturing polyacrylamide gels. Also, it was shown that o,p'-DDT does not cause additional induction of induced protein over that seen with maximum levels of 17 beta-estradiol, further supporting the premise that these compounds share a common pathway in stimulating the synthesis of induced protein.

Animals↗
PubMed2004

Catalytic hydrotreating of 2,4'-DDT and 4,4'-DDT.

The results of catalytic hydrotreating of a commercial mixture of 2,4'-DDT and 4,4'-DDT are reported. Experimental runs were carried out in a batch reactor (300 cm3) at constant hydrogen pressure (PH2 = 20 bar) and temperature. Temperature levels 150, 180, 200 and 230 degrees C were tested. A commercial sulphide Ni-Mo catalyst was adopted. The reacting medium was hexadecane. The kinetic constant and reaction order of the destruction reaction of 2,4'-DDT and 4,4'-DDT have been evaluated at temperature of 180, 200 and 230 degrees C. Destruction and removal efficiency (DRE) at T = 230 degrees C has been calculated.

Catalysis↗
PubMed1985

Effects of p,p'-DDT on the rat brain concentrations of biogenic amine and amino acid neurotransmitters and their association with p,p'-DDT-induced tremor and hyperthermia.

Male, Fischer strain 344 adult rats were given various doses (25-100 mg/kg) of p,p'-DDT by oral gavage, and levels of biogenic amines, their metabolites, and amino acid neurotransmitters, tremor activity, and rectal temperature were measured at several intervals (2, 5, 12, and 24 h) after dosing. Dose-related increases in rectal temperature and in tremor activity were observed at 50-100 mg/kg 12 h after dosing. Tremorigenic doses of DDT increased the 5-hydroxyindoleacetic acid (5-HIAA) level in hypothalamus, brainstem, and striatum, whereas doses of 75 and 100 mg/kg increased the 3-methoxy-4-hydroxyphenylglycol (MHPG) level in hypothalamus and brainstem and the 3,4-dihydroxyphenylacetic acid level in striatum. Six amino acids were assayed in the brainstem, hypothalamus, and striatum; aspartate and glutamate levels were increased only in brainstem at 25-100 mg/kg. No consistent changes in concentrations of taurine, glutamine, glycine, or gamma-aminobutyric acid were observed in any of the regions assayed. Time-related increases in rectal temperature were seen 2-12 h after dosing, and the presence of tremor was observed 5-12 h after dosing; for both the time of peak effect was at 12 h. The DDT-induced hyperthermia and tremor were associated with dose- and time-related increases in levels of 5-HIAA, MHPG, aspartate, and glutamate. It is suggested that an increase in the turnover rate of 5-hydroxytryptamine (5-HT) may be responsible for the DDT-induced hyperthermia, whereas increases in the metabolism of 5-HT and norepinephrine may be involved in the tremor.

Amino Acids↗
PubMed1981

DDT-resistant Culex quinquefasciatus: the effect of DDT on the mosquito's size, fecundity and survival.

Resistant strains of Culex quinquefasciatus were selected in the larval stage by exposure to sublethal doses of DDT. The size, body weight and fecundity of DDT-resistant mosquitoes were significantly decreased. There was no significant difference between the longevity of females in the original strain and the DDT selected strains, however, there was a significant difference in the males of the DDT-resistant strains than those of the original strain.

Animals↗
PubMed1983

[Residue status of DDT, lindane and metabolites in grain after separation from DDT preparations].

The use of insecticides in grain-production plays a minor role in the GDR. Nevertheless grain samples have been tested for DDT, DDE and Lindane residues since 1971 and in addition to this for alpha-, beta-, and delta-HCH as well as for HCB in the last years. These residues are to be traced back to unintentional contamination due to absorption from the soil or to leeway. The grain samples were tested for the residues by GC analysis. From 1971 to 1980 the contamination of grain with DDT and Lindane residues decreased. The alpha-, beta-, and delta-HCH residues as well as those of HCB were found between 0.5 microgram/kg and 5 micrograms/kg. The residues of DDT and HCH were below 0,02 mg/kg, the negligible amounts ("zero tolerance") for these substances fixed in the GDR order on pesticides in foods, or below 0,05 mg/kg in case of HCB, being the tolerance (maximum allowable amount) for this substance.

DDT↗
PubMed1975

Dieldrin and DDT in the tissues of mice fed aldrin and DDT for seven generations.

Seven-Generation Study (P-F6): The concentration and total retention of dieldrin or p,p'-DDT and metabolites were determined in the total carcass of Swiss-Webster mice fed dietary supplements of aldrin 5 or 10 ppm, or DDT 100 ppm, to age 260 days. All groups showed a significant increase in total body retention (and concentration) of dieldrin or total DDT in the total carcass of the F1, F2, and F3 generations. Generally, these increases were related directly to increases in total body lipids, when compared with the P generations. The control (pesticide-free) diet was fed to all F4 generation experimental mice from weaning to age 260. The pesticides absorbed by these animals while in utero and via lactation were found, at the time of sacrifice, to have been excreted completely. When the experimental diets were resumed with the weanlings of the F2 generations, a repetition of the general findings in the P and F1 generations was noted-demonstrating that pesticide retention and total body lipids are closely interrelated, and that a high body lipid content favors a high retention rate of these fat-soluble pesticides. These results support our earlier studies in rats (Deichmann et al., 1972) and investigations with cirrhotic human livers with severe fatty infiltration (Oloffs et al., 1974). Conception became more delayed with each succeeding generation, requiring some degree of "selective" breeding of the F4, F5, and F6 generations.

Adipose Tissue↗
PubMed1976

DDT: the degradation of ring-labeled 14C-DDT to 14CO2 in the rat.

Ring fission of p, p'-DDT was studied in the rat following a single oral dose of 0.74 mg/kg (1.04 muCi) of uniformly ring-labeled 14C-DDT. Expired air was passed through a solution of ethanolamine-ethylene glycol monomethyl ether (1:2) to trap 14CO2. A total of 1.6% of the radioactivity administered was recovered in the expired air collected continually for 10 days, indicating that while degradation of the phenyl moiety is not a major route of p,p'-DDT metabolism in the rat, it is equal to the urinary excretion. Nevertheless, these results represent the most radical change accomplished in vivo of a residual insecticide yet reported in mammals.

Animals↗
PubMedDate not supplied

Gas chromatographic method for determination of p,p'-DDT in DDT technical and formulated products: collaborative study.

A gas chromatographic (GC) method for determination of p,p'-DDT in technical and formulated products was developed and it performed well in an initial small collaborative study among 4 laboratories. Samples are dissolved in chloroform, and p,p'-DDT is separated on an OV-210 column and determined by GC analysis with flame ionization detection. 2,2'-Dinitrobiphenyl is used as an internal standard. The method was subjected to an international collaborative study with 10 participating laboratories. Collaborators received matched pairs of technical DDT products and of water-dispersible powder, emulsifiable concentrate, and dustable powder formulations. Relative standard deviations for reproducibility (RSDR) for the paired samples were 1.16, 1.48, 2.08, and 1.80%, respectively. The method has been approved interim official first action by AOAC as a CIPAC-AOAC method.

Chromatography, Gas↗
PubMed1980

Influence of a local source of DDT pollution on statewide DDT residues in waterfowl wings, northern Alabama, 1978-79.

Heavy DDT contamination resulting from a former DDT manufacturing plant in northern Alabama has influenced statewide averages of DDT, DDE, and TDE residues in duck wings tested in the National Pesticide Monitoring Program. In states where contaminant levels in duck wings are high, residue analyses of wings categorized by finer geographic subdivision may be useful in defining the areas of heaviest contamination.

Alabama↗
PubMed1978

Residues of polychlorinated biphenyls, DDT, and DDT metabolites in Pennsylvania streams, community water supplies, and reservoirs, 1974--76.

Pennsylvania streams, community water supplies, and open water reservoirs were analyzed for PCB mixtures, DDT, and DDT metabolites. Streams were sampled in 1974 and again in 1975. Only 4 of 19 stream locations were contaminated. Maximum concentrations in community supplies of Aroclor 1242 (2 locations), Aroclor 1254 (3 locations), and sigmaDDT (2 locations) were 350, 260, and 620 ng/kg, respectively. Of the 110 community water supplies sampled in 1975 and 1976, only 7 contained residues. Maximum concentrations in community supplies of Aroclor 1242 (4 locations) and sigmaDDT (2 locations) were 460 ng/kg and 75 ng/kg, respectively. The seventh contained 0.7 ng/kg of dieldrin. None of the three open water reservoirs contained detectable residues of the compounds of interest. Essentially no correlation was found between PCB and DDT analogs in streams and those in fish from streams which had been samples at similar locations in a related study in 1976.

Chromatography, Gas↗
PubMed1953

Daytime distribution of DDT-resistant houseflies inside DDT-sprayed buildings.

The development of DDT resistance in houseflies makes necessary the use of an additional or substitute insecticide in fly control. For the sake of economy, and to prevent the rapid production of new resistant strains, spraying of this insecticide should be restricted as far as possible to those surfaces known to be the most frequented by flies.Between July and October 1952, an investigation into the day-time distribution and resting habits of flies inside a number of different buildings sprayed bi-monthly with 5% DDT in kerosene was carried out by the author. The results showed that walls and ceilings were the least frequented, windows and doors highly frequented, and furniture the most frequented. These data indicate the desirability of developing an insecticidal preparation adaptable to the residual treatment of furniture, and, in the absence of such a preparation, of restricting treatment to doors and windows and such night-time resting-places as are to be found inside rooms.

Animals↗
PubMed1976

[Comparative effects of intravitellin injections of p, p'-DDT and of commercial DDT on the germ cells of embryonic gonads of birds].

The p, p'-DDT present in the composition of commercial DDT, is responsible for the germ deficit in the gonads of bird embryos. Administered into the vitellus or on the shell, before incubation, the pesticide exerts the same reduction of the Quail germ population. While, for the Chick, the germ decrease is less significant after injection than after immersion.

Animals↗