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National Cancer Institute... 1978A bioassay of technical-grade azinphosmethyl for possible carcinogenicity was conducted by administering the test chemical in feed to Osborne-Mendel rats and B6C3F1...
A bioassay of technical-grade azinphosmethyl for possible carcinogenicity was conducted by administering the test chemical in feed to Osborne-Mendel rats and B6C3F1 mice. Groups of 50 rats of each sex were administered azinphosmethyl at one of two doses for 80 weeks, then observed for 34 or 35 weeks. Time-weighted average doses of either 78 or 156 ppm were used for the males. Initial doses of 62.5 or 125 ppm used for the females were maintained throughout the bioassay. Matched controls consisted of groups of 10 untreated rats of each sex; pooled controls consisted of the matched controls combined with 95 male and 95 female untreated rats from similar bioassays of 10 other test chemicals. All surviving rats were killed at 114 or 115 weeks. Groups of 50 mice of each sex were administered azinphosmethyl at one of two doses for 80 weeks, then observed for 12 or 13 weeks. The doses were either 31.3 or 62.5 ppm for the males and either 62.5 or 125 ppm for the females. Matched controls consisted of groups of 10 untreated mice of each sex; pooled controls consisted of the matched controls combined with 130 male and 120 female untreated mice from similar bioassays of 11 other test chemicals. All surviving mice were killed at 92 or 93 weeks. High- and low-dose male rats and mice and high-dose female rats and mice had lower mean body weights than corresponding matched controls throughout the bioassay. Typical signs of organophosphate intoxication were observed in a few animals of both species, and included hyperactivity, tremors, and dyspnea. Sufficient numbers of animals were at risk in each species for development of late-appearing tumors. A great many tumors of the endocrine organs were observed in both dosed male and dosed female rats. Those of the adrenal in dosed males and females, the follicular cells of the thyroid in dosed females, the anterior pituitary in dosed males, and the parathyroid in dosed males occurred at statistically significant incidences when compared with pooled controls, but not with matched controls, and they were not considered to be related to administration of the test compound. The incidences of tumors of the pancreatic islets and of the follicular cells of the thyroid in the male rats suggest, but do not clearly implicate, azinphosmethyl as a carcinogen in these animals. In mice of each sex there were no increased incidences of tumors that could be related to administration of the test chemical. It is concluded that under the conditions of this bioassay, neoplasms of the thyroid and pancreatic islets suggest but do not provide sufficient evidence for the carcinogenicity of azinphosmethyl in male Osborne-Mendel rats. Azinphosmethyl was not shown to be carcinogenic in female Osborne-Mendel rats or in B6C3F1 mice of either sex.
PubMed: 12830228
DOI: No ID Found -
Journal of Economic Entomology Jun 2000Resistance to several classes of insecticides was correlated with azinphosmethyl resistance in codling moth, Cydia pomonella (L.), in California. In tests of laboratory...
Resistance to several classes of insecticides was correlated with azinphosmethyl resistance in codling moth, Cydia pomonella (L.), in California. In tests of laboratory and field populations, cross-resistance was positively correlated with azinphosmethyl and two organophosphates (diazinon, phosmet), a carbamate (carbaryl), a chlorinated hydrocarbon (DDT), and two pyrethroids (esfenvalerate and fenpropathrin). Additionally, negatively correlated cross-resistance was identified between azinphosmethyl and two other organophosphates, chlorpyrifos and methyl parathion. Patterns of resistance observed in laboratory colonies were confirmed with field bioassays. In bioassays of field populations, azinphosmethyl resistance was observed to increase from 1991 to 1993, although levels of resistance remained < 13-fold. Because orchards with azinphosmethyl resistance have had difficulties with suppression of codling moth, and cross-resistance was found for all tested classes of insecticides, strategies for managing resistance will need to be developed so as to protect current and future control tactics. The two insecticides with negatively correlated cross-resistance are discussed as potential tools for resistance management.
Topics: Animals; Azinphosmethyl; Biological Assay; Female; Insect Control; Insecticide Resistance; Insecticides; Male; Moths
PubMed: 10902355
DOI: 10.1603/0022-0493-93.3.955 -
Archives of Environmental Health 1994We compared measurements of urinary alkylphosphate metabolites and oxime-induced reactivation of plasma cholinesterase (P-ChE) and erythrocyte acetylcholinesterase...
We compared measurements of urinary alkylphosphate metabolites and oxime-induced reactivation of plasma cholinesterase (P-ChE) and erythrocyte acetylcholinesterase (RBC-AChE) with measurements of foliar residues, skin and clothing contamination, and P-ChE and RBC-AChE activities among 20 Northern California peach orchard workers exposed to the organophosphate agent azinphosmethyl (Guthion). Subjects entered orchards treated 30 d previously with azinphosmethyl and worked 21 d in treated fields during the ensuing 6 wk. Dislodgeable foliar residues ranged from 0.32-0.96 micrograms/cm2. Median reduction in RBC-AChE activity was 7% (p < .001) over the initial 3-d period of exposure and 19% (p < .01) over the 6-wk season. Urinary metabolites were the most sensitive indicator of recent exposure and correlated moderately with dermal and clothing levels (rs = +0.31-(+)0.55); urinary metabolites correlated well with RBC-AChE drawn 3 d after exposure began (rs = -0.77). No significant oxime-induced reactivation was found.
Topics: Acetylcholinesterase; Adolescent; Adult; Agriculture; Azinphosmethyl; Cholinesterases; Clothing; Cross-Sectional Studies; Erythrocytes; Fruit; Humans; Male; Middle Aged; Occupational Exposure; Organophosphorus Compounds; Skin
PubMed: 8031187
DOI: 10.1080/00039896.1994.9937482 -
Environmental Health Perspectives Jun 1994Peach harvest workers were evaluated for exposure to azinphosmethyl residues by measuring foliar residues, urinary alkylphosphate metabolites, butyrylcholinesterase...
Peach harvest workers were evaluated for exposure to azinphosmethyl residues by measuring foliar residues, urinary alkylphosphate metabolites, butyrylcholinesterase (BChE), acetylcholinesterase (AChE), and dermal residues using clothing and skin washes. Workers entered orchards 51 days after application and worked in treated fields for 10 of the next 17 days. Dislodgeable foliar residues ranged from 0.82 to 1.72 microg/cm2 and did not change significantly over the study period. Combined mean dermal exposure for the 3 consecutive monitoring days was 32 mg and ranged from 17.9 to 60.5 mg. Overall mean excretion levels for the 5 monitoring days were 1.7 mg dimethylphosphate and 1.9 mg dimethlythiophosphate. There was no significant difference in BChE between the exposed harvesters and minimally exposed sorters. The exposed group had significantly lower AChE values than the sorters for 2 post-exposure blood draws by three testing methods, while no significant difference was found for the pre-exposure blood draw. The AChE values for the post-exposure blood samples for the exposed workers decreased significantly about 10-20% over the 3-week exposure period but increased or remained constant for the sorters. Urinary metabolite excretion increased with continuous exposure and was inversely correlated with both AChE and BChE but was not correlated with dermal exposure measurements. High correlations were generally observed between AChE measurements taken in the field using a new spectrophotometric kit and laboratory AChE measurements.
PubMed: 9679119
DOI: 10.1289/ehp.94102580 -
Environmental Toxicology and Chemistry Oct 2008The organophosphorous compound azinphosmethyl (AzMe) is applied extensively in northern Patagonia (southern Argentina) to manage codling moths (Cydia pomonella). This...
The organophosphorous compound azinphosmethyl (AzMe) is applied extensively in northern Patagonia (southern Argentina) to manage codling moths (Cydia pomonella). This area is irrigated by fast-flowing channels that provide a favorable habitat for many species, including amphipods (Hyalella curvispina) and a field-mixed population of black flies (Simulium bonaerense, Simulium wolffhuegeli, and Simulium nigristrigatum). In the present study, AzMe susceptibility and carboxylesterase (CarbE) activity from both insecticide-exposed and nonexposed field populations were studied. The median lethal dose determined in codling moths from an insecticide-treated orchard was significantly higher (3.48 microg/insect) than that observed in those from an untreated orchard (0.69 microg/insect). Similarly, the median lethal concentration (LC50) determined in black flies collected from the treated area (0.021 mg/L) was significantly higher than that recorded in those from the untreated site (0.011 mg/L). For amphipods, both a subpopulation susceptible to AzMe (LC50, 1.83 microg/L) and a resistant one (LC50, 390 microg/L) were found in the treated area. Both subpopulations were more resistant to AzMe than the population from the untreated site (LC50, 0.43 microg/L). Significant differences (p < 0.001) in CarbE activities were observed between populations from pesticide-treated and untreated areas. Mean activities +/- standard deviation from treated and untreated sites were 0.21 +/- 0.16 and 0.016 +/- 0.008 micromol/min/mg protein, respectively, for codling moths; 2.17 +/- 1.71 and 0.81 +/- 0.35 micromol/min/mg protein, respectively, for black flies; and 0.27 +/- 0.10 and 0.14 +/- 0.07 micromol/min/mg protein, respectively, for amphipods. The results suggest that enhanced CarbE activity is one of the mechanisms that provide AzMe resistance in H. curvispina, Simulium spp., and C. pomonella populations from the insecticide-treated areas.
Topics: Amphipoda; Animals; Azinphosmethyl; Carboxylic Ester Hydrolases; Cholinesterase Inhibitors; Diptera; Drug Resistance; Esterases; Insecticides; Invertebrates; Larva; Lethal Dose 50; Moths
PubMed: 18386945
DOI: 10.1897/07-655.1 -
American Journal of Veterinary Research Aug 1974
Topics: Administration, Oral; Animal Feed; Animals; Azinphosmethyl; Cholinesterases; Erythrocytes; Horse Diseases; Horses; Insecticides; Medicago sativa; Time Factors
PubMed: 4853484
DOI: No ID Found -
Comparative Biochemistry and... Dec 2000This study aims to investigate the effects of the herbicide 2,4-D and the insecticide azinphosmethyl on hepatic antioxidant enzyme activities and lipid peroxidation in...
This study aims to investigate the effects of the herbicide 2,4-D and the insecticide azinphosmethyl on hepatic antioxidant enzyme activities and lipid peroxidation in tilapia. Fish were exposed to 27 ppm 2,4-D, 0.03 ppm azinphosmethyl and to a mixture of both for 24, 48, 72 and 96 h. Activities of catalase (EC 1.11.1.6), glutathione-S-transferase (GST, EC 2.5.1.18) and the level of malondialdehyde (MDA) in the liver of Oreochromis niloticus exposed to 2,4-D and azinphosmethyl, both individually and in combination, were not affected by the pesticide exposures. However, glucose-6-phosphate dehydrogenase (G6PD, EC 1.1.1.49) and glutathione reductase (GR, EC 1.6.4.2) activities in individual and combined treatments, increased significantly compared to controls. Furthermore, glutathione peroxidase (GPx, EC 1.11.1.9) activity increased in individual treatment, while the same enzyme activity decreased in combination. 2,4-D did not affect the activity of superoxide dismutase (SOD, EC 1.15.1.1), but the activity of this enzyme in azinphosmethyl treatment decreased, while its activity increased in combination. Combined treatment of the pesticides exerted synergistic effects in the activity of SOD, while antagonistic effects were found in the activities of G6PD, GPx, GR. The results indicate that O. niloticus resisted oxidative stress by antioxidant mechanisms and prevented increases in lipid peroxidation.
Topics: 2,4-Dichlorophenoxyacetic Acid; Animals; Antioxidants; Azinphosmethyl; Catalase; Enzymes; Glucosephosphate Dehydrogenase; Glutathione Peroxidase; Glutathione Reductase; Herbicides; Insecticides; Lipid Peroxidation; Liver; Male; Superoxide Dismutase; Tilapia
PubMed: 11246500
DOI: 10.1016/s0742-8413(00)00159-6 -
Pesticide Biochemistry and Physiology Jun 1996Azinphosmethyl-selected tufted apple bud moths were compared to susceptible and reverted strains with respect to possible metabolic mechanisms of resistance within the...
Azinphosmethyl-selected tufted apple bud moths were compared to susceptible and reverted strains with respect to possible metabolic mechanisms of resistance within the third instar, fifth instar, and adults. Based upon bioassays conducted by topical application with azinphosmethyl, LD50s were as high as 867-fold in the selected strain as compared to that seen in susceptible bud moths. The LD50 of the reverted strain was intermediate to that of the susceptible and selected insects at all stages studied. Glutathione transferase activity measured with 1-chloro-2,4-dinitrobenzene was elevated in the selected strain 1.6- and 2.2-fold as compared to third and fifth stadium susceptible bud moths, respectively. No consistent strain differences were noted for 1,2-dichloro-4-nitrobenzene. Cytochrome P450 content and P450 mRNA was not significantly different in fifth instars of the susceptible and selected strain. However, there was a 2.7- and 1.9-fold increase in benzphetamine and p-nitroanisole metabolism, respectively, in the guts of azinphosmethyl-selected fifth instars. Benzo[a]pyrene metabolism was elevated 2.4-fold in the carcass of selected bud moths and no differences were noted for methoxyresorufrin in either gut or carcass. Susceptible fifth instars demonstrated a reduced rate of metabolism of azinphosmethyl to the oxon and methyl benzazamide. Piperonyl butoxide failed to synergize azinphosmethyl toxicity. Esterase activity measured with 1-naphthyl acetate and p-nitrophenyl acetate was elevated in selected larvae compared to that seen in susceptible tufted apple bud moths in both larvae and adults. This increased esterase activity was attributed to several isoforms as resolved by analytical isoelectric focusing. One of these forms was consistently overexpressed in all of the life stages examined. Pretreatment of selected fifth instars with S,S,S-tributylphosphorotrithioate increased the toxicity of azinphosmethyl 400-fold and had minimal effect on toxicity in susceptible insects. It appears that multiple hydrolases are the primary metabolic factor in azinphosmethyl resistance in the tufted apple bud moth.
PubMed: 8980035
DOI: 10.1006/pest.1996.0040 -
Aquatic Toxicology (Amsterdam,... Oct 2007Assessment of cholinesterase (ChE) inhibition is widely used as a specific biomarker for evaluating the exposure and effects of non-target organisms to...
Assessment of cholinesterase (ChE) inhibition is widely used as a specific biomarker for evaluating the exposure and effects of non-target organisms to anticholinesterase agents. Cholinesterase and carboxylesterase activities have been measured in larvae of gilthead seabream, Sparus aurata, during the endogenous feeding stage, and ChE was characterized with the aid of diagnostic substrates and inhibitors. The results of the present study showed that whole-body ChE of yolk-sac seabream larvae possesses typical properties of acetylcholinesterase (AChE) with a apparent affinity constant (K(m)) of 0.163+/-0.008 mM and a maximum velocity (V(max)) of 332.7+/-2.8 nmol/min/mg protein. Moreover, sensibility of this enzyme was investigated using the organophosphorus insecticide azinphosmethyl. Static-renewal toxicity tests were conducted over 72 h and larval survival and AChE inhibition were recorded. Mean mortality of seabream larvae increased with increasing concentrations of azinphosmethyl and exposure duration. The estimated 72-h LC50 value to azinphosmethyl was 4.59 microg/l (95% CI=0.46-8.71 microg/l) and inhibition of ChE activity gave an IC50 of 3.04 microg/l (95% CI=2.73-3.31 microg/l). Larvae exposed to azinphosmethyl for 72h showed a 70% inhibition of the whole-body acetylcholinesterase activity at approximately the LC50. In conclusion, the results of the present study suggested that monitoring ChE activity is a valuable tool indicating OP exposure in S. aurata larvae and that acetylthiocholine is the most appropriate substrate for assessing ChE inhibition in this early-life stage of the fish.
Topics: Animals; Azinphosmethyl; Benzenaminium, 4,4'-(3-oxo-1,5-pentanediyl)bis(N,N-dimethyl-N-2-propenyl-), Dibromide; Cholinesterase Inhibitors; Cholinesterases; Inhibitory Concentration 50; Insecticides; Kinetics; Larva; Physostigmine; Sea Bream; Substrate Specificity; Tetraisopropylpyrophosphamide; Yolk Sac
PubMed: 17688956
DOI: 10.1016/j.aquatox.2007.06.009 -
Spectrochimica Acta. Part A, Molecular... Aug 2019Development of simple and rapid methods for identification of pesticides, due to their broad usage and harmful effects on mammals, has been known as a critical demand....
Development of simple and rapid methods for identification of pesticides, due to their broad usage and harmful effects on mammals, has been known as a critical demand. Herein, we have introduced a silver nanoparticle (AgNP) based colorimetric sensor array for simultaneous identification of Azinphosmethyl (AM) and Phosalone (PS) pesticides. In the presence of the target pesticides, unmodified AgNPs at various pHs (4.5, 5.5 and 9.5) showed different aggregation behaviors. As a result of aggregation, the color and UV-Vis spectra of AgNPs changed differentially, leading to distinct response patterns for AM and PS. The aggregation induced spectral changes of AgNPs, were used to identify AM and PS with the help of linear discriminant analysis (LDA). The applicability of the proposed sensor array was then evaluated by identifying the target pesticides in apple samples. Altogether, the developed AgNPs based colorimetric sensor array can be potentially exploited as an efficient discrimination tool in the near future for agrichemical applications.
Topics: Azinphosmethyl; Colorimetry; Food Contamination; Hydrogen-Ion Concentration; Malus; Metal Nanoparticles; Organothiophosphorus Compounds; Pesticides; Silver
PubMed: 31077953
DOI: 10.1016/j.saa.2019.04.074