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Ecotoxicology and Environmental Safety Mar 2004Laboratory toxicity data contrasting mortality and brain cholinesterase inhibition in the goldfish (Carassius auratus) are presented. Brain cholinesterase (ChE) was...
Time course of brain cholinesterase inhibition and recovery following acute and subacute azinphosmethyl, parathion and carbaryl exposure in the goldfish (Carassius auratus).
Laboratory toxicity data contrasting mortality and brain cholinesterase inhibition in the goldfish (Carassius auratus) are presented. Brain cholinesterase (ChE) was greatly reduced after 96 h of exposure in vivo at sublethal concentrations of azinphosmethyl and parathion. The inhibition of the enzyme was dose dependent, and concentrations higher than 0.1mg/L caused more than 90% inhibition. The effect of carbaryl was less pronounced, achieving an 86% inhibition at concentrations corresponding to the 96-h LC50. After in vivo exposure to sublethal concentrations of parathion and azinphosmethyl (0.1 mg/L) and carbaryl (3.0 mg/L), the activity of the goldfish brain ChE was greatly reduced. In the following 96 h of recovery, the enzyme inhibited with carbaryl was restored to 75% activity, while the enzyme inhibited with organophosphates (OPs) required more than 35 days for recovery. Goldfish were able to withstand high percentages of brain ChE inhibition without mortality, suggesting that another target may be responsible for the lethal effects. However, the enzyme is a good biomarker of acute and subacute exposure to OPs and carbamates.
Topics: Acetylcholinesterase; Animals; Azinphosmethyl; Biomarkers; Brain; Carbaryl; Cholinesterase Inhibitors; Dose-Response Relationship, Drug; Goldfish; Parathion
PubMed: 15041264
DOI: 10.1016/S0147-6513(02)00069-6 -
Journal of Applied Toxicology : JAT Jan 2019Organophosphorus compounds (OPCs), inhibitors of acetylcholinesterase (AChE), are useful agents as pesticides, but also represent a serious health hazard. Standard... (Review)
Review
Organophosphorus compounds (OPCs), inhibitors of acetylcholinesterase (AChE), are useful agents as pesticides, but also represent a serious health hazard. Standard therapy with atropine and established oxime-type enzyme reactivators (pralidoxime, obidoxime) is unsatisfactory. Better therapeutic results are obtained, when reversible AChE inhibitors are administered before OPC exposure. This review summarizes the history of such a pretreatment approach and sums up a set of experiments undertaken in search of compounds that are efficacious when given before a broad range of OPCs. The prophylactic efficacy of 10 known AChE inhibitors, either already used clinically for different indications (physostigmine, pyridostigmine, ranitidine, tiapride, tacrine, amiloride, metoclopramide, methylene blue) or developed for possible therapeutic use in the future (7-methoxytacrine, K-27) was compared, when administered before exposure to six chemically diverse OPCs in the same experimental setting: ethyl-paraoxon, methyl-paraoxon, diisopropylfluorophosphate, terbufos sulfone, azinphos-methyl and dicrotophos. The experimental oxime K-27 was the most efficacious compound, affording best protection, when administered before terbufos sulfone, azinphos-methyl and dicrotophos, second best before ethyl- and methyl-paraoxon exposure and third best before diisopropylfluorophosphate administration. This ranking was similar to that of physostigmine, which was superior to the Food and Drug Administration-approved pretreatment for soman with pyridostigmine. Tiapride, amiloride, metoclopramide, methylene blue and 7-methoxytacrine did not achieve protection. No correlation was observed between the IC of the reversible AChE inhibitors and their protective efficacy. These studies indicate that K-27 can be considered a very promising broad-spectrum prophylactic agent in case of imminent organophosphate exposure, which may be related to its AChE reactivating activity rather than its AChE inhibition.
Topics: Animals; Cholinesterase Inhibitors; Humans; Models, Animal; Organophosphate Poisoning; Organophosphates; Pre-Exposure Prophylaxis
PubMed: 30027640
DOI: 10.1002/jat.3662 -
Toxicology and Applied Pharmacology Jul 1976
Comparative Study
Topics: Administration, Oral; Administration, Topical; Animals; Azinphosmethyl; Cholinesterase Inhibitors; Female; Insecticides; Lethal Dose 50; Male; Organothiophosphorus Compounds; Parathion; Rats; Time Factors
PubMed: 968909
DOI: 10.1016/s0041-008x(76)80010-5 -
Environmental Toxicology and Chemistry Jul 2010We conducted dose-response exposures to compare the lethality of endosulfan, diazinon, and azinphosmethyl in the early-life stages of the Great Basin spadefoot (Spea...
Effects of environmentally relevant concentrations of endosulfan, azinphosmethyl, and diazinon on Great Basin spadefoot (Spea intermontana) and Pacific treefrog (Pseudacris regilla).
We conducted dose-response exposures to compare the lethality of endosulfan, diazinon, and azinphosmethyl in the early-life stages of the Great Basin spadefoot (Spea intermontana) and the Pacific treefrog (Pseudacris regilla). Our experiment occurred in two 8-d phases: one, with developing embryos, and two, with Gosner Stage 27 tadpoles. Pesticide concentrations were representative of field-measured concentrations (60 ng/L of endosulfan, 50 ng/L of azinphosmethyl, and 350 ng/L of diazinon), in the same geographic areas where these species occur in British Columbia. Although the concentrations met the requirements for federal water quality guidelines, we observed mortalities, deformities, and other sublethal effects. Phase 1 consisted of exposing Gosner Stage 10 embryos in the pesticide solutions for a total of 8 d. Significant mortality of S. intermontana began posthatch in the highest lethal concentrations of the commercial formulations of endosulfan (Thiodan; LC20(8d)=2,672.7 ng/L) and diazinon (LC20(8d)>175,000 ng/L). Phase 2 compared behavior, morphology, and survival of captive-reared tadpoles exposed to the same 8-d experimental regime as the embryo experiment. Endosulfan induced significant effects on behavior and morphology of P. regilla and significantly reduced survivorship of S. intermontana (LC20(8d)=77.1 ng/L). Abnormal behavior and excitability was observed in both species, with P. regilla tadpoles being more sensitive. At 60,000 ng/L endosulfan, P. regilla also lost pigmentation and exhibited abnormal tail morphology.
Topics: Animals; Anura; Azinphosmethyl; Diazinon; Dose-Response Relationship, Drug; Endosulfan; Environmental Pollutants; Larva; Pesticides
PubMed: 20821611
DOI: 10.1002/etc.203 -
Journal of Biochemical and Molecular... 2002The potential utility of antioxidant enzymes and lipid peroxidation as indicators of exposure to 2,4-D and azinphosmethyl together with the toxic effects of these...
The potential utility of antioxidant enzymes and lipid peroxidation as indicators of exposure to 2,4-D and azinphosmethyl together with the toxic effects of these compounds in freshwater fish Cyprinus carpio were evaluated. Biochemical parameters were recorded spectrophotometrically in fish liver, which were exposed to a single dose of 2,4-D and azinphosmehtyl (1/3 LC(50)), and their mixture at 1:1 ratio for 24, 48, 72, and 96 h. The most sensitive parameter was glutathione S-transferase (GST) activity, which significantly increased with experimental exposures. Glucose 6-phosphate dehydrogenase activity did not change after 24 and 48 h while there was an elevation after 72 h in all exposure groups. The activity decreased only when these were applied in combination at 96 h. Superoxide dismutase activity increased after azinphosmethyl exposure for 48 and 96 h. 2,4-D decreased the activity after 24 h while the activity remained at the same level with control after 48 h. An elevation was found between 72 and 96 h. Mixture treatment did not changed the activity. Glutathione reductase and catalase enzyme activities, and malondialdehyde levels remained constant in all the treatment groups compared with controls. These results suggest that induction of GST activity may be used as biomarker for the assessment of water pollution in C. carpio.
Topics: 2,4-Dichlorophenoxyacetic Acid; Animals; Azinphosmethyl; Carps; Catalase; Glucosephosphate Dehydrogenase; Glutathione Peroxidase; Glutathione Reductase; Glutathione Transferase; Lipid Peroxidation; Liver; Malondialdehyde; NADP; Superoxide Dismutase; Thiobarbituric Acid Reactive Substances
PubMed: 12242687
DOI: 10.1002/jbt.10040 -
Spectrochimica Acta. Part A, Molecular... Dec 2019
Corrigendum to "ThThnated Development of a pH assisted AgNP-based Colorimetric Sensor Array for Simultaneous Identification of Phosalone and Azinphosmethyl Pesticides" [Spectrochim. Acta A Mol. Biomol. Spectrosc. 219 (2019) 496-503].
PubMed: 31160184
DOI: 10.1016/j.saa.2019.117155 -
Environmental Toxicology and Chemistry Oct 2002We evaluated the potential effects of the organophosphate insecticide azinphosmethyl (AZP) in a combined microcosm and field approach. The upper regions of the Lourens...
We evaluated the potential effects of the organophosphate insecticide azinphosmethyl (AZP) in a combined microcosm and field approach. The upper regions of the Lourens River, South Africa, are free of contamination (control site), whereas the subsequent stretches flowing through a 400-ha orchard area receive transient insecticide pollution (e.g.. 0.82 microg/L AZP, 344 microg/kg chlorpyrifos) following spray drift and runoff (contaminated site). Stones taken from the control site were transferred to outdoor microcosms (1.5 x 0.2 x 0.2 m), providing 12 core species and approximately 350 individuals per microcosm. Microcosms were contaminated for 1 h with AZP (control, 0.2, 1, 5, and 20 microg/L; three replicates each), and acute effects on survival were evaluated 6 d following exposure. The two strongest treatments (measured concentrations: 19.2 +/- 1.0 and 4.9 +/- 0.3 microg/L, respectively) resulted in a significantly (analysis of variance) reduced invertebrate density, attributed mainly to various insect taxa, such as Demoreptus sp., Castanophlebia sp., Simuliidae, and Chironomidae. In contrast, Aeshna sp., Dugesia sp., Ceratopogonidae, and Cheumatopsyche sp. were unaffected. In parallel, we conducted a quantitative macroinvertebrate survey at the control site and the contaminated site of the Lourens River after the seasonal pesticide application period. The two sites contained a similar number of species but differed considerably in their species composition and abundances. Five of the eight species that were affected by AZP in the microcosm study occurred in the field at significantly lower densities at the contaminated than at the control site or were absent at the contaminated site. All of the four species that were unaffected in the microcosm occurred at significantly higher densities at the contaminated field site. Only 3 of the 12 species reacted differently in the microcosm and the field study. We conclude that microcosm studies employing a field-relevant design could be linked successfully to field studies and our results suggest that transient pesticide contamination affects the aquatic communities of the Lourens River.
Topics: Animals; Azinphosmethyl; Fresh Water; Insecta; Insecticides; Models, Biological; South Africa; Toxicity Tests; Water Pollutants, Chemical
PubMed: 12371494
DOI: No ID Found -
Journal of Economic Entomology Jun 2003Populations of obliquebanded leafroller, Choristoneura rosaceana Harris, and three-lined leafroller, Pandemis limitata Robinson, were obtained from seven sites in the...
Populations of obliquebanded leafroller, Choristoneura rosaceana Harris, and three-lined leafroller, Pandemis limitata Robinson, were obtained from seven sites in the Okanagan and Similkameen Valleys of British Columbia and assayed for their responses to three insecticides using a leaf disk bioassay. Lethal concentration ratios (LCRs) were calculated for all populations compared with a susceptible laboratory colony of C. rosaceana; significant variation was detected in response to all three insecticides. LCRs were 0.86-15.52 for azinphosmethyl, 0.38-2.37 for spinosad (Success), and 0.58-4.89 for Bacillus thuringiensis (Foray). Correlation analysis indicated no cross-resistance among the three insecticides. Leafroller populations obtained from apple orchards managed with organic production practices were more susceptible to azinphosmethyl than leafrollers obtained from conventionally managed sites. Conversely, the highest levels of tolerance to B. thuringiensis were observed in the populations from organic sites, possibly reflecting usage patterns; B. thuringiensis is one of the few insecticides allowed under organic production guidelines. All populations were highly susceptible to spinosad, which may be a useful tool for resistance management programs if used judiciously.
Topics: Animals; Azinphosmethyl; Bacillus thuringiensis; Drug Combinations; Insecticide Resistance; Insecticides; Lepidoptera; Macrolides; Trees
PubMed: 12852631
DOI: 10.1093/jee/96.3.879 -
Regulatory Toxicology and Pharmacology... Aug 2003We examined the effect of the 14-day agricultural restricted entry period on absorbed pesticide doses in a group of twenty experienced apple thinners. Thinners entered... (Comparative Study)
Comparative Study
We examined the effect of the 14-day agricultural restricted entry period on absorbed pesticide doses in a group of twenty experienced apple thinners. Thinners entered orchards 1-49 days following azinphosmethyl applications. Urine samples (n=296) collected throughout the thinning season were analyzed for the three dialkylphosphate metabolites of azinphosmethyl to estimate absorbed daily doses. Separate dose distributions were created for samples collected when the interval was <14 days, or 14 days or more; geometric mean doses for these two categories differed by a factor of two (42 and 19 microg/kg/day, respectively; p<0.0001). Dose estimates were compared to US Environmental Protection Agency and California EPA regulatory guidance values for occupational azinphosmethyl risk. None of the doses exceeded the U.S. EPA NOAEL (560 microg/kg/day), but nearly all had a margin of exposure of less than 100. Addition of a 10-fold uncertainty factor to California EPAs NOAEL produced a guidance value of 75 microg/kg/day. Only 2.4% of the doses exceeded this value for re-entry intervals 14 days or more, while 27% exceeded the value for re-entry intervals <14 days. We conclude that the 14-day restricted entry interval provides an appropriate level of worker health protection under the field conditions studied.
Topics: Agriculture; Azinphosmethyl; Dose-Response Relationship, Drug; Humans; Insecticides; No-Observed-Adverse-Effect Level; Occupational Exposure; Pesticide Residues; Risk Assessment; Skin Absorption; Time Factors; Washington
PubMed: 12878058
DOI: 10.1016/s0273-2300(03)00073-4 -
Frontiers in Neuroscience 2019Poisoning with organophosphorus compounds (OPCs) is a major problem worldwide. Standard therapy with atropine and established oxime-type enzyme reactivators... (Review)
Review
Poisoning with organophosphorus compounds (OPCs) is a major problem worldwide. Standard therapy with atropine and established oxime-type enzyme reactivators (pralidoxime, obidoxime) is unsatisfactory. In search of more efficacious broad-spectrum oximes, new bispyridinium (K-) oximes have been synthesized, with K027 being among the most promising. This review summarizes pharmacokinetic characteristics of K027, its toxicity and efficacy to protect from OPC toxicity and compares this oxime with another experimental bisquaternary asymmetric pyridinium aldoxime (K048) and two established oximes (pralidoxime, obidoxime). After intramuscular (i.m.) injection, K027 reaches maximum plasma concentration within ∼30 min; only ∼2% enter the brain. Its intrinsic cholinesterase inhibitory activity is low, making it relatively non-toxic. reactivation potency is high for ethyl-paraoxon-, methyl-paraoxon-, dichlorvos-, diisopropylfluorophosphate (DFP)- and tabun-inhibited cholinesterase. When administered after exposure to the same OPCs, K027 is comparable or more efficacious than pralidoxime and obidoxime. When given as a pretreatment before exposure to ethyl-paraoxon, methyl-paraoxon, DFP, or azinphos-methyl, it is superior to the Food and Drug Administration-approved compound pyridostigmine and comparable to physostigmine, which because of its entry into the brain may cause unwanted behavioral effects. Because of its low toxicity, K027 can be given in high dosages, making it a very efficacious oxime not only for postexposure treatment but also for prophylactic administration, especially when brain penetration is undesirable.
PubMed: 31191210
DOI: 10.3389/fnins.2019.00427