Absorption and distribution of intubated insecticides in fasted mice

Ahdaya, S.M.; Monroe, R. J.; Guthrie, F. E.

doi:10.1016/0048-3575(81)90070-5

Cited by 24 publications

(8 citation statements)

References 15 publications

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“…Nolan et al (1984) studied the rate of chlorpyrifos absorption by oral administration of pesticide to humans and determined that 70 % was absorbed within 48 h whereas in rats and mice this took a little longer (48–60 h) (Ahdaya et al 1981). Smith et al (1967) reported that chlorpyrifos residues were predominantly deposited in fatty tissues.…”

Section: Resultsmentioning

confidence: 99%

Efficiency of the intestinal bacteria in the degradation of the toxic pesticide, chlorpyrifos

2012

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Chlorpyrifos (CP) is the most commonly used pesticide throughout the world. Its widespread use in agriculture and its potential toxicity to humans from ingestion of CP contaminated food have raised concerns about its risk to health. Human intestinal microflora has the ability to degrade pesticides, but the exact mechanisms involved and the metabolite end-products formed are not well understood. The primary objective of this work was to analyse the in vitro degradation of CP by five model intestinal bacteria namely Lactobacillus lactis, L. fermentum, L. plantarum, Escherichia coli and Enterococcus faecalis. Plate assay results revealed that L. lactis, E. coli and L. fermentum could grow with high concentrations of CP (>1,400 μg/mL), whereas E. faecalis and L. plantarum could grow with concentrations as low as 400 and 100 μg/mL, respectively. The best three CP degraders were therefore used in further experiments. The degradation of CP-induced organophosphorous phosphatase (OPP) production and that OPP concentration were higher in the supernatant (extracellular) rather than inside the cells by factor of up to 28. L. fermentum degraded 70 % CP with 3,5,6-trichloro-2-pyridinol (TCP) detected as the end product. L.lactis degraded up to 61 % CP with chlorpyrifos oxon detected as the end product, whereas E.coli degraded a lesser concentration (16 %) to chlorpyrifos-oxon and diethylphosphate.

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Section: Resultsmentioning

confidence: 99%

Efficiency of the intestinal bacteria in the degradation of the toxic pesticide, chlorpyrifos

2012

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“…Thus, an absorption fraction of 1.0 was used in the chlorpyrifos exposure model, with a uniform uncertainty distribution ranging from 0.8 to 1.0 (Table 17) . Nolan et al (1984) reported that in a study on humans, 70% of an ingested dose of chlorpyrifos was absorbed in 48 h. Bakke et al ( 1976) , Ahadaya et al ( 1981) , and Smith et al (1967) found that 90% of an administered dose of in an acute oral exposure was absorbed in rats. Thus, a constant absorption value of 0.7 was used for all simulated individuals and ingested media in the chlorpyrifos exposure model (assumes that the variation between individuals in the population is small) , with a uniform uncertainty distribution ranging from 0.5 to 0.9 (Table 17) .…”

Section: Absorption Factorsmentioning

confidence: 99%

Modeled estimates of chlorpyrifos exposure and dose for the Minnesota and Arizona NHEXAS populations

Buck

Özkaynak

Xue³

et al. 2001

J Expo Sci Environ Epidemiol

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This paper presents a probabilistic, multimedia, multipathway exposure model and assessment for chlorpyrifos developed as part of the National Human Exposure Assessment Survey ( NHEXAS) . The model was constructed using available information prior to completion of the NHEXAS study. It simulates the distribution of daily aggregate and pathway -specific chlorpyrifos absorbed dose in the general population of the State of Arizona ( AZ) and in children aged 3 ± 12 years residing in Minneapolis ± St. Paul, Minnesota ( MSP) . Pathways included were inhalation of indoor and outdoor air, dietary ingestion, non -dietary ingestion of dust and soil, and dermal contact with dust and soil. Probability distributions for model input parameters were derived from the available literature, and input values were chosen to represent chlorpyrifos concentrations and demographics in AZ and MSP to the extent possible. When the NHEXAS AZ and MSP data become available, they can be compared to the distributions derived in this and other prototype modeling assessments to test the adequacy of this pre -NHEXAS model assessment. Although pathway -specific absorbed dose estimates differed between AZ and MSP due to differences in model inputs between simulated adults and children, the aggregate model results and general findings for simulated AZ and MSP populations were similar. The major route of chlorpyrifos intake was food ingestion, followed by indoor air inhalation. Two -stage Monte Carlo simulation was used to derive estimates of both interindividual variability and uncertainty in the estimated distributions. The variability in the model results reflects the difference in activity patterns, exposure factors, and concentrations contacted by individuals during their daily activities. Based on the coefficient of variation, indoor air inhalation and dust ingestion were most variable relative to the mean, primarily because of variability in concentrations due to use or no -use of pesticides. Uncertainty analyses indicated a factor of 10 ± 30 for uncertainty of model predictions of 10th, 50th, and 90th percentiles. The greatest source of uncertainty in the model stems from the definition of no household pesticide use as no use in the past year. Because chlorpyrifos persists in the residential environment for longer than a year, the modeled estimates are likely to be low. More information on pesticide usage and environmental concentrations measured at different post -application times is needed to refine and evaluate this and other pesticide exposure models.

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“…But there are several reports that carbofuran is a rapidly degrading pesticide, hence its effects may not be as severe as we anticipate (Ahdaya et al, 1981;Kearney and Kaufman, 1975). The frequency of breaks and gaps was not significant enough to warrant such a situation, as the experiments were carried out on nucleated somatic cells and not germ cells.…”

Section: Discussionmentioning

confidence: 73%

Cytogenetic Biomarkers of Carbofuran Toxicity Utilizing Human Lymphocyte Cultures In Vitro

Naravaneni¹,

Jamil²

2005

Drug and Chemical Toxicology

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Short-term lymphocyte cultures from human peripheral blood samples were incubated with various aliquots of the carbofuran pesticide. After 48 h of initiation and 24 h of exposure to the carbofuran pesticide aliquots, it was seen that carbofuran caused an increase in the frequency of chromosomal aberrations, and the increase was significant (p < 0.05) in treated samples compared to controls. Karyotype analysis revealed more satellite associations, gaps, and breaks in treated samples. Single-strand breaks in the DNA assessed by comet assay revealed that the pesticide caused increase in the comet tail length implicating genotoxicity in somatic cells. The LD(50) of carbofuran was found to be 18 microM as calculated by probit analysis and determined by trypan blue dye exclusion method. The results presented here indicate that in vitro assays could be used as indicators of cyto- and genotoxicity of the pesticide, and their end points could be used as biomarkers.

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Absorption and distribution of intubated insecticides in fasted mice

Cited by 24 publications

References 15 publications

Efficiency of the intestinal bacteria in the degradation of the toxic pesticide, chlorpyrifos

Efficiency of the intestinal bacteria in the degradation of the toxic pesticide, chlorpyrifos

Modeled estimates of chlorpyrifos exposure and dose for the Minnesota and Arizona NHEXAS populations

Cytogenetic Biomarkers of Carbofuran Toxicity Utilizing Human Lymphocyte Cultures In Vitro

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