Tissue-Specific Effects of Chlorpyrifos on Carboxylesterase and Cholinesterase Activity in Adult Rats: An <i>in Vitro</i> and <i>in Vivo</i> Comparison

Chanda, Sushmita; Mortensen, Spencer R.; Moser, Virginia C.; Padilla, Stephanie

doi:10.1093/toxsci/38.2.148

Cited by 47 publications

(57 citation statements)

References 27 publications

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“…This observation is consistent with the presence of A-esterase in the blood of barn owl. Because ␣-⌵〈 can be hydrolyzed by various esterases, when a Ca 2ϩ -dependent A-esterase or a Ca 2ϩ -dependent arylesterase activity is present in plasma, the use of a chelating agent in the assay is needed to inhibit them (Chanda et al, 1997). By comparison with other raptor species, the presence of A-esterase activity in the blood of barn owl could be an efficient mechanism to detoxify the active oxon form of OP insecticides.…”

Section: Discussionmentioning

confidence: 99%

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Plasma B-Esterase Activities in European Raptors

Roy

Grolleau

Chamoulaud

et al. 2005

Journal of Wildlife Diseases

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B-esterases are serine hydrolases composed of cholinesterases, including acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), and carboxylesterase (CbE). These esterases, found in blood plasma, are inhibited by organophosphorus (OP) and carbamate (CB) insecticides and can be used as nondestructive biomarkers of exposure to anticholinesterase insecticides. Furthermore, B-esterases are involved in detoxification of these insecticides. In order to establish the level of these enzymes and to have reference values for their normal activities, total plasma cholinesterase (ChE), AChE and BChE activities, and plasma CbE activity were determined in 729 European raptors representing 20 species, four families, and two orders. The diurnal families of the Falconiforme order were represented by Accipitridae and Falconidae and the nocturnal families of the Strigiforme order by Tytonidae and Strigidae. Intraspecies differences in cholinesterase activities according to sex and/or age were investigated in buzzards (Buteo buteo), sparrowhawks (Accipiter nisus), kestrels (Falco tinnunculus), barn owls (Tyto alba), and tawny owls (Strix aluco). Sex-related differences affecting ChE and AChE activities were observed in young kestrels (2-3-mo-old) and age-related differences in kestrels (ChE and AChE), sparrowhawks (AChE), and tawny owls (ChE, AChE, and BChE). The interspecies analysis yielded a negative correlation between ChE activity and body mass taking into account the relative contribution of AChE and BChE to ChE activity, with the exception of the honey buzzard (Pernis apivorus). The lowest ChE activities were found in the two largest species, Bonelli's eagle (Hieraaëtus fasciatus) and Egyptian vulture (Neophron percnopterus) belonging to the Accipitridae family. The highest ChE activities were found in the relatively small species belonging to the Tytonidae and Strigidae families and in honey buzzard of the Accipitridae family. Species of the Accipitridae, Tytonidae, and Strigidae families were characterized by a BChE contribution that dominated the total ChE activity, while in the species of the Falconidae family, AChE activity dominated. With the exception of the barn owl, CbE activity (eserine-insensitive ␣-naphthyl acetate esterase [␣-⌵〈⌭] activity) in all species was almost absent or very low. The values obtained in this study for ChE, AChE, and BChE activities and the AChE:BChE ratios for buzzard, kestrel, barn owl, and tawny owl provide a good estimate of the normal values in free-living individuals of these European species. They can be used as a baseline to evaluate the effect of anticholinesterase insecticides in the field.

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Section: Discussionmentioning

confidence: 99%

“…This role has been widely studied in mammals (Maxwell et al, 1991;Maxwell, 1992a;Chanda et al, 1997;Yang and Dettbarn, 1998) and more recently in birds (Parker and Goldstein, 2000). In mammals, this detoxification role is primarily attributed to CbE, which is found in large amounts compared with cholinesterases.…”

Section: Introductionmentioning

confidence: 99%

Plasma B-Esterase Activities in European Raptors

Roy

Grolleau

Chamoulaud

et al. 2005

Journal of Wildlife Diseases

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“…Inactivation of acetylcholinesterase results in the accumulation of acetylcholine, causing overstimulation of cholinergic nerves. (Chanda et al, 1997;Ecobichon, 2001).…”

mentioning

confidence: 99%

Human Hepatic Cytochrome P450-Specific Metabolism of Parathion and Chlorpyrifos

Foxenberg

McGarrigle²,

Knaak³

et al. 2007

Drug Metabolism and Disposition

122

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ABSTRACT:Organophosphorus pesticides (OPs) remain a potential concern to human health because of their continuing worldwide use. Thiophosphorus OPs, once bioactivated by cytochromes P450 (P450s), form oxon metabolites, which are potent acetylcholinesterase inhibitors. This study investigated the rate of desulfation (activation) and dearylation (detoxification) of parathion and chlorpyrifos in human liver microsomes. In addition, recombinant human P450s were used to quantify, for the first time, the P450-specific kinetic variables (K m and V max ) for each compound for future use in refining human physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) models of OP exposure. CYP1A2, 2B6, 2C9, 2C19, 3A4, 3A5, and 3A7 were found to be active to a widely varying degree in parathion metabolism, whereas all, with the exception of CYP2C9, were also found to be active in chlorpyrifos metabolism. P450-specific kinetic parameters for OP metabolism will be used with age-dependent hepatic P450 content to enhance PBPK/PD models so that OP exposures can be modeled to protect human health in different age groups.

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“…Considerable evidence suggests that immature detoxification mechanisms in the young account for much of the reported age-related differences in sensitivity (e.g., Atterberry et al 1997;Benke and Murphy 1975;Chanda et al 1997;Mendoza 1976;Mortensen et al 1996;Sterri et al 1985). All of these chemicals are detoxified through a combination of P450 microsomal enzymes, carboxylesterases, and/or A-esterases, but the metabolic patterns differ greatly (Chambers et al, 2010).…”

Section: Kineticsmentioning

confidence: 99%

“…All of these chemicals are detoxified through a combination of P450 microsomal enzymes, carboxylesterases, and/or A-esterases, but the metabolic patterns differ greatly (Chambers et al, 2010). For some chemicals such as chlorpyrifos, sensitivity in young rats has been directly correlated with maturing carboxylesterase and A-esterase systems (Chanda et al 1997(Chanda et al ,. 2002Karanth and Pope 2000;Mortensen et al 1996;.…”

Section: Kineticsmentioning

confidence: 99%

Age-Related Differences in Acetylcholinesterase Inhibition Produced by Organophosphorus and N-Methyl Carbamate Pesticides

Moser¹

2011

Pesticides in the Modern World - Pests Control and Pesticides Exposure and Toxicity Assessment

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Tissue-Specific Effects of Chlorpyrifos on Carboxylesterase and Cholinesterase Activity in Adult Rats: An in Vitro and in Vivo Comparison

Cited by 47 publications

References 27 publications

Plasma B-Esterase Activities in European Raptors

Plasma B-Esterase Activities in European Raptors

Human Hepatic Cytochrome P450-Specific Metabolism of Parathion and Chlorpyrifos

Age-Related Differences in Acetylcholinesterase Inhibition Produced by Organophosphorus and N-Methyl Carbamate Pesticides

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