Dieldrin toxicity and successive discrimination reversal in squirrel monkeys<i>(Saimiri sciureus)</i>

Rm, Smith; Wl, Cunningham; Ga, Van Gelder; Gg, Karas

doi:10.1080/15287397609529372

Cited by 14 publications

(3 citation statements)

References 13 publications

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“…It is lipophilic and readily bioaccumulates in animals and humans. Dieldrin exposure during adulthood resulted in deficits in visual discrimination-reversal learning in both sheep (123) and squirrel monkeys (124) and caused rats to make more errors on a zig-zag maze (125). In contrast, one study of perinatal exposure to dieldrin reported facilitated retention of learning on a symmetrical maze (126).…”

Section: Effects Of Endocrine-disrupting Chemicals On Cognitionmentioning

confidence: 96%

Cognitive effects of endocrine-disrupting chemicals in animals.

Schantz

Widholm

2001

Environ Health Perspect

220

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A large number of chemical pollutants including phthalates, alkylphenolic compounds, polychlorinated biphenyls and polychlorinated dibenzodioxins, organochlorine pesticides, bisphenol A, and metals including lead, mercury, and cadmium have the ability to disrupt endocrine function in animals. Some of these same chemicals have been shown to alter cognitive function in animals and humans. Because hormonally mediated events play a central role in central nervous system development and function, a number of researchers have speculated that the changes in cognitive function are mediated by the endocrine-like actions of these chemicals. In this paper we review the evidence that cognitive effects of chemicals classified as environmental endocrine disruptors are mediated by changes in hormonal function. We begin by briefly reviewing the role of gonadal steroids, thyroid hormones, and glucocorticoids in brain development and brain function. We then review the endocrine changes and cognitive effects that have been reported for selected endocrine-disrupting chemicals, discuss the evidence for causal relationships between endocrine disruption and cognitive effects, and suggest directions for future research.

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Section: Effects Of Endocrine-disrupting Chemicals On Cognitionmentioning

confidence: 96%

Cognitive effects of endocrine-disrupting chemicals in animals.

Schantz

Widholm

2001

Environ Health Perspect

220

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“…From these findings we conclude that prolonged exposure to dieldrin in vitro led to reduced performance of the GABA A and glutamate receptors, which may be predictive of deleterious consequences in vivo because NMDA receptor is involved in memory and learning processes. In fact, behavioral and learning deficits have been observed in monkeys chronically dosed with dieldrin (Smith et al, 1976 (Briz et al, 2011). These effects of dieldrin on ER levels and activation might contribute to cognitive and behavioral deficits (Schantz and Widholm, 2001).…”

Section: Cell-based Methods For Predicting Neurotoxicity Of Environmementioning

confidence: 99%

Strategies and tools for preventing neurotoxicity: To test, to predict and how to do it

Llorens

Ceccatelli

et al. 2012

NeuroToxicology

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A change in paradigm is needed in the prevention of toxic effects on the nervous system, moving from its the present reliance solely on data from animal testing to a prediction model mostly based on in vitro toxicity testing and in silico modelling.According to the report published by the National Research Council (NRC) of the US National Academies of Science, high-throughput in vitro tests will provide evidence for alterations in "toxicity pathways" as the best possible method of large scale toxicity prediction. The challenges to implement this proposal are enormous, and provide much room for debate. While many efforts address the technical aspects of implementing the vision, many questions around it need also to be addressed. Is the overall strategy the only one to be pursued? How can we move from current to future paradigms? Will we ever be able to reliably model for chronic and developmental neurotoxicity in vitro?.

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“…In a neurobehavioral study of the effect of dieldrin on successive "discrimination reversals", 90 day old male squirrel monkeys were administered oral doses of 0.01 mg/kg bw per day and 0.1 mg/kg bw per day (3 and 4 animals per group respectively, with 2 animals in a control group) for 55 days (Smith et al, 1976). The higher dose was considered to cause impaired learning.…”

Section: Neurotoxicitymentioning

confidence: 99%

Opinion of the Scientific Panel on Plant protection products and their Resi-dues on a request from the Commission on the risks associated with an in-crease of the MRL for dieldrin on courgettes

2007

EFSA Journal

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SUMMARYFollowing a request from the European Commission, the Panel on Plant Protection Products and their Residues (PPR Panel) was asked to deliver a scientific opinion on the risks associated with an increase of the MRL for dieldrin on courgettes.Dieldrin was developed in the 1940s and was widely used as an insecticide up to the early 1970s. However, its use was stopped when it became clear that it has very unfavourable environmental and toxicological characteristics. Today, dieldrin is therefore banned in most countries of the world. Moreover, it is on the list of the Stockholm Convention to protect human health and the environment from persistent organic pollutants.Dieldrin is very persistent in the environment and has a strong potential to accumulate in the food chain. Due to the very slow environmental degradation of the substance, dieldrin is still a widespread soil contaminant in Europe and other places. When growing courgettes on such soils, residues can be taken up by the plants and transported to the fruits. Monitoring data from The Netherlands show that courgettes grown in greenhouses from the western part of the country do not always comply with the existing MRL of 0.02 mg/kg. The Netherlands has therefore requested an increase of this MRL-value to 0.05 mg/kg and the European Commission has asked EFSA to evaluate the toxicological implications of the proposed new MRL-value.The main reasons for prohibiting the active substance were its environmental persistence and its tendency to accumulate in animal tissues. It is therefore appropriate to ask whether exposure as a result of eating courgettes with an increased MRL, together with other known sources of exposure (e.g. through animal products), represents a potential risk for European consumers in the long as well as in the short term.The residue definition for dieldrin under current EU residue guidelines specifies dieldrin "singly or combined with aldrin, expressed as dieldrin". This definition reflects the close chemical and toxicological relationship between these two cyclodiene insecticides. There are two isomers of dieldrin, the exo-and the endo-form. Dieldrin itself is the exo-isomer. The PPR Panel 2 briefly reviewed the characteristics of the different isomeric forms of dieldrin and concluded that focus should be on the exo-form of the substance, i.e. dieldrin itself. The Panel agreed not to include photodieldrin -an environmental product of dieldrin -in further consideration because this substance is not included in the residue definition. Furthermore photodieldrin has not been studied in such detail and the literature and data on the occurrence and fate of its residue are scarce.The Joint FAO/WHO Meeting on Pesticide Residues (JMPR) established an acceptable daily intake (ADI) for dieldrin in 1967, confirmed this in 1977 and converted (but not re-evaluated) it to a PTDI (Provisional Tolerable Daily Intake) in 1994. JMPR has not derived an acute reference dose (ARfD) for dieldrin. The propensity of dieldrin to accumulate in biological organisms...

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Dieldrin toxicity and successive discrimination reversal in squirrel monkeys(Saimiri sciureus)

Cited by 14 publications

References 13 publications

Cognitive effects of endocrine-disrupting chemicals in animals.

Cognitive effects of endocrine-disrupting chemicals in animals.

Strategies and tools for preventing neurotoxicity: To test, to predict and how to do it

Opinion of the Scientific Panel on Plant protection products and their Resi-dues on a request from the Commission on the risks associated with an in-crease of the MRL for dieldrin on courgettes

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