Effect of developmental chlorpyrifos exposure, on endocannabinoid metabolizing enzymes, in the brain of juvenile rats.
Toxicol Sci
; 122(1): 112-20, 2011 Jul.
Article
em En
| MEDLINE
| ID: mdl-21507991
ABSTRACT
The endogenous cannabinoids 2-arachidonoylglycerol (2-AG) and arachidonoyl ethanolamide (AEA or anandamide) play vital roles during nervous system development including regulating axonal guidance and synaptogenesis. The enzymatic degradation of 2-AG and AEA is highly susceptible to inhibition by organophosphate compounds in vitro. Furthermore, acute in vivo exposure of adult animals to the agricultural insecticide chlorpyrifos (CPS) caused moderate inhibition of both 2-AG and AEA hydrolysis. However, the effects of repeated exposure to lower levels of CPS, especially during development, on endocannabinoid metabolism in the brain is not known. To examine this, rat pups were orally exposed daily from postnatal days 10-16 to either 1.0, 2.5, or 5.0 mg/kg CPS. Body weight gain was reduced by 5.0 mg/kg on all days of treatment whereas 2.5 mg/kg reduced the weight gain only on the last two days of treatment. At 4-h postexposure on day 16, forebrain cholinesterase (ChE) activity and hydrolysis of 2-AG and AEA were inhibited in a dose-related manner, and the extent of inhibition from highest to lowest level was AEA hydrolysis > ChE activity > 2-AG hydrolysis. The extent of inhibition of AEA hydrolysis was approximately twice than that of ChE activity with AEA hydrolysis being virtually eliminated by 2.5 and 5.0 mg/kg and 1.0 mg/kg causing 40% inhibition. The sensitivity of AEA hydrolysis, compared with canonical targets such as ChE activity, suggests a potential alternative developmental target for CPS. Inhibition of AEA hydrolysis could result in accumulation of endocannabinoids, which could alter normal endocannabinoid transmission during brain maturation.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Encéfalo
/
Endocanabinoides
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Clorpirifos
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Exposição Ambiental
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Moduladores de Receptores de Canabinoides
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Inseticidas
Tipo de estudo:
Guideline
Limite:
Animals
Idioma:
En
Revista:
Toxicol Sci
Assunto da revista:
TOXICOLOGIA
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Estados Unidos