Repeated exposure to chlorpyrifos leads to prolonged impairments of axonal transport in the living rodent brain

摘要: Abstract The toxicity of the class chemicals known as organophosphates (OP) is most commonly attributed to inhibition enzyme acetylcholinesterase. However, there significant evidence that this mechanism may not account for all deleterious neurologic and neurobehavioral symptoms OP exposure, especially those associated with levels produce no overt signs acute toxicity. In study described here we evaluated effects used OP-pesticide, chlorpyrifos (CPF) on axonal transport in brains living rats using manganese (Mn 2+ )-enhanced magnetic resonance imaging (MEMRI) optic nerve (ON) projections from retina superior colliculus (SC). T1-weighted MEMRI scans were at 6 24 h after intravitreal injection Mn . As a positive control deficits, initial studies conducted tropolone alkaloid colchicine administered by injection. subsequent both single repeated exposures CPF MEMRI. expected, (2.5 μg) produced robust decrease along (SC) (as indicated reduced contrast). A subcutaneous (s.c.) (18.0 mg/kg) was alterations Conversely, 14-days s.c. exposure (18.0 mg/kg/day) decreased ONs SC, an effect also present 30-day (CPF-free) washout period. These results indicate pesticide, can result persistent mammalian brain. Given fundamental importance neuronal function, these observations (at least part) explain some long term neurological deficits have been observed humans who repeatedly exposed doses OPs