Bisphenol A (BPA) is an important industrial chemical used as the monomer for polycarbonate plastic and in epoxy resins for food can liners. Worldwide biomonitoring studies consistently find a high prevalence of BPA conjugates in urine (>90%) in amounts consistent with aggregate exposure at levels below 1 μg/kg bw/d. The current study used LC/MS/MS to measure concurrently the pharmacokinetics of aglycone (active) and conjugated (inactive) deuterated BPA (d6) in maternal and fetal rhesus monkey serum, amniotic fluid, and placenta following intravenous injection in the dam (100 μg/kg bw).
View Article and Find Full Text PDFDevelopmental exposure to the organophosphorus pesticides chlorpyrifos and diazinon (DZN) alters serotonergic synaptic function at doses below the threshold for cholinesterase inhibition, however there are some indications that the two agents may differ in several important attributes. Previously, we found that low-dose chlorpyrifos exposure in neonatal rats causes lasting changes in emotional response and in the current study we did a comparable evaluation for DZN. Male and female Sprague-Dawley rat pups (N=10-12 of each sex per treatment group) were given 0, 0.
View Article and Find Full Text PDFHistamine H(1) blockade is one of the more prominent actions of the multi-receptor acting antipsychotic clozapine. It is currently not known how much this H(1) antagonism of clozapine contributes to the therapeutic or adverse side effects of clozapine. The current studies with Sprague-Dawley rats were conducted to determine the participation of histaminergic H(1) receptor subtype in sensorimotor plasticity and memory function affected by clozapine using tests of prepulse inhibition (PPI) and radial-arm maze choice accuracy.
View Article and Find Full Text PDFRecent studies raise concern for combined exposure to polychlorinated biphenyls (PCBs) and methylmercury (MeHg), two environmental contaminants that are found in fish and seafood. Past accidental poisonings in humans show that exposure to high levels of either contaminant is associated with motor impairments, including alterations in cerebellar functions such as balance and coordination. Epidemiological studies of lower level exposures suggest some neuromotor impairment in exposed children, but the majority of these studies have focused on cognitive endpoints rather than examining a full-range of motor function.
View Article and Find Full Text PDFWe recently reported that rats exposed to PCBs and MeHg during development were impaired on the rotating rod, a test of balance and coordination that is often indicative of cerebellar damage. In addition, developmental PCB exposure is known to dramatically reduce circulating thyroid hormone concentrations, which may have a negative impact on cerebellar development. Therefore, we investigated the effects of combined PCB and MeHg exposure on Purkinje cells and the cerebellum.
View Article and Find Full Text PDFDietary n-3 fatty acid (FA) deficiencies during development can cause learning and memory impairments, but the functional effects of dietary n-6 FA deficiencies, reflected in a lowered n-6/n-3 ratio, are less clear. We investigated the effects of maternal diets containing fish oils, resulting in lowered n-6/n-3 ratios, on a spatial working memory task in their offspring. Starting on gestational day 6, Sprague-Dawley timed-pregnant rats were placed on one of three experimental diets: control (unadulterated powdered rat chow), Pacific Ocean (PO) fish (powdered rat chow containing 20% (w/w) lyophilized PO salmon), or PO oil (powdered rat chow containing 6% (w/w) oil extracted from PO salmon).
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