Gender-dependent behavioural impairment and brain metabolites in young adult rats after short term exposure to lead acetate

We investigated the behavioural effects of short-term lead (Pb) exposure in adult rats producing blood Pb concentration (<10 μg/dL) below those associated with neurological impairment in occupationally exposed individuals. In order to assess gender differences, we performed parallel behavioural experiments in male and female rats. Exposure to Pb acetate (50 mg/L in drinking water) for 30–45 days induced behavioural alterations consisting in hyperactivity in a novel environment and impairment of spatial memory. These effects were observed only in male rats. Object recognition, motor coordination were unaffected by Pb exposure. Magnetic resonance spectroscopy allows in vivo assessment of main brain metabolites (glutamate/glutamine, creatine, myoinositol, N-acetylaspartate and choline) whose changes have been demonstrated in several central nervous system pathologies. Exposure to Pb did not affect metabolite profile in the striatum and increase myoinositol signal in the hippocampus of male rats. The increase in myoinositol in hippocampus suggests early Pb-induced alteration in glial metabolism in this brain region and may represent a potential marker of early brain dysfunction during Pb exposure.

► Blood lead levels <10 μg/dL are considered tolerable for lead-exposed workers.
► Short-term exposure to lead acetate induces subtle behavioural impairment only in male rats.
► Behavioural impairment is accompanied by an increase of myoinositol in hippocampus.