In vitro and In vivo effects of Manganese (MnCl2) and Lead (Pb acetate)

Abstract

The effects of MnCl2 (1, 10, 100 nM, 1, 10, 100 μM, 1mM) and Pb acetate (1, 10, 100 nM, 1, 10, 100 μM, 1mM) on PC12 cell viability after exposure for 24 and 48 hours were examined using the MTT assay. Exposure to MnCl2 (Mn) and Pb acetate (Pb) produced dose‐dependent decreases in cell viability. Percent viability from exposure for 48 hours was less than that from 24 hours. In the in vivo study, pregnant Sprague Dawley rats were exposed during perinatal period to MnCl2 (1.25, 5 and 10 mg/mL) and Pb acetate (2.5–25, 100–250 and 2500–4000 μg/mL), and the effects on neurobehavioral and neurochemical outcomes were determined in the offspring. Exposures to Mn and Pb led to dose‐dependent impairment of learning and memory, evaluated at PND 35 with the Morris water maze. Impulsivity and locomotor activity were also adversely affected when evaluated with the elevated plus maze (EPM) at PND 56. Mn exposure also attenuated high K+‐ evoked increases in extracellular dopamine (DA) and glutamate (Glu), as determined by in vivo microdialysis. Pb similarly attenuated GLU neurotransmission, but had no effect on DA. Impairments in neurotransmission might underlie some of the neurocognitive/neurobehavioral deficits found in this study.