Alkylmercurial encephalopathy in the monkey (Saimiri sciureus and Macaca arctoides): a histopathologic and autoradiographic study.

Histopathologic and autoradiographic studies were performed on monkeys of the genera Saimiri and Macaca after acute and chronic oral exposure to several dosage regimens of methylmercuric chloride (MeHg). Neuropathologic changes were primarily cortical, although subcortical lesions also were observed. Autoradiographic localization of 203-Hg was greatest within glial cells (particularly Nissl-pump astrocytes, subependymal glia and Bergmann's glia) and mast cells. High levels of label within normal appearing large neurons (particularly those within Gasserian and dorsal root ganglia) indicate a lower susceptibility of these neurons to the toxic effects of MeHg. Blood and brain levels of mercury correlated well with the degree of neuropathologic change, but individual variations in susceptibility to intoxication also existed.