Some effects of intracerebral lead implantation in the rat.

Pellets of lead acetate were implanted into the forebrains of adult rats which were sacrificed at intervals between 4 days and 4 weeks thereafter. Parenchymal necrosis and a number of reactive changes including edema and macrophage invasion were observed. Lead deposits were found in the extracellular spaces and within macrophages but only to a slight extent within glial or meningeal cells. Vascular changes were quite remarkable and included proliferation and the appearance of fenestrated blood vessels as well as some with tubular bodies and striking increases in the number of pinocytotic vesicles.