Ultrastructural modifications of rat liver cells induced by lead nitrate

Lead nitrate administration dramatically modified liver cells and sinusoids assayed by scanning and transmission electron microscopy. Hepatocytes became more roundish and many apoptot‐ic cells were visible both inside the parenchyma and in the sinusoidal lumen. Many of the those free in the sinusoids, probably derives from Kupffer cells, since their number was apparently reduced and some showed nuclear chromatin condensation. The remaining healthy Kupffer cells were often observed present beneath the endothelial wall into the space of Disse or between the disconnected hepatocytes. Except for scarce signs of apoptosis and a reduced number of fenestrae that were sometimes observed, the endothelial lining cells appeared almost healthy. At the longer times following treatment, further modifications of the liver were described: the presence of fribrotic materials, many sinusoids destroyed and enlarged spaces between hepatocytes.