ULTRASTRUCTURAL STUDIES ON THE CYTO-TOXIC EFFECTS OF MERCURIC-CHLORIDE ON MOUSE GLIOMA

Cytotoxic effects of mercuric chloride on cultured mammalian cells were studied by light and electron microscopy. Cell proliferation of mouse glioma was completely suppressed by treatment with 5 × 10-5 m mercuric chloride. The mitotic index remained at the control level for 4 hr after treatment but decreased afterward. The amount of mercuric mercury bound to the cells increased markedly above 2 × 10-5 m mercuric chloride. Electron microscopic examination revealed many kinds of changes of organelles in cells exposed to 5 × 10-5 m mercuric chloride for 4 hr: Nuclei were transformed into pyknotic and irregular shapes; mitochondria lost their normal cristae and abnormal electron dense-areas were present within the matrix; polyribosomes were dispersed. Numerous electron-dense granules and vacuolations were seen in the cytoplasm, especially around the Golgi region. However, microtubules were still evident, although the amount seemed to decrease compared with control cells. Thus, the inhibition of growth by mercuric chloride may be ascribed to the degenerative changes which occur in many organelles. © 1979.