UC Irvine

This study was designed to elucidate the cellular effects of hydrazine on four established tissue culture vertebrate cell lines (rat kangaroo kidney, Xenopus toad kidney, human diploid fibroblast, and Chinese hamster cells) and primary cultures of neonatal rat myocardial cells. Cells were exposed to hydrazine in various concentrations (0.001 to 10 mm) for varying time periods. The resulting growth and morphological data revealed a possible site of hydrazine action. In all cell lines tested, population growth was depressed by low concentrations of hydrazine (0.01 to 0.1 mm). Cell growth was initially depressed, but it eventually returned to normal log phase growth even when fresh hydrazine was added to the culture medium. At higher concentrations (0.5 to 2.0 mm), hydrazine was lethal. Most cell types first showed population growth depression at 0.01 mm hydrazine, but the lethal concentration varied with the cell type. Cultures treated with hydrazine yielded a significantly higher number of giant, multinucleated cells. Autoradiography studies employing [3H]thymidine confirmed that the large, multinucleated cells resulted from cell fusion. The increase in cell fusion in hydrazine treated cell cultures implicated the cell surface as a possible target site. Scanning electron microscopy confirmed concentration related surface differences between control and hydrazine-treated cells. Further membrane studies examining the effects of hydrazine on the contractile and intercellular spontaneous electrical activity of myocardial cells in culture indicated that hydrazine also altered these membrane-related activities in a concentration and time-dependent manner. © 1980, All rights reserved.