Effects of antimitotic drugs on the morphological features of PC12 cells in culture--a light and EM study.

PC12 cells were grown in monolayer cultures either as untreated controls or treated with (1) NGF, (2) mitomycin C/BUdR, or (3) a combination of NGF and mitomycin C/BUdR. The cells from these four groups were processed for scanning and transmission electron microscopy and for fluorescence histochemistry. With scanning electron microscopy, the control and mitomycin C/BUdR treated cells showed the presence of very small extensions for attachment, and numerous fine processes on the cell surface, while the NGF treated cells and cells treated with the combination exhibited many large processes that were even longer with the combination treatment. The combination treatment also inhibited cell growth completely. Fluorescence histochemical studies revealed strong fluorescence in the perikarya of cells from all the four groups. Transmission electron microscopic studies showed that the cells in all the four groups contained many chromaffin-type granules in addition to the presence of other cellular organelles. The neurites in the NGF group and the combination treatment also contained these granules and well-defined microtubules. Therefore, antimitotic agents inhibit PC12 cell growth without affecting important cellular parameters.