The susceptibility of various cultured cells to induction of clear cytoplasmic vacuoles by disobutamide

Cultured cells were found to be highly useful for investigating intracellular storage of amphiphilic compounds using disobutamide as a model agent. To select types of cultured cells most suitable for investigations, cells of dog coronary artery muscle, rabbit aorta muscle, rat urinary bladder carcinoma, rat basophilic leukaemia, human skin fibroblasts, bovine aorta endothelium, Chinese hamster ovary tumour and mouse fibroblasts were incubated with 0, 1, 2, 4, 6, 8 and 10 × 10^-4 m-disobutamide for 24 hr. Cultures were examined in situ by phase light microscopy for the presence of clear cytoplasmic vacuoles, cell death (cell detachment), and for drug effect on confluency/cell count. Disobutamide induced vacuoles in all cell types except rat leukaemia. The drug induced cell death and reduction in confluency or cell count in cultures of all cell types except rat carcinoma and rabbit aorta muscle. Release of lactic dehydrogenase from cells confirmed the relative resistance of the rat carcinoma and rabbit cells, and susceptibility of rat leukaemia, to drug-induced cell death. By means of electron microscopy of rat carcinoma and rabbit cells, it was established that vacuoles were membrane-bound and their content was predominantly electron-lucent.