The stimulation of the transition of resting NIH 3T3 cells to proliferation under exposure to lysosomal inhibitors

Lysosomal inhibitors (amino acid methyl esters) and the platelet-derived growth factor stimulate the resting NIH 3T3 cells to enter the S period. Incubation of cells in the medium containing lysosomal inhibitors enhances protein accumulation and seemingly does not disrupt lysosomes. These results indicate that proliferative homeostasis depends on the metabolic status of cells and that catabolic processes activated in resting cells negatively influence the prereplicative reactions.