The relation between protein synthesis and lipide accumulation in L strain cells and Ehrlich ascites cells.

It has long been known that fat accumulates in old injured cells both in tissue culture and in many mammalian disease states. The use of L cells grown in suspension tissue culture permitted the opportunity to study conditions in which lipide accumulation could be retarded or accelerated. These cultures exhibit a three-phase growth curve which is similar to that previously found with bacteria and consists of a lag period, logarithmic growth period, and stationary period. Daily aliquots were removed from cultures going through these phases and protein and cholesterol content correlated with cell division. It was found that L cells gradually accumulated lipide in the cell concurrent with retardation of cell division and protein synthesis. Conversely old lipide-laden cells, placed in fresh media and encouraged to active division with net protein synthesis progressed from a high to a low lipide/cell ratio over a period of 2 to 4 days. An amino acid analogue p-fluorophenylalanine and a mitotic inhibitor, colchicine, also markedly increased the lipide/cell ratio. Similar results were found in in vitro experiments with Ehrlich ascites cells.