ISSN:
0021-9541
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
In culture medium supplemented with 10% clotted blood serum, the saturation density of BALB/c-3T3 cells is determined jointly by cell replication and cell loss. By prelabelling cellular DNA with 3H-thymidine and also by time lapse photography, we studied cell loss independently of replication. Cell loss was accelerated when BALB/c-3T3 cells were transferred from serum-supplemented medium, which contains the platelet derived growth factor (PDGF), to medium supplemented with platelet-poor plasma which lacks it. Loss occurred via the disintegration of cell attached to the surface of the tissue culture dish. Cytolysis of individual cells occurred rapidly; less than 15 minutes transpired between the first indication of a perturbance (by phase contrast microscopy) and fragmentation of the cell cytoplasm. Kinetic analysis was consistent with random cell death rather than a fixed lifetime.The percentage of cells undergoing cytolysis was governed by the cell density; at high densities, such as are present in confluent cultures, a higher percentage of cell loss was noted than at low density. Cell death was antagonized by partially purified or electrophoretically homogenous preparations of-PDGF. Pure PDGF stimulated cell survivial at ng/ml in a concentration dependent fashion. The process of cell replication was not necessary for survival because PDGF prevented cytolysis in the presence of methotrexate, an inhibitor of DNA synthesis. A brief (4 hour) treatment with PDGF prevented cell death; such PDGF treated cells displayed increased survival after being taken up with trypsin and planted onto a fresh surface in plasma supplemented medium. Pituitary fibroblast growth factor, a functional analogue of PDGF for induc of DNA synthesis in BALB/c-3T3 cells, also functioned as an anticytolytic agent. By contrast, epidermal growth factor and insulin did not. Cytolysis of SV40-transformed cells occurred at a constitutively low rate and was insensitive to PDGF.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jcp.1041130205
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