The different roles of serum and calcium in the control of proliferation of BALB/c 3T3 mouse cells.

Abstract

Proliferatively inactive BALB/c 3T3 mouse cells in dense cultures initiate a growth-division cycle upon exposure to fresh calf serum in a low-calcium (0.01 mM) medium. If these calcium-deprived cells are not supplied with calcium sometime during the first 10 hours after serum stimulation, they will rapidly return to a proliferatively inactive state without initiating DNA synthesis. The prereplicative development of such stimulated calcium-deprived cells appears to stop at an advanced stage, because addition of calcium as late as 10 hours after serum exposure rapidly initiates DNA synthesis, and enables the culture's DNA-synthetic activity subsequently to reach its peak value at the same time as in control cultures.