MEDIUM DEPLETION AND CONTACT INHIBITION OF REPLICATION: ABSENCE OF A SPECIFIC INHIBITOR

ABSTRACT The role of medium exhaustion in the regulation of contact inhibition of growth was studied in 3T3 cells and various other mammalian cell lines. the concept of a diffusable inhibitor which sustains contact inhibition was not supported by the experimental results. Used medium could be restored by dialysis against a fresh one and also by the addition of nutritional constituents of low molecular weight. The growth properties of several mammalian cell lines were studied. the results revealed an inverse correlation between the sensitivity to contact phenomena and the efficiency to utilize nutrients from the medium for replication.