Abstract: | As was reported elsewhere (Gasparian, Grigorian, 1989a, 1989b), the stimulation of cell proliferation takes place in established culture of chick embryo cells after adding a suspension of living or inactivated homologous cells. In the present paper the kinetic parameters of this process, termed as the contact stimulation of cell proliferation, were studied. The dose- and time-dependence of cell response to the stimulus is described. It was shown that the addition of cells activates cell growth both in exponential and stationary cultures. DNA synthesis in resting cells is seen initiated only if their continuous interaction with the added cells is provided. The nature of signals involved in the process of contact stimulation is described. |