Stimulation by thyrotropin and cyclic AMP of the proliferation of quiescent canine thyroid cells cultured in a defined medium containing insulin

Abstract
We have developed serum‐free primary cultures of differentiated follicular dog thyroid cells which allow the study of the hormonal control of cell proliferation. The cooperation of insulin and increasing cellular cyclic AMP by thyrotropin triggers the DNA synthesis and the proliferation. Dog thyroid cells are an example of a system in which cyclic AMP is a sufficient signal to stimulate the proliferation in quiescent cells.