VASOPRESSIN STIMULATION OF MOUSE 3T3-CELL GROWTH

Vasopressin is shown to be a potent mitogen for Swiss 3T3 cells. The hormone (1-10 ng/ml) causes a striking shift of the dose-response curve for the effect of serum on thymidine incorporation by cultures of 3T3 cells arrested in the G1/G0 phase of the cell cycle. In the absence of added serum, the effect of vasopressin on DNA synthesis is greatly potentiated by insulin, epidermal growth factor, and a factor isolated from medium conditioned by simian virus 40-infected baby hamster kidney cells. The mitogenic effect of vasopressin is dependent on time and hormone concentration. In the presence of insulin, the half-maximal effect elicited by the peptide is obtained at 0.6 ng/ml. [Arg]Vasopressin and [Lys]vasopressin are equally potent. The vasopressins are 103-fold more potent than oxytocin. In the presence of a low (2.5%) concentration of serum, vasopressins stimulate cell proliferation.