A substance P antagonist also inhibits specific binding and mitogenic effects of vasopressin and bombesin-related peptides in Swiss 3T3 cells.

While vasopressin and peptides of the bombesin family bind to different receptors in quiescent Swiss 3T3 cells, the antagonist [D-Arg1,D-pro2,D-Trp7,9,Leu11] substance P blocks the specific binding of both (3H) vasopressin and 125I-gastrin-releasing peptide to these cells. In addition, the antagonist inhibits the mobilization of Ca2+ and induction of DNA synthesis by vasopressin. These results indicate that [D-Arg1,D-Pro2,D-Trp7,9,Leu11] substance P has the ability to interact with the receptors for three structurally unrelated peptide hormones.