Oxytocin and vasopressin analogues capable of competition with vasopressin binding to rat liver membranes

Abstract

A number of vasopressin and oxytocin analogues modified in positions 1, 2, 4, 6 and 9 of the peptide chain were tested regarding their affinity to the rat liver membrane receptor. The affinities were estimated from the ability of the analogues to compete with the binding of tritiated vasopressin to rat liver membranes. In the series of vasopressin agonists, the degree of competition was in good agreement with the corresponding pressor activities. In the case of inhibitors of vasopressin pressor action, binding to the membrane system was also observed.