The effect of some structural changes in the molecule of vasopressin on the duration of antidiuretic action

Abstract

The effect of two structural variations in the molecule of [8-D-arginine]deamino-vasopressin on the prolongation of the antidiuretic action of the analogues in non-anesthetised rats was studied. The replacement of glutamine in position 4 of the peptide chain with a suitable amino acid has prolonged the half-life of the antidiuretic effect. A more prolonged antidiuretic effect was obtained when the stabilization of the cyclic structure of [8-D-arginine]deamino vasopressin was performed by replacement of the disulfidic bridge by the monocarba bridge. The binding and activating constants (adenylate cyclase) in a membrane fraction of the rat kidney were compared with the factors influencing the metabolic stability of the molecule of the individual analogues.