Vasopressin antisense peptide interactions with the V1 receptor

The molecular recognition hypothesis, that peptide ligands and their receptor binding sites are encoded by complementary nucleotide sequences, was tested for arginine vasopressin (AVP) and its V1 receptor. Binding of [125I] [d(CH2)5,Sar7]AVP (a selective V1 vasopressin antagonist radioligand) or [3H]AVP to rat liver plasma membranes was inhibited by peptides known to bind to V1 receptors but not by the AVP complementary peptide (Ser-Ser-Trp-Ala-Val-Leu-Glu-Val-Ala) (PVA). Rabbit anti-PVA antibodies were nonimmunoreactive with any protein in rat liver membranes or in a partially purified preparation from rat liver containing reconstitutable vasopressin binding activity. Furthermore, there was no suppression of the AVP pressor effect by PVA in vivo using a rat blood pressure bioassay. These findings do not support the hypothesis that the V1 receptor binding site is encoded by the antisense DNA strand to AVP.