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.