Ala-Gly- and Val-Asp-[Arg 8 ]-Vasopressin: Bovine Storage Forms of Arginine Vasopressin with Natriuretic Activity

Extracts of fresh-frozen bovine neurohypophysis were purified by chromatographic techniques to isolate and characterize the components that produce natriuresis in nondiuretic dogs. Two compounds with natiuretic properties similar to those of synthetic arginine vasopressin accounted for most of the natriuretic activity and appeared to be the prevalent vasopressin-like molecules in the extract. These peptides were Ala-Gly-[Arg8]-vasopressin and Val-Asp-[Arg8]-vasopressin; the natriuretic potency of each appeared to be similar to synthetic arginine vasopressin and could be observed with doses in the range of 50 picomoles. In the dog the most conspicuous difference between synthetic arginine vasopressin and the new vasopressin peptides was the smaller pressor responses to natriuretic doses of the new compounds.